There are some spots around the world where energy literally bubbles to the surface. In Iceland, home to more than 200 volcanoes and dozens of natural hot springs, tapping into this energy isn't hard. Dotted around the country are steaming pools of water, heated by the geothermal fires that burn just below the crust. Boiling jets of water and steam are thrown into the air by geysers.

Iceland now heats 85% of its houses with this geothermal energy, while 25% of the country's electricity also comes from power stations that harness this heat from underground. It's an appealing prospect – an almost limitless supply of energy waiting to be tapped.  

But geothermal energy offers an essentially inexhaustible green energy source across the planet. And it's "always on'', unlike wind or solar power, since the heat is continually emitted from the Earth's molten core and the decay of naturally occurring radioactive elements in our planet's crust. Indeed, the Earth emits such enormous amounts of energy as it cools that the heat lost into space each year is enough to meet the world's total energy demands many times over.

The challenge is tapping into that energy. 

Currently only 32 countries in the world have geothermal power plants in operation. There are fewer than 700 power plants around the world, generating around 97 Terawatt hours (TWh) in 2023 between them. That is less than half the amount of electricity generated by solar in the US alone and far short of estimates for the potential contribution that geothermal could make to the global energy mix. Some estimate that geothermal could contribute around 800-1400TWh of electricity annually by the middle of the century with a further 3,300-3800TWh per year of heat. 

"The Earth itself has the potential to address a variety of hurdles in the transition to a clean energy future," argued Amanda Kolker, geothermal programme manager at the National Renewable Energy Laboratory (NREL) in the US, when releasing a report on the potential of geothermal energy in 2023. 

But not every country is as lucky as Iceland, where reservoirs of hot water at temperatures of around 120-240C (248-464F) can be easily accessed close to the surface. In other areas of the country, wells drilled to depths of up to 1.5 miles (2.5km) provide access to temperatures of up to 350C (662F). Iceland's main geothermal site at Reykjanes, for example, has drilled experimental wells down 2.9 miles (4.6km) to access superheated fluids as hot as 600C (1112F). Already, day-to-day heat extraction is taking place using shallower wells that draw on temperatures around 320C (608F) to generate 720 Gigawatt hours (GWh) of electricity per year.

One reason geothermal is not more widespread is the high upfront investment needed to extract that energy. But physically reaching it has also been beyond us so far.  

For other parts of the world to enjoy a part of this geothermal bonanza of clean energy, we need to drill deeper to reach the temperatures needed to generate electricity or provide large-scale heating for nearby neighbourhoods.

Across much of the planet, temperatures increase by 25-30C (77-86F) on average every kilometre you go down through the Earth's crust. In the UK, for example, the subsurface temperature at around 5km (3 miles) down is about 140C (284F), according to the British Geological Survey.

Drill down far enough, though and it is possible to reach a point where water temperatures surpass 374C (705F) at pressures above 220 bars (one bar being average pressure on the Earth's surface at sea level). This is where water enters an energy-intense state known as supercritical, where it exists in a form that is neither liquid or gas. The hotter and more pressurised it is, the greater energy it contains. 

In fact, a single superhot geothermal well could produce five to 10 times the energy that commercial geothermal wells produce today, according to the NREL. 

One major hurdle, however, is that conventional rotary drills – even those tipped with diamond – are ill-equipped to excavate to the kind of depths needed to access these kinds of temperature. In the mysterious deep underworld of uncertain geology, extreme temperatures and huge pressures, drill components can fail frequently, while keeping holes from becoming blocked is a constant battle. 

In 2009, for example, a team working on the Iceland Deep Drilling Project inadvertently tapped supercritical conditions when it drilled into a magma chamber at the Krafla volcano, about 1.2 miles (2km) below the surface. The superheated steam emitted from this well was highly acidic, making it difficult to use. The high pressures and temperatures involved also made it difficult to control, and it had to be intermittently discharged for around two years before a valve failure forced the hole to be sealed. 

Deep drilling can also be an expensive and time-consuming endeavour.

The deepest hole ever dug by humans dates back to the Cold War, however, when there was a race between the superpowers to drill as far into the Earth's crust as possible. The Soviets managed to plough their way through 7.6 miles (12.2km) of rock – creating the Kola Superdeep Borehole, on the Kola Peninsula, high in the Arctic Circle. It took them almost 20 years to reach that depth and it remains the deepest humans have managed to delve into the Earth. (Read more about the Kola Superdeep Borehole in this article by Mark Piesing.)

The NREL estimates that the cost of drilling a 1km deep well is around $2m (£1.57m) while drilling four times that depth can cost between $6m-$10m (£4.7m to £7.87m) with current technology.

Yet deep geothermal energy could provide some considerable cost savings when compared to conventional geothermal, due to the higher temperatures and pressures that can be accessed further into the Earth's crust. Some studies have suggested deep geothermal energy could supply heating for communities at costs similar to other forms of heating, such as using gas, but with fewer greenhouse gas emissions.

With this in mind, some pioneering researchers and companies are turning to new types of drills and drilling techniques to bore some of the deepest holes ever created in the hope of bringing geothermal energy to parts of the world that never thought it was possible.

Quaise Energy, a spin-off from the Massachusetts Institute of Technology (MIT), for example, are aiming to drill holes as deep as 12 miles (20km) to access temperatures of 500C (932F) or more. To do so, they are turning to a tool that draws on years of research into nuclear fusion power. "While others are putting shovels in the ground, we're putting microwaves in the ground for the first time," says the company's co-founder Matt Houde. 

He and his colleagues are experimenting with millimetre-wave directed energy beams that vaporise even the hardest rock. It focuses high-powered beam of radiation similar to microwaves but at a higher frequency onto a segment of rock, heating it up to 3,000C (5,432F) so that it melts and vaporises. By directing the beam so it bores through the rock, holes can be created without the debris and friction created by traditional drilling techniques.

"Millimetre-wave drilling is a process that can operate largely independent of depth," says Houde. "And millimetre-wave energy can also transmit through dirty, dusty environments."

The technology has grown out of nuclear fusion plasma experiments conducted by Paul Woskov, an engineer at MIT's Plasma Science and Fusion Centre. Millimetre-wave directed energy has been explored as a way of heating up plasma in nuclear fusion reactors since the 1970s, but a few years ago Woskov hit upon another use for the technology. He started using millimetre-wave beams generated by a device known as a gyrotron to melt through rock.

But so far the technology has only been tested in the laboratory, drilling shallow holes in relatively small samples of rock, but the company claims it can drill through rock at around 3.5m (11.5ft) per hour. While this is slow compared to traditional drilling techniques, there are other benefits as the "drill bit" isn't physically grinding through the rock, it should not wear out or need replacing. Quaise Energy are now at the final stage of laboratory testing of millimetre-wave technology prior to beginning field trials in early 2025. 

But transferring the millimetre-wave drilling technology from the laboratory to a full-scale drilling operation will still be a challenge.

"They have never been used before in the deep high-pressure subsurface environment," says Woskow. "Changes due to intense energy-matter interaction applied to drilling require a new learning curve." 

Slovakia-based GA Drilling, meanwhile, is exploring a different high-energy drill technology to bore into the Earth's crust. It is using a pulse plasma drill, based on very short high energy electric discharges that disintegrate rock without causing it to melt. This avoids creating any viscous molten rock, which can be difficult to remove and can stop drill bits penetrating further. "Since the process is very swift with short shocks crumbling the rock, there isn't time for melt to form – so the need to pull up and replace the bit is greatly reduced," says Igor Kocis, chief executive and chairman of GA Drilling. "Five to eight kilometres (3-5 miles) is a target for our current development programme – and later 10km-plus," he adds. "These depths will allow nearly universal access to geothermal power."  

Research into pulse plasma drills – using very short energy pulses that disintegrate rock using ionised gas as hot as 6,000C (10,832F) – is another avenue being explored by a European consortium led by the Geothermal Energy and Geofluids (GEG) group, with partners in Germany and Switzerland.

GA Drilling has also been collaborated with Konstantina Vogiatzaki, associate professor of engineering science at the University of Oxford to adapt advanced mathematics looking at how  supercritical fluids can be controlled when tapping deep earth energy sources accessed via plasma drilling. "We worked on defining the optimum combustion system for a full-scale drilling tool, opening new horizons in controlling ultra-high pressure combustion through plasma drilling," says Vogiatzaki. 

Others are looking beyond our own planet for ways to help us drill down into it. Technology developed for planetary exploration missions on the scorching surface of Venus, where temperatures can reach 475C (887F), are being adopted by geothermal drilling companies. Ozark Integrated Circuits – an electronics manufacturer based in Fayetteville, Arkansas – has been adapting circuits capable of withstanding extreme temperatures that can be used on deep Earth geothermal drilling rigs.

For its own part, the NREL has turned to AI to analyse complex subterranean environments to try to find the best places to drill for supercritical water, as well as helping to predict and detect faults with drills before they cause major issues.

And some companies are already making inroads into the deep Earth. Geothermal company Eavor told the BBC that in 2024 it reached a depth of three miles (5km) with two vertical wells at a site in Gerestried, Bavaria, Germany. It has been using two of the largest land-based drilling rigs in Europe in an effort to create a commercial-scale plant in Geretsried that aims to bring geothermal heat to the surface by circulating water inside a closed loop design it calls the Eavor Loop. The system works like a giant radiator, with cold water in the loop being heated underground and then coming back to the surface where it will be used to generate electricity and piped into nearby homes through a district heating system. Eavor expectes to begin generating energy at the site in the first half of 2025, says John Redfern, Eavor's CEO and president.

"Our technology is looking to drill up to 11km (6.8 miles) in the future," says geologist and Eavor co-founder Jeanine Vany. "I believe we can make meaningful progress towards unlocking superhot rock in the next three to five years."    

Their closed-loop approach also helps to avoid some of the contamination problems that can occur when superheated water is extracted from deep geothermal wells – as the Iceland Deep Drilling Project discovered in 2009. It can also help to reduce the emissions of hazardous gases, such as hydrogen sulphide, that open-loop geothermal systems can emit.

Vany also points out that deep geothermal energy doesn't need a lot of space on the surface, which means it could be slotted into urban locations in the future. 

But there are other problems to be overcome. It isn't yet clear how easy it will be to maintain deep geothermal wells and keep them from becoming blocked.

The drive to tap deep geothermal energy could also bring new life to ageing fossil fuel power stations as countries look to switch off their traditional carbon-emitting energy sources. Retrofitting old coal power stations into geothermal plants could be a way of giving the steam-powered generators a second life and help to speed up the construction of geothermal plants by taking advantage of existing electricity transmission lines. Woskov has identified an abandoned coal power plant in upstate New York, which he hopes could be reopened before the end of the decade to generate electricity from the heat deep underground.

There would be a certain poetry in that switch – a power station that once ran on a dirty fuel dug out of the ground finding new life in the clean energy revolution with an energy source from even deeper underground.

The question is – will they be able to dig deep enough?

When Formula E's Season 10 kicked off at Mexico City's Autodromo Hermanos Rodriguez in January, the roar of 40,000 spectators easily drowned out the mosquito whine of the 24 all-electric race cars zipping off the starting grid. Hurtling along at speeds upwards of 300km/h (186mph), some of the best drivers in the world jockeyed for position along the circuit.

Dreamed up in 2011 on the back of a napkin at a Paris restaurant, Formula E is now a decade old. It has 11 teams, with 22 drivers total, operating single-seater race cars similar in appearance to the famed open-cockpit vehicles of Formula One.

"The standard of driving is very high," says Graham Evans, director of auto supply chain and technology for S&P Global Mobility, an automotive intelligence firm. "These are very good guys who are also very experienced professional drivers."

Since its first season in 2014, Formula E has grown into a lucrative business. Intelligence company GlobalData estimates the championship's total sponsorship for the 2023-2024 season at $102.5m (£81.36m), with international viewership and attendance estimated at 344 million worldwide in 2023.

The batteries in the current generation of Formula E cars deliver up to 350kW of power, and can propel a driver to a maximum top speed of 320km/h (199mph), approaching the top speed of traditional F1 cars. And while the racing series may not have the pedigree – or budget – of F1, it does provide a unique and important testing ground for new battery technology that could benefit the entire EV industry. 

The competition among engineering firms to design batteries for Formula E is fierce, says Ashley Nunes, an associate and researcher at Harvard University's department of economics, who studies the electric vehicle market. Only a handful of elite companies can build these batteries to the specifications required to compete in a world-renowned race. 

The companies who've won bids include WAE, McLaren, Podium Advanced Technologies and Atieva, the technology arm of luxury EV brand Lucid Motors. Most of these companies already have a pedigree of building high-performance tech, including batteries, for the biggest internal combustion engine (ICE)-powered racing series in the world, Formula 1. While designing this technology may bring in more revenue for these companies in the short term, there's plenty of money to be made in engineering battery technology for Formula E.

The technology is far more expensive than the batteries found in a typical road EV, and for good reason. A Tesla Model S going all-out on a racetrack will start slowing down as the battery charge gets depleted, says Evans. That's because the battery isn't capable of handling sustained race performance. By contrast, any petrol or diesel-powered car can stay at top speed even on a quarter of a tank. A Formula E battery needs to behave more like its ICE kin at all times. "It's got to deliver sustained high performance," says Evans.

On top of offering enough power for incredible bursts of speed, a Formula E battery needs to remain as light as possible. Race regulations require it to weigh just 284kg (626lbs), roughly a third of the car's total weight including the driver, and be capable of ultra-fast charging during a race. Plus, batteries get hot when overused, so they need an elaborate cooling system. All those requirements create tremendous engineering challenges (and capital requirements) for whichever company is tapped to build a Formula E battery. 

"The margins are probably relatively small, but because there aren't many producers, you can charge a premium for them," says Evans. According to the Fédération Internationale De L'Automobile (Fia) – the regulatory body for both Formula 1 and Formula E – the GEN3 battery system's total cost for Formula E's 2022-2023 season was €264,812 ($268,000; £226,442). "The people who are paying that price are multi-billion-dollar companies like Mercedes and Ferrari," says Nunes." They have deep pockets."

Formula E battery suppliers don't just earn money from the batteries themselves. The process of developing new battery pack configurations, cooling systems and fast-recharge techniques can all be patented. If a Formula E supplier creates a revolutionary new technology for the track, says Evans, and licenses it to a mainstream EV automaker building millions of units a year, the licensing fee alone could be well worth the investment.

Plenty of innovations for everyday cars, like tire pressure gauges, had their origins in F1. But Nunes points out that the battery requirements for road EVs are very different from their ultra-competitive cousins. Drivers want high range, large capacity and longevity that simply aren't necessary for Formula E, whose batteries don't need to last for a decade or more of driving.

Experts are already watching some new battery developments. One is fast charging. Formula E vehicles use ultra-fast DC charging to reach top speeds, while passenger EV's use a slower AC charge that provides greater range. Still, many automakers in the commercial EV industry are keen to gain insight into Formula E charging technology as it rapidly evolves.

To Evans, the biggest innovation might come through immersion cooling, a system where Formula E batteries are immersed in a refrigerant called dielectric fluid. The result is a significantly cooler battery capable of long-lasting high performance. Combined with ultra-fast charging, he says the racetrack can serve as an incubator for EV development overall.

"In terms of being able to deliver that really high-powered challenge, Formula E can help us understand the art of the possible," says Evans. 

On a laboratory bench in Cambridge, Massachusetts, a stack of polished cylinders of black-coloured concrete sit bathed in liquid and entwined in cables. To a casual observer, they aren't doing much. But then Damian Stefaniuk flicks a switch. The blocks of human-made rock are wired up to an LED – and the bulb flickers into life.

"At first I didn't believe it," says Stefaniuk, describing the first time the LED lit up. "I thought that I hadn't disconnected the external power source, and that was why the LED was on. 

"It was a wonderful day. We invited students, and I invited professors to see, because at first they didn't believe that it worked either."

The reason for the excitement? This innocuous, dark lump of concrete could represent the future of energy storage.

The promise of most renewable energy sources is that of endless clean power, bestowed on us by the Sun, wind and sea. 

Yet the Sun isn't always shining, the wind isn't always blowing, and still waters do not, in megawatt terms, run deep. These are energy sources that are intermittent, which, in our energy-hungry modern world, poses a problem.

It means that we need to store that energy in batteries. But batteries rely on materials such as lithium, which is in far shorter supply than is likely to be needed to meet the demand created by the world's quest to decarbonise its energy and transport systems. There are 101 lithium mines in the world, and economic analysts are pessimistic about the ability of these mines to keep up with growing global demand. Environmental analysts note that lithium mining uses a lot of energy and water, which nibble away at the environmental benefits of switching to renewable energy sources in the first place. The processes involved in extracting lithium can also sometimes lead to toxic chemicals leaking into local water supplies.

Despite some new discoveries of lithium reserves, the finite supply of this material, the over-reliance on just a handful of mines around the world and its environmental impact have driven the search for alternative battery materials.

This is where Stefaniuk and his concrete come in. He and his colleagues at Massachusetts Institute of Technology (MIT) have found a way of creating an energy storage device known as a supercapacitor from three basic, cheap materials – water, cement and a soot-like substance called carbon black.

Supercapacitors are highly efficient at storing energy but differ from batteries in some important ways. They can charge much more quickly than a lithium ion battery and don't suffer from the same levels of degradation in performance. But supercapacitors also release the power they store rapidly, making them less useful in devices such as mobile phones, laptops or electric cars where a steady supply of energy is needed over an extended period of time.

Yet according to Stefaniuk, carbon-cement supercapacitors could make an important contribution to efforts to decarbonise the global economy. "If it can be scaled up, the technology can help solve an important issue – the storing of renewable energy," he says.

He and his fellow researchers at MIT and Harvard University's Wyss Institute for Biologically Inspired Engineering, envisage several applications for their supercapacitors. 

One might be to create roads that store solar energy and then release it to recharge electric cars wirelessly as they drive along a road. The rapid release of energy from the carbon-cement supercapacitor would allow vehicles to get a rapid boost to their batteries. Another would be as energy-storing foundations of houses – "to have walls, or foundations, or columns, that are active not only in supporting a structure, but also in that energy is stored inside them", says Stefaniuk.

But it is still early days. For now, the concrete supercapacitor can store a little under 300 watt-hours per cubic metre – enough to power a 10-watt LED lightbulb for 30 hours. 

The power output "may seem low compared to conventional batteries, [but] a foundation with 30-40 cubic metres (1,060-1,410 cubic feet) of concrete could be sufficient to meet the daily energy needs of a residential house", says Stefaniuk. "Given the widespread use of concrete globally, this material has the potential to be highly competitive and useful in energy storage."

Stefaniuk and his colleagues at MIT initially proved the concept by creating cent-sized 1V supercapacitors from the material before connecting together in series to power a 3V LED. They have since scaled this up to produce a 12V supercapacitor. Stefaniuk has also been able to use larger versions of the supercapacitor to power a handheld games console.

And the research team are now planning to build larger versions, including one up to 45 cubic metres (1,590 cubic feet) in size that would be able store around 10kWh of energy needed to power to power a house for a day. 

The supercapacitor works due to an unusual property of carbon black – it is highly conductive. This means that when carbon black is combined with cement powder and water, it makes for a kind of concrete that is full of networks of conductive material, taking a form that resembles ever-branching, tiny roots.

Capacitors are formed of two conductive plates with a membrane in between them. In this case, both plates are made of the carbon black cement, which were soaked in an electrolyte salt called potassium chloride.

When an electric current was applied to the salt-soaked plates, the positively-charged plates accumulated negatively charged ions from the potassium chloride. And because the membrane prevented charged ions from being exchanged between the plates, the separation of charges created an electric field. 

As supercapacitors can accumulate large amounts of charge very quickly, it could make the devices useful for storing excess energy produced by intermittent renewable sources such as the wind and solar. This would take the pressure off the grid at times when the wind is not blowing, nor the Sun shining. As Stefaniuk says, "A simple example would be an off-grid house powered by solar panels: using solar energy directly during the day and the energy stored in, for example, the foundations during the night."

Supercapacitors are not perfect. Existing iterations discharge power quickly, and are not ideal for steady output, which would be needed to power a house throughout the day. Stefaniuk says he and his colleagues are working on a solution that would allow their carbon-cement version to be tuned by adjusting the mixture, but they will not disclose the details until they have finalised the tests and published a paper.

There could be other issues to overcome too – adding more carbon black allows the resulting supercapacitor to store more energy, but it also makes the concrete slightly weaker too. The researchers say any uses that have a structural role to play as well as energy storage would need to find an optimum mix of carbon black.

And while carbon-cement supercapacitors could help to reduce our reliance on lithium, they come with their own environmental impact. Cement production is responsible for 5-8% of carbon dioxide emissions from human activity globally, and the carbon-cement needed for the supercapacitors would need to be freshly made rather than retrofitted in existing structures.

Nevertheless, it seems to be a promising innovation, says Michael Short, who leads the Centre for Sustainable Engineering at Teesside University in the UK. The research "opens many interesting potential avenues around the use of the built environment itself as an energy storage medium", he says. "As the materials are also commonplace and the manufacture relatively straightforward, this gives a great indication that this approach should be investigated further and could potentially be a very useful part of the transition to a cleaner, more sustainable future."

But more research will be needed to move this from the laboratory into the real world.

"Often, new discoveries are problematic when considerations are made to move from lab or bench scale to wider deployment at larger scales and volumes. This can be due to manufacturing complexities, resource scarcities, or sometimes due to the underlying physics or chemistry. Desirable properties occurring at smaller scales may reduce or even vanish when attempts are made to make it larger."

But there may be a way of overcoming the problem of environmentally-unfriendly cement, adds Short. His colleagues at Teesside University are already working on low-emissions cement that is made from the by-products of the steel and chemical industries.

Projects such as low-emissions cement and energy-storing concrete raise the prospect of a future where our offices, roads and homes play a significant part in a world powered by clean energy.

For decades now, scientists have been warning that without action to combat emissions, some low-lying islands will literally disappear beneath the waves. Many others will become uninhabitable as extreme weather increasingly batters their coastlines.

As the world edges closer to a long-term average of 1.5C warming, these warnings are becoming a seriously imminent prospect for some island nations. Five islets in the Solomon Islands, a nation of hundreds of islands in the South Pacific, have already been completely lost to sea level rise. And many small island developing states are seeing substantial annual economic losses due to coastal floods. By 2050, coastal flooding is set to triple across these nations, increasing annual economic damages by nine to 11 times.

Small islands have become a strong voice in international forums, pushing for more ambitious climate policies to curb global temperature rise, and were key to the 2015 Paris Agreement to pursue efforts to limit temperature rise to 1.5C. But they are increasingly facing some stark choices about how to physically stay above the waves, as well as in their diplomatic pushes for money to weather an increasingly uncertain climate.

Speaking at the closing plenary of COP29 in Baku, Azerbaijan, Toeolesulusulu Cedric Schuster, the Samoan chair of the Alliance of Small Island States (Aosis), told delegates that "time is not on our side" and urged them to implement ambitious climate plans. "[We] cannot do this alone," he said, adding that small islands required "transformational change" in access to climate finance. (Read more about the trillion-dollar climate puzzle that's become a diplomatic nightmare).

From reclaiming land from the sea to selling citizenship, the BBC looks at some of the measures already being taken to save these low-lying nations.

With sea-levels rising, one obvious response is to create new land. This has been the approach of the Maldives, a low-lying 1,200-island archipelago some 400 miles (644km) south of India.

The Maldives has the lowest terrain of any country in the world, and studies have concluded flooding here could eventually become too high for it to sustain habitation, leading to inevitable migration away from the islands. In a bid to protect itself, support a growing population and develop its economy, the Maldives has for decades now been working on a huge project of land reclamation. According to one paper, at least 186 of its 1,149 islands have some reclaimed land. More projects are on the way.

Land reclamation consists of dredging up sediment from the ocean floor to extend coastlines. But there has been concern from scientists, locals and human rights groups about the environmental and social impacts of the practice. Land reclamation can be harmful for natural coastal ecosystems such as coral reefs and mangroves, themselves hugely important for the coastal resilience of low lying islands. Natural shorelines are transitioning to artificial ones, resulting in even greater coastal erosion.

With these natural protections destroyed or undermined, flooding risk can go up. According to one paper, most of the inhabited islands in the Maldives now exhibit an "altered-to-annihilated capacity to respond to ocean-climate pressures". A 2023 paper found that land reclamations in the Maldives "lack a systematic approach" to anticipate sea-level rise and fail to account for local flood risk in their design and location choices.

The UN's climate body, the IPCC, has warned that land reclamation can become "a vicious cycle" for islands. By degrading ecosystems such as reefs and mangroves, land reclamation can compromise the protection they offer to island communities, and thus actually increase their exposure and vulnerability, according to the IPCC.

Responding to these concerns, Ali Shareef, the Maldives' special envoy for climate change, told the BBC that with 99% of the country's territory being ocean, land scarcity remains among its most pressing challenges. "As such, reclamation has become a necessary strategy to cater the needs of our growing population and to create new economic opportunities," he says. "However, we have regulations in place to minimise the impacts and damages."

Shareef adds that in recent years the Maldives has placed "a strong emphasis" on nature-based solutions, including mangrove and coral reef restoration, as well as attempting to minimise the impacts of construction on shorelines.

However, he acknowledges that there are still knowledge gaps. "We recognise the critical importance of balancing development with environmental sustainability," he says. "This has led us to integrate climate resilience and ecosystem protection into our reclamation projects. A key example is the Ras Malé eco-city, designed to be raised 3m (10ft) above sea level and powered entirely by renewable energy."

The most common measure used on islands to protect coasts, however, are seawalls. These promise a dual benefit of preventing soil sliding away (coastal erosion) and protecting the shoreline from waves and flooding.

However, poorly constructed seawalls can collapse: on Indian Ocean islands such as Seychelles, the shorelines are "littered with broken seawalls and groynes", according to the IPPC (groynes are protective structures which lie perpendicular to the shore). Seawalls can shift problems of shoreline erosion and lowland inundation elsewhere: in one case, a seawall erected to protect a village in Samoa was not long enough to protect all the houses, leading some families to face increasing impacts from large waves.

Nature-based defences, such as restoring mangroves, coral reefs and seagrass meadows which can protect people from coastal flooding and storms, are also becoming a priority for  many small islands. Other ways of weathering disasters are also getting higher interest, such as improving weather monitoring and early warning systems, or strengthening infrastructure to better weather extreme weather.

All this takes money, however, and where to get the rising amounts needed for such protection is not an easy challenge. Nor is sea-level rise the only climate threat to low-lying island nations. The highly disaster-vulnerable Caribbean island of Dominica is one country with an unusual, and potentially risky, strategy here.

Back in September 2017, shortly after Dominica was hit by the rapidly intensifying, category five Hurricane Maria which cost it some $1.3bn (£1bn), or 226% of its GDP, the country pledged to become "the world's first climate-resilient" nation.

"Our devastation is so complete that our recovery has to be total," prime minister Roosevelt Skerrit told the UN General Assembly at the time. The situation, he said, presented a unique, if unchosen, opportunity to be an example to the world of how "an entire nation rebounds from disaster" and "can be climate resilient for the future".

Dominica quickly drew up a plan to improve its climate resilience and better manage future disaster response. The country focused on developing its infrastructure for monitoring weather and water and early warning systems for disasters. It installed huge tankers to supply clean water in case of another hurricane or drought. It also rebuilt its seismic monitoring network, destroyed during Hurricane Maria: an essential step for one of the most seismically and volcanically active islands in the Caribbean. A landslide-prone country, it began planting more native plants and building other infrastructure to help stabilise slopes.

The unusual part, though, is the source of cash it is using to fund much of this: selling citizenship. Dominica has been selling passports – including to people who have never set foot on Dominica – since the 1990s. After recently doubling the price, it now costs $200,000 (£160,000), via a donation to its Economic Development Fund, or a real estate investment. The programme has ballooned in recent years, with revenues reaching 25-30% of its entire GDP.

Not all this money is going into resilience, and Dominica has other sources of funds too, but the long-term viability of relying on the passport income as a strategy to increase resilience against climate change is not assured. Concern is growing internationally around such citizenship schemes, which promote visa-free travel to a number of countries as one of the main benefits to customers. In 2023, the UK withdrew visa-free travel for citizens of Dominica over security concerns about citizenship being granted to people who posed a risk to the UK. A 2023 EU Commission report concluded Dominica had issued far more passports than officially stated. The EU commission raised security concerns about the trade, proposing a suspension in its visa-free regime for countries selling citizenship.

A 2024 report from the International Monetary Fund (IMF) on Dominica noted that recent international scrutiny of citizenship-by-investment schemes "threatens the viability" of financial flows for post-disaster reconstruction and development.

The government of Dominica did not respond to a request for comment.

So where else can these small developing island countries get the money needed to fight climate impacts?

Climate-vulnerable nations have long been pushing for more access to money from historically large economies to help them reduce emissions and deal with the impacts of climate change. Such climate finance, delivered via grants and low-interest loans, has become a key tenet of climate justice for impacted countries less responsible for global emissions. It currently amounts to just over $100bn (£79.8bn) per year.

Many island states are becoming increasingly frustrated with slow progress at UN climate talks, especially when it comes to delivering money to support countries vulnerable to climate impacts.

A key focus for COP29 was for countries to agree on a promised new target for climate finance going forwards, with many developing countries pushing for at least $1.3tn (£1.03tn) and small island states pushing for $39bn (£31bn) within this specifically for them. In the final hours of the conference, Aosis temporarily walked out of the finance talks. Speaking just after COP29 concluded in late November 2024, Michai Roberts, lead negotiator on finance for Aosis, told the BBC that other countries were "laughing at them" for asking for larger sums of money to help them tackle climate change. "The size of the damage to our economies [from climate change] outweighs any sort of per capita calculation of how much money we're getting," he said, adding that Aosis has always been "pragmatic" in the UN talks.

The final agreement landed on $300bn (£238bn) a year, less than a quarter of the suggested, more ambitious target.

In a statement, Marshall Islands climate envoy Tina Stege said the conference had seen "the very worst of political opportunism". "We are leaving with a small portion of the funding climate-vulnerable countries urgently need," she said. "It isn't nearly enough, but it's a start."

In August 2024, Papua New Guinea’s prime minister James Marape announced the country was pulling out of COP29 as a "protest at the big nations" with large carbon footprints for their "lack of support" to climate victims and forest and ocean nations.

Along with the Indonesian provinces of Papua and West Irian Jaya, Papua New Guinea is home to the world's third largest rainforest, the biggest in Asia. It's also highly vulnerable to climate change, with a dispersed population highly reliant on subsistence farming and susceptible to climate-induced natural disasters such as extreme weather, storm surges, sea-level rise and coastal inundation.

"Our economy needs money yet we are preserving trees as the lungs of the Earth, whilst industrialised nations keep on emitting," Marape said. "You have not paid for any conservation."

But climate advocates have warned a move to stop attending such talks could have the opposite effect, isolating the country from climate discussions and weakening its ability to access climate finance. And in the end, Papua New Guinea did send a delegation, although Marape did not attend. From Papua New Guinea, he urged "genuine action on preserving the world's rainforests", adding that he hopes rainforest nations will have a stronger voice at next year's COP30 in Brazil.

Other islands frustrated with the lack of movement on climate finance have been taking a different tack. Barbados prime minister Mia Mottley has become a well known name at climate talks due to her campaign to reform international finance, especially with regards to debt cancellation and restructuring, to help vulnerable countries better afford measures to cut emissions, adapt to climate change and deal with climate disasters.

At an opening speech at COP29 in Baku, Azerbaijan, in November 2024, Mottley urged delegates to loosen the "economic noose of tightening fiscal space" by delivering "urgently needed financial reforms". She called for developed countries and carbon producers to boost climate money without increasing debt in "already burdened" developing countries using global levies on stock and bond trades, shipping and fossil fuel extraction.

Barbados, a Caribbean nation of 280,000 people vulnerable to sea level rise and intensified tropical storms due to climate change, has already launched an ambitious adaptation plan to protect people and infrastructure from extreme weather. Mottley has previously warned that migration from Caribbean states will soon become a reality without emissions cuts and finance for resilience projects.

Her Bridgetown Initiative, launched in 2022, calls for a host of changes to multilateral money lenders such as the IMF and World Bank, including "natural disaster clauses" to automatically suspend debt servicing when climate disasters hit. Barbados has also joined other islands such as Belize and the Seychelles in setting up "debt-for-nature" swaps, where foreign debt is cancelled in exchange for local investments in conservation. (Read more about the deal that saved the Seychelles' troubled waters.)

Public debt levels in developing countries reached $29tn (£23tn) in 2023, and has grown twice as fast as in developed countries since 2010. Small island developing states are particularly exposed: they had an average external debt of 48-51% of gross national income from 2011 and 2019, and 40% of are either highly indebted or are pushing towards debt distress, according to a report last year.

A higher frequency of climate disasters is just one reason why many are urging a rethink on how money is lent to poorer countries. And Mottley is not the only leader calling for a step change on debt when it comes to climate impacts. A joint letter signed by the prime ministers of Antigua and Barbuda, Saint Vincent and the Grenadines and Grenada in July 2024 outlined this need following the "horrific devastation wrought by Hurricane Beryl" on small island economies.

Addressed to the UK government, the letter called for immediate debt cancellation in all three countries and a "Marshall Plan" for small island states, in reference to the US programme of support to postwar Europe in the late 1940s.

"Many small islands are struggling with insupportable debt burdens caused not by fiscal profligacy, but the elevated cost of repeated rebuilding after intensifying climate-related shocks for which they bear no responsibility," the letter read.

"Rich and big countries are largely responsible for accumulated emissions, and most able to evade their debilitating consequences. So they owe it to small islands to drastically change this palpably unfair and inequitable settlement."

Some small island states are now taking to international courts as another avenue to push richer countries to act on emissions and deliver climate finance, including the requests for money to cover the loss and damage from climate impacts, long a topic of fierce tension at climate talks.

In 2023, Vanuatu, a Pacific nation made up of around 80 low-lying islands, won its bid for an advisory opinion from the International Court of Justice (ICJ) on the legal obligation of states to reduce their impact on the climate and wider environment. The case is set to open in early December 2024, and while the legal view will be non-binding, it could be cited in climate court cases around the world.

Other court rulings brought about by islands have already been given. In September 2022, eight Torres Strait Islander people won a legal action against Australia at the UN's Human Rights Committee for climate-induced damages to their ancestral lands. It was the first legal action brought, and won, by climate-vulnerable inhabitants of low-lying islands against a nation state.

And in a May 2024 advisory opinion, the International Tribunal for the Law of the Sea expanded the definition of marine pollutants to include greenhouse gases. In a ruling requested by a coalition of nine small island states led by Antigua and Barbuda and Tuvalu, the tribunal stated that countries have a legal obligation to reduce their greenhouse gas emissions due to their current legal obligations to reduce marine pollution. This advisory opinion has "no binding force", but could be cited in other domestic and international court rulings. (Read about the other legal battles changing the course of climate change.)

Some islands are acknowledging, though, that there are some places that no amount of money will be able to save. In Fiji, an archipelago of more than 300 islands where dozens of coastal villages may soon be underwater, for example, the government has begun a careful village relocation programme. One local community has mandated that young adults building their family home should do so up-slope from the existing village, which is regularly flooded, to allow it to slowly transition away from danger.

Other nations are planning for relocation outside their historic islands. Tuvalu, an atoll nation of nine coral islands in the Pacific Ocean, is already facing the fact that, within decades, much of its land mass may no longer lie above sea level. Yearly damages due to flooding by the end of the century could amount to over 70% of its GDP, one paper found. Confronting the possibility of disappearing as a nation altogether, its leaders have decided to build the world’s first digital copy of a country, backing up everything from its houses to its beaches to its trees. (Read more about Tuvalu's race to upload itself to the metaverse).

As its citizens leave the island, Tuvalu hopes that the project could help to preserve its sovereignty. It has even enshrined a new definition of statehood in its own constitution, which is being increasingly recognised by other countries.

At a high level UN meeting in September 2024, small-island states issued a joint declaration affirming their right to retain statehood, sovereignty and UN membership, regardless of the course of sea level rise. Fiame Naomi Mata'afa, prime minister of Samoa and chair of Aosis, said in a release that island states have "stayed firm" for over 20 years and that "our states, maritime zones, and rights remain intact under international law, no matter the rising seas: we are here to stay".

There may always be a way to keep something of the islands set to be lost to climate change. But few are ready to give up the fight for their territories to remain as real, liveable islands for their citizens.

Vale of Glamorgan council said it was seeking urgent clarification from Aviva for its plans for the site.

The privately-run venture, which was backed by Aviva Investors, was given the go-ahead in 2018, despite protests and petitions over pollution fears.

But since then, it has been at the centre of a long-running planning row, remaining idle while waiting for the go-ahead to start operating.

In 2021, it faced an order to shut down.

In a statement, Aviva Investors said it had "made the decision to divest from the assets" in Barry, plus English sites at Hull and Boston.

A spokesperson for Aviva Investors said: "Since the original investment, it has become apparent that the gasification technologies at these plants have significant challenges in their current form.

"The assets have therefore not performed as we expected."

Following an independent review earlier this year, and informing investors of the situation, the decision was taken to move away from the sites.

The Docks Incinerator Action Group (DIAG) which has opposed the plant, said it was happy with the decision. It said it hoped no other company would take on the project.

Council leader Lis Burnett said the plant had "failed to conform" with its original planning permission.

“Two retrospective planning application were refused in March, decisions that are currently being appealed," she said.

“We will now seek urgent clarification from Aviva regarding those appeals and its plans for the site.”

Barry Biomass has previously described the Barry site as environmentally responsible, safe and with a positive long-term impact on the local community.

On April 20, 2010, a blowout caused a huge explosion on the offshore drilling rig operated by BP in the Gulf of Mexico. Eleven people were killed. Two days later, the rig collapsed. Oil began seeping into the sea, and it continued to flow for almost three months.

The Deepwater Horizon disaster is among the most lamented environmental catastrophes of the past century. It's hard to comprehend how incredibly huge the spill was. It was the world's largest ever marine oil spill, releasing an estimated 4.9 million barrels of crude oil (779 million litres, or over 300 Olympic swimming pools-worth). Up to a million seabirds were killed outright, and the human health and socioeconomic effects are still being felt today.

BP, rig operator Transocean, and several government agencies immediately tried to limit the damage, with BP's chief executive saying the company was "determined to do everything in our power" to contain the spill. Booms were deployed to try to contain the oil, skimmer ships nibbled at the edges of the widening slick and fires were set to try to burn it off the sea surface. Various devices were deployed deep below the surface to try to contain or capture the oil. BP also began to spray the oil with enormous amounts of dispersants both on the sea surface and 1.5km (0.9 miles) underwater, where oil was gushing from the wellhead.

However, it is thought that these measures recovered or dispersed only around a third of the spilled oil. The BP spill sparked a huge amount of research into oil spills and their impacts. But 14 years on, what hope is there for better measures should another oil spill occur?

Jeffrey Short, an expert in oil spills and now-retired scientist from the US National Oceanic and Atmospheric Administration (Noaa), was working for Oceana, a marine conservation organisation when the BP spill occurred. When a colleague told him about the spill at lunchtime, he felt sick.

"I knew immediately that this would be ecologically and economically disastrous, that it would wreck tens of thousands of people's lives, and that it would dominate my professional life for the next several years," he says. "All of which proved true."

Oil spills are the third largest source of oil in the sea, after land-based runoff (largely from cities and vehicles) and natural oil seeps. The problem with spills, of course, is the sheer volume of oil that enters the sea all at once. This means that oil spills – especially big ones – are "much, much more dangerous per unit oil released", says Short.

While no spill has since surpassed Deepwater Horizon's in sheer volume, Noaa responds to more than 150 oil spills every year. Just last month, oil began spewing from a submerged oil tanker and at least two other sunken vessels in Manila Bay, in the Philippines, after they were hit by monsoon rains and Typhoon Gaemi. Another oil tanker hit by projectiles from Yemen's Houthi movement remains in a precarious position in the Red Sea. However, the number of oil spills from tankers is today far lower than in the 1970s, due to improved standards.

When oil spills occur, the first step is to control the source, "whether that be a ship, pipeline, or leaking well", says Doug Helton, regional supervisor of the emergency response division at Noaa's Office of Response and Restoration. "The second priority is recovering oil at sea."

The major priority is to avoid the oil reaching the shoreline, where it can do the most damage. Shoreline cleanups can last days to years, depending on the type of oil and severity of contamination, says Helton.

Spilt oil tends to spread quickly into a thin layer on the sea surface. Within days, centimetres-thick layers become a film of a millimetre or less, spread in drifting patches over a wide area. Efforts to scoop up the oil from the sea surface therefore offer diminishing returns as time goes on. "Floating oil spreads very quickly and there is a limited window of time – days – when at-sea tools are effective," says Helton.

Hundreds of skimmers were deployed to clean up the BP Deep Horizon spill. Skimmers are boats that scoop up spilled oil from the water's surface, usually after the slick is first surrounded with floating booms to keep it from spreading. They do this in various ways – some, for example, suck up the oil like a vacuum cleaner, while others use oil-attracting "conveyor belts" or gravity to carry the spilled oil into a reservoir.

But hopes at the time that the skimmers could pick up oil "like a lawnmower cutting grass" proved to be overblown. They only recovered an estimated 3% of the oil. "At sea, the oil may spread more rapidly than the skimming vessels trying to capture oil," says Helton. "Going faster is not an easy option because the bow wave from the ship will push the oil away."

The satellite photos of the BP disaster "speak volumes", says Short. "You'll see a half a dozen surface skimming boats that, from the sea surface next to the boat, look quite large and quite effective. But from a satellite, you realise that you are [...] just having a nearly negligible effect on the size of the spill."

In fact, a 2020 review of 30 large offshore oil spills found only 2-6% of oil was recovered using mechanical methods like skimmers. Short says that mechanical recovery has improved in recent decades, with better booms to corral the oil and better systems to remove it from the sea surface. But even with improvements, mechanical methods can't have much impact on a large spill, he says.

In recent years a plethora of studies and reports have emerged looking at different ways to soak up oil spills, from laser-treated cork and textiles based on leaves to graphene, magnets and even hair and fur. These mostly rely on the oil-attracting and water-hating properties of the material, with various forms of oil-attracting sponges a particularly common solution. But the difficulty of handling oil-soaked materials means these techniques are typically only useful for small spills.

When Guihua Yu, a professor of materials science at the University of Texas at Austin, and his team began considering whether a new material his lab was working on could be used to help clean up oil spills, he says he was surprised about the lack of focus on how these innovative materials could be used in practice.

One central problem, he says, is that most can only be used in a non-continuous way, requiring processing to remove the oil before the same material can be used again.

Yu and his team landed on a solution which he thinks could help. In a 2023 paper, his lab developed a prototype with a collection speed 10 times faster than current clean up rates.

The lab produced their own super oleophilic gel capable of 99% separation of oil from water, which they used to cover a mesh filter. But they also designed a continuous roller system, which Yu says would be attached to the front of a ship. This conveyer belt picks up oil from the water surface, then rolls it round to beside an induction heater, which heats the oil, detaching it and allowing it to drip down to a collector in the middle. The roller is freed up to be directly reused as it rolls down to the water again.

"The most important [innovation in our work] is probably higher throughput," says Yu. "I personally felt it's very unique and very different from what is conventional."

The invention has so far only been tested on a small motor oil spill in a lake in China using a metre-scale prototype, but Yu says he has had conversations with industry potentially interested in scaling it up. The overall costs, he believes, would be reasonable. However, he admits his current design does not address the bow-wave issue of oil being pushed away from the ship, noting that how to balance collection and bow wave is "worthy of further investigation".

But Short says that, for large spills which require more than a day to clean up, movement of oil during the night (when operations can usually not be carried out) will always limit the efficacy of collecting oil on the sea surface.

"The following day, the oil must first be located before response equipment can be effectively deployed," he says. "For large spills, especially when response equipment is limited, these challenges may limit the amount of recoverable oil to less than 10% of the initial spill volume."

Still, improvements have been made in tracking the oil too. Noaa now uses drones and satellites to help find and track oil spills, and tools for mapping and coordination have advanced. Undersea manned and autonomous tools that can tap into sunken vessels to extract oil have also been developed since the Deepwater Horizon spill, says Helton.

Burning is another, more controversial, way to remove floating oil at sea. An estimated 5% of the BP oil spill was burnt off the surface.

Burning requires concentrating the oil on the sea surface to at least 2-3mm – relatively thick for an oil spill. It also requires quick action, and lucky weather conditions. In the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989, a storm dispersed the oil over a wide area into a film too thin to catch alight.

Improved boom designs to better corral oil have improved the effectiveness of burning over the years, says Short. But successful burning also has its own problems for the environment and human health in the form of air pollution.

The impacts of air pollution on the workers attempting to clean up the BP oil spill are still being investigated today. A major 2022 study found that workers involved in cleaning up the spill were 60% more likely to be diagnosed with asthma or experience asthma symptoms one to three years after the spill, compared with those who did not work on the cleanup.

Burning is not the only culprit for air pollution. The evaporation of the oil itself is also highly toxic, as is another controversial way to try to dissipate the impacts of oil spills: dispersants.

During the Deepwater Horizon disaster, BP sprayed roughly 1.84 million gallons (8.37 million litres) of the dispersant Corexit on the surface and deep into the water column – the largest volume of dispersant ever used for an oil spill.

Dispersants work by breaking down the oil into smaller droplets that can mix with the water below, which both helps it to degrade and removes it from the surface, where it tends to do most damage (especially to diving seabirds, surfacing marine mammals, turtles and young fish). But it needs to be added quickly after oil spills.

Little was known about exactly how this quantity of dispersant would affect the environment in the BP spill, but the hope was that it would stop the oil from reaching shoreline habitats. But the sheer volume used has been widely criticised as largely ineffective as well as harmful to the environment and humans. It's thought just 8% of the oil was dispersed using Corexit.

In Short's view, prior knowledge about oil spills meant that in the Deepwater Horizon spill "you can be quite certain in advance" that the continued application of dispersants on parts of the oil slick which had already emulsified was "a waste of time" beyond the first few days. "But it shows the public that you're doing something."

Environmentalists and scientists have a term for these kinds of reactions to oil spills – "response theatre". It describes when companies responsible for a spill focus more on being seen to do something about the spill than necessarily doing the best thing.

Some researchers, however, say the dispersants were relatively effective and may have helped avoid further air pollution by getting rid of the oil. A 2019 report from the US National Academies found that dispersants can help cope with oil spills in some circumstances, but that limitations in the research make it hard to make conclusions about whether it improves the human health aspect compared to not using dispersants.

Still, counterintuitive as it may sound, there are occassions where some interventions could be a worse option than leaving an oil spill alone. In many places, ocean microbes have developed to eat the oil seeping naturally into the environment. These same bacteria and fungi can munch away at oil spills too – albeit relatively slowly and some more than others – but if they are impacted by chemicals, such as those in dispersants, this process could be disrupted.

Bioremediation – such as adding nutrients to encourage oil-degrading bacteria – has a long history of use in oil spills. But scientists are still at the beginning of understanding the complex interactions between microbial communities and chemical dispersants, as well as how these interact with environmental factors like temperature and sunlight. Research, for example, has shown that sunlight levels impact oil degradation in different microbes differently.

A study published in 2024 became the first to use an advanced microbiology technique to look at these interactions. Rather than look at the DNA of microbes, as previous studies have done, the scientists examined the protein expression of microbes in waters off the coast of Florida – a technique usually only used in medical or clinical science.

Using these techniques can show far more detail than looking at DNA alone, says Sabine Matallana-Surget, an associate professor of environmental and molecular microbiology at the University of Stirling, Scotland, who led the study. If she did a similar study on humans, for example, she would be able to tell when they had lunch by tracking the enzymes involved in food digestion.

Her team found that Corexit induces a high expression of proteins involved in oxidative stress in oil-degrading bacteria. "I have never seen so many proteins involving DNA damage [and] repair, [as] when you introduce the Corexit to your microbial community," says Matallana-Surget. More sunlight also increased the toxicity of Corexit and oil in their experiment, creating a "double pill effect", she adds.

Dispersants aren't the only intervention after oil spills that have caused concern. "We have found after lengthy research that aggressive cleanup of some environments can cause more harm than the oil," says Helton. "Marshes and sheltered intertidal habitats, for example, are often treated very carefully."

The high-pressure, hot-water washing used to clean the ecologically sensitive shorelines of Prince William Sound in Alaska after the 1989 Exxon Valdez spill, for example, sterilised the beaches, inadvertently killing bacteria as well as larger animals. Research has shown that areas not cleaned by the hot water recovered faster than the treated sites.

If a spill like Deepwater Horizon happened today, says Matallana-Surget, the reaction would be completely different. "There have been huge conversations around what happened with applying tonnes of [a] chemical [where] we have no idea what's going in the environment. I think nobody in any part of the world would do that."

Ultimately, since spills are so hard to clean up, avoiding them happening in the first place remains the most important thing. "Prevention is going to be the most fruitful line of approach," says Short. "Continuing to implement safety measures and especially being vigilant." The problem is that standards are expensive to maintain, he says. If years go by without a spill, they "tend to start slipping".

Major changes have been made to US regulations governing offshore oil and gas operations, as well as advances in preventing blowouts in the first place. New performance measures and enforcement mechanisms have been introduced to improve pipeline safety. However, there are also new potential risks for oil spills: deeper drilling, ageing infrastructure, transport of new types of oil and through different routes such as the Arctic, and climate impacts like sea-level rise and more intense and frequent storms.

A report released by BP in September 2010 concluded that decisions made by "multiple companies and work teams", including BP and others, had contributed to the spill. The unprecedented costs – over $65bn (£49bn) – to BP of the Deepwater Horizon has acted as an incentive to companies maintain the vigilance to avoid future disasters, says Short. "I think that's really got a lot of attention in the industry, that this is not a trivial operating expense that you can just write off as business as usual."

BP also quickly announced $500m (£380m) for a 10 year research programme, which has been credited with galvanising advancement in oil spill science.

But while risks can be reduced, so long as oil is being produced, "you're not going to get rid of [spills]", adds Short. Oil supply is set to reach a record high this year, with the US last year producing more oil than any country ever has before. Until oil dependence begins to fall, sadly the risks of another oil spill will stay with us.

This is no golf cart. This is one of the biggest mining excavators in the world. The clawed bucket it uses for tearing at mineral-laced rock is so big that you could fit more than 3,000 footballs in it. The driver sits in a cab roughly as high up as the roof on an average two-storey British house. And the excavator's hefty caterpillar tracks alone are just shy of 3m (10ft) tall – and about as long as a London bus.

It weighs 778 tonnes in total and you might be forgiven for thinking that this beast, the PC8000-11 surface mining excavator made by Komatsu, could only run on a fossil fuel like diesel. Surely such a behemoth demands all the raw, dirty power of combustion to function? Well, there is a diesel model – but Komatsu have recently brought out an electric equivalent. And it works just the same.

"We are not sacrificing performance when you go electric," says Thomas Jordan, marketing manager at Komatsu Germany. While the diesel excavator guzzles more than 400 litres (88 gallons) of fuel per hour, according to Komatsu, the electric alternative relies instead on a chunky power cable – meaning the vehicle itself produces zero emissions.

When comparing diesel and electric versions of the excavator used by one Swedish customer, well-to-wheel emissions are 95% lower for the electric type, according to Komatsu. This customer has access to electricity from nuclear and hydro sources. Mining companies are increasingly interested in options like this, says Jordan. "We see a trend for more electrification, that's definitely the case."

BBC Future Planet recently went on a hunt for some of the biggest electric vehicles in the world – by size and weight. There is no shortage of impressive examples, from giant mining machines to trains and cargo ships.

Bigger electric excavators than the PC8000-11 exist, but Komatsu's vehicle is worth noting for the particularly tough job it does, stresses Jordan. The excavator's hydraulics system allows it to tackle rock – in this class of machinery, the PC8000-11 was the biggest we could find in terms of tonnage. "If you go to the big copper mines and gold mines, you will find hard material where you need that kind of hydraulic excavator," says Jordan.

For a larger electric excavator still, consider one of the biggest vehicles ever built, regardless of fuel type. It holds the Guinness World Record for heaviest land vehicle and it's not even new, having been manufactured way back in the 1990s by the German mining equipment firm Takraf. The colossal Bagger 293 bucket-wheel excavator is used for strip-mining operations in Germany and it weighs a barely believable 14,200 tonnes. That's about the same as 78 empty Boeing 747-400s.

Although the Bagger 293 dwarfs the PC8000-11 in raw tonnage, its job is a little less intense – moving earth and soil instead of rock. Nevertheless, the Bagger 293 requires so much energy that, just like the PC8000-11, it is connected to an electric power source by a cable, rather than using an on-board battery.

Ironically, the adoption of electric vehicles in mining has been going on for decades partly because coal mines tend to have their own small power plants, says Jordan. It means they can power electric vehicles on-site at a low cost – albeit using a very polluting power source.

Today, many different kinds of mines are turning to electric vehicles as a way of reducing carbon emissions from their operations. Some mines now even claim to run their machinery largely on renewable electricity. However, reducing emissions from operations only gets you so far – when it comes to coal mining, for instance, the climate-warming emissions from burning its products aren't reduced at all by electrifying the equipment used for extraction.

Mining remains a polluting and dangerous activity in many parts of the world. Globally, extractive industries, including mining, cause an estimated €400bn to €5tn ($440bn to $5.5tn/£340bn to £4.3tn) in environmental damage each year by one estimate. That's even before products such as fossil fuels are burned. But mining is also important for the extraction of minerals such as nickel, copper and gold, which can be used in consumer electronics, solar panels and, yes, electric vehicles.

"For large mining countries like Chile and Australia, they are all looking to the potential to electrify their mining industry," says Zhenying Shao, senior researcher at the International Council on Clean Transportation. She and colleagues have interviewed mine workers who recently started using electric trucks and excavators. Their comments tend to be positive – particularly about the reduction in air pollution and noise made by the vehicles, she says. "They're the ones who drive those machines, [so] that really counts."

Komatsu notes that there are limitations to cable-powered vehicles. The PC8000-11's electric cable is 300m (980ft) long. It's a considerable range, but when the excavator needs to go somewhere else, a small electrical sub-station also has to be relocated in order to power it.

Outside of mining, there are plenty of other examples of mighty electric vehicles. How much they are capable of dragging behind them can matter for certain applications, as well as their own size and weight. Take the Iveco electric van that, although not large itself, managed to tow 153.58 tonnes. The towed load comprised of a lorry carrying a digger, a truck filled with rocks and an airport fire engine all strung together, one behind the other.

But in terms of weight, heavy goods vehicles are among the largest EVs you might yourself sharing the road with. Volvo's FH Electric truck, if you include its double trailer and load, is among contenders for the heaviest battery-powered electric road vehicle. One currently being trialled in Gothenburg, Sweden, features a 74 tonne, 13m-long (43ft) version of this truck and trailer system. "They are running in commercial traffic every day," says Niklas Andersson, director of electric solutions at Volvo Trucks of the tests.

A slightly lighter, 68-tonne version of this setup is also running in Finland on a 160km (99 mile) route. Although the truck's battery can usually power the vehicle across that entire distance without requiring a recharge, weather conditions can affect performance, says Andersson. "When it's cold you have like 10cm [4in] of slush on the road, which means that the rolling resistance is really bad. Then we have to charge during the way."

He notes that the batteries for these trucks have become rapidly more energy-dense over time. The first version of the battery launched by Volvo Trucks in 2019 weighed about 500kg (1,100lb) and offered 49 kWh of energy. Last year, the company came up with a new battery that is roughly the same size and weight but offers nearly twice as much power – 94 kWh, says Andersson.

The rate of improvement of electric vehicle batteries in recent years has surprised Chris Thorne, director of strategy and operations at UMAS, a maritime consultancy, and advises on various power sources for marine industries.

"In 2015, I'm pretty sure at some point I said heavy goods vehicles will never be battery electric and five years later I was working on it. It taught me a hard lesson," he jokes. Electric drivetrains are actually well-suited to heavy duty machines because they don't require the system of shafts and gears used in petrol and diesel vehicles – these can require higher maintenance over time.

"You have a lot of flexibility in how you lay the vehicle out. You can have a motor on each wheel if you want to," adds Thorne. And he points out that batteries are helpfully modular. You can just keep adding modules until you get the amount of power you need.

There are practical limits, of course. Something as large as the PC8000-11, for example, can't run on a battery yet because, with today's technology, the battery pack would weigh more than half as much as the vehicle itself, according to Komatsu.

Energy density, the amount of power you can pack into a given volume, is still a barrier for electrifying some vehicles – notably, large aircraft. Though research suggests we might one day see electric passenger aircraft capable of carrying as many as 90 people. The biggest electric planes today can accommodate a maximum of around nine passengers.

The energy density problem also limits electrification of ships, though some surprisingly hefty vessels are beginning to run on battery power. In Incat Tasmania, an Australian shipyard, a ferry currently known as Incat Hull 096, is under construction. When complete, it is planned to have capacity for 2,100 passengers and 225 vehicles – and will be 130m (427ft) long. It was ordered by a Uruguay-based ferry operator.

Finally, the most powerful electric train in the world is perhaps the Shen24 in China. It is capable of carrying more than 10,000 tonnes – of coal – at up to 120km/h (75 mph).

Thorne notes that it isn't really surprising that electric vehicles are becoming so common in heavy industry. These machines have long service lives, tough jobs and cost a lot to buy upfront. So if you can make them cheap to run, say on locally-sourced renewable electricity, and easier to maintain with fewer moving parts than the fossil-fuel-powered alternatives, then they soon become attractive.

On the other hand, not every company or industry is ready to embrace these vehicles just yet. There may be questions over the safety of giant batteries in certain contexts where vehicles might be involved in collisions, for example. Shao says that, while heavy-duty battery electric vehicles are clearly highly capable, some companies may still hesitate about switching to them.

"It's a new technology," she says. "The industry has been dominated by diesel for so long."

Lakshmi spends several hours each day digging out large lumpy and hairy yam tubers, starchy roots that grow below the soil.

Some weigh an unwieldy 5kg (11lb) and are 4.5ft-long (1.4m), almost as tall as she is. It's painstaking work, says 58-year-old Lakshmi, who goes by one name.

First, she has to cut out the thick shoot above the ground. Then, she uses shovels to dig up the earth around the buried stem and a paddle-like flat chisel to gently pry out the tuber. She uses her hands to dig the tuber out of the ground to avoid damaging its delicate roots. When the tuber finally emerges from the ground, it is the colour of the earth, and holds the promise of spring, she says.

Lakshmi, who lives in the Wayanad district in the southern Indian state of Kerala, isn't working alone. She's part of an all-women group called Noorang, short for Nuru kilangu, a popular local variety of tuber.

The Noorang members all belong to one of Kerala's oldest indigenous tribes, the Vetta Kuruman, a nomadic community of hunters and food gatherers. They are on a mission to save the kilangu, which means "tuber" in Betta kurumba language, a mix of the South Indian languages of Kannada and Malayalam. These ancient tubers have grown on their land for centuries.

As a child, Lakshmi foraged for food in the forests, gathering edible roots, leaves, honey and fruit." [The kilangu] at the time, was a substantial meal in itself and there were so many varieties that we never got bored," says Lakshmi. "We would have different kinds of yams and sweet potatoes for at least one meal a day. My family would eat it boiled, steamed and roasted. It's a vital part of my childhood memories."

But tubers are no longer a dietary staple among tribal communities in Kerala due to their rapidly changing lifestyle and eating habits. Younger people who have ready access to a wide variety of other foods, especially rice and wheat, no longer consider the tubers that once nourished their ancestors as anything special, says TV Sai Krishnan, the coordinator of the Thirunelly Tribal Comprehensive Development Project in Wayanad, which focuses on the wellbeing of tribal people in the state.

Extreme weather has also destroyed tuber harvests in recent years. Although the tubers are fairly resilient to heat, Wayanad's frequent flooding and deadly landslides, an annual occurrence since 2019, have caused many waterlogged crops to rot.

Between 2005 and 2015, there was a steep decline in lands dedicated to tuber production in Kerala, with many of these being diverted to the more lucrative rubber cultivation instead, according to a report by the Central Tuber Crop Research Institute of Kerala.

Conserving these tubers, most of which are roughly 2-3ft long (60-90cm), isn't just an endeavour to preserve old ways and habits, it's also about boosting nutrition, says V Shakeela, director of the Community Agrobiodiversity Centre of MS Swaminathan Research Foundation, based in Wayanad.

"It's the solution to many mounting problems that these tribal communities are facing in the present, especially malnutrition and providing food security in the face of [worsening] climate change," says Shakeela. National data shows that the health of indigenous people is significantly poorer than other groups.

"Primarily, the women growing these tubers are doing so to nourish their own families, and to ensure that these ancient rare varieties don't fade away," Shakeela says.

Women in her community have always taken the lead in gathering tubers, Lakshmi says. They didn't have to venture too far into the forests to find them, and they were easy to stack and store, providing plenty of food for a growing family.

"We believe in the medicinal value of these indigenous tubers," says Shantha, another member of the Noorang group. "Most mothers here will swear by its ability to cure digestive and stomach problems, especially if you cook it with turmeric."

The Vetta Kuruman community once lived in small scattered settlements deep in the forests of Wayanad, which were vulnerable to floods and landslides.

In 2003, the community of roughly 700 people was resettled by the Keralan government and made their new homes on the outskirts of the forests in which they once lived.   

In 2016, the government gave each family half an acre of land to use how they saw fit – with the majority using it for agriculture and raising cattle. That change marked a distinct shift in dietary habits for the tribal communities, says Sai Krishnan.

The Thirunelly Tribal Comprehensive Development Project founded the Noorang group during the Covid-19 pandemic, in May 2022, with the aim of improving food security for tribal communities and to deal with their shift away from foraging tubers in the forests to cultivating rice, banana, vegetables and other crops on their lands.

The project is part of the Kudumbashree Mission in Kerala (kudumbashree means "the prosperity of family" in the local Malayalam language), a government farming initiative to eradicate poverty, provide agricultural training and empower women in vulnerable tribal communities.

"During Covid-19, we conducted an educational programme for the children of tribal members. We mapped the food they ate, and that's when we learned that many of them weren't really aware of the rich tuber varieties that once used to be the mainstay of their communities," says Saikrishnan.

The survey showed that dietary habits were changing, he says. Children showed a preference for rice, which the state government provides free to low-income families through a public distribution system.

"Tubers were always a quick, rich source of protein for us in the past," says Lakshmi. "If our children were to move away from our traditional source of food, that would be a great loss indeed. Losing the nutrition that we have relied on for generations would be like losing part of our identity."

Since their formation in 2022, the 10 members of the Noorang group have planted and brought back to the community 180 varieties of wild tubers, including 15 varieties of wild yam (noorang), three varieties of elephant yam, eight types of Colocasia (also known as elephant ears, a potato-like tuber), 16 species of turmeric, four kinds of tapioca, seven varieties of sweet potato, two of ginger, three of arrow root and one Chinese potato.

"The goal is to save as many varieties of rare seeds that we can find and to cultivate and nurture more tubers," says Sarasu, a member of Noorang.

When they first began clearing the land for planting, they faced a Herculean task, says Sarasu, because they couldn't afford to hire labour and many the thorny scrubs and plants that dotted the land, including invasive species like Lantana camera. This scrambling shrub can grow 2-4m (6.6-13.1ft) tall and forms dense thickets, full of sharp, thorny prickles.

"Our hands would bleed at the end of a day clearing… [they were] all raw and sore," says Sarasu. "We do everything ourselves, without the help of tractors that big farmers use. And we cannot afford to pay for help yet." Inadequate funds have also hampered their own efforts, she says.

The Noorang group operates on a tight budget. The land is provided by Noorang member Shantha's family and is leased to the other members for five years. In return, the other women pay her a sum of 5,000 rupees per year, which works out to roughly 3.5% of the collective's 150,000-rupee yearly revenue (£1,400/$1,800).

In addition to foraging for wild tuber seeds in the forest, members are also using seeds provided by local farmers for free, who have been eager to help them. 

"The tubers must be planted during the peak summer months in April and May before the monsoons set in so that the crop can benefit the most from the rainy weather. The harvest season is from December to March," says Sai Krishnan. 

The tubers the women have collected and sown have grown rapidly. The women take turns weeding the land on alternate days, while juggling their role as wives and mothers, caring for poultry and doing odd jobs to earn extra income.

"We need to keep up paying work as well, so we have enough income for our families,” says Sarasu. "In spite of the hardships, growing tubers is something we do for ourselves, regardless of how little we receive from it. To me, it's like embracing a part of our heritage."  

The women sell their produce in local markets themselves, and at fairs across Kerala, with each earning an average of 9,000-15,000 rupees (£80/$107) a year. "Since we cannot pay for [agricultural] labour, there are limitations to how much we can produce at the moment," says Lakshmi.

The women face other challenges as well. Monkeys and wild boars tend to snack on their produce. Wild elephants cause great damage to crops as well.

While tubers are hardy crops, resistant to heat and don't require too much water, the women say floods and landslides pose a threat to these crops. While flooding is a problem during the monsoons, severe drought in the summer months can be just as damaging.  The lack of water can impact the development of the tuber, causing it to shrivel up and shrink, affecting the quality of the crop.

At the beginning of every year, during the harvest festival called Thiragali, the women display their produce at the Thirunelly Seed Festival, alongside many other farmers who showcase their own climate-resistant seeds and farm produce. "Interacting with a wider community of farmers has always given us new insights and inspiration," says Shantha. "It makes us feel that we aren't working alone, in isolation. Knowing that the work we do is important and useful, that's kept us going."

Locally, their labour has not gone unrecognised. During the harvest festival, local authorities come to see their tubers and survey their agricultural practices, says Sarasu. Sometimes, the women have the opportunity to meet other farmers or interact with foreign tourists who sample their tubers. "This interaction and exchange of ideas has been so empowering," says Sarasu. But there's another reason why the women persevere.

"We think of our project as something special that we're doing for the next generation," says Shantha. "And that's what makes it so meaningful."

There have been a huge number of deadly weather events in 2024. Floods, heatwaves, droughts, storms and wildfires have wreaked havoc on climate vulnerable countries including India, Brazil, Nigeria, the Philippines, and through much of West and Central Africa, claiming lives and destroying homes and livelihoods.

Climate change is making severe events more frequent. Another country to face huge climate damage in recent years: Pakistan. In August 2022, the country was devastated by catastrophic flooding.

The unprecedented monsoon rains killed more than 1,500 people and left the inundated country with economic damages exceeding $30bn (£27bn). Within a month, a scientific study had concluded the high rainfall was "likely increased" by climate change.

The link between greenhouse gas emissions and extreme weather events already happening today is now well established. Events such as Pakistan's floods, Madagascar cyclones  and Somalia's drought are becoming more intense and more frequent due to climate change. They have led to death and destruction and left countries facing immense economic damages, plunging them into debt and diverting funds away from other critical areas, such as healthcare and education.

What's more, these impacts are only set to get worse. If global temperatures were to rise by 2.9C, the average GDP of the world's 65 most climate-vulnerable countries will fall by 20% by 2050 and 64% by 2100.

The discussion of who should pay for climate losses and damages has become a major geopolitical issue and is expected to be high on the agenda at the upcoming Cop27 climate talks in Sharm el-Sheikh, Egypt, in November.

By 2030, vulnerable nations are likely to face $290-580bn (£260-520bn) in annual climate "residual damages" – damages that cannot be prevented with measures to adapt to climate threats. By 2050, the total cost of loss and damage could rise to $1-1.8tn (£890bn-1.6tn).

UN Secretary General Antonio Guterres, who has become increasingly more outspoken on the injustices of climate change in recent years, has described the climate crisis as a "case study in moral and economic justice". He argues "polluters must pay" because "vulnerable countries need meaningful action."

As such climate threats become a larger part of our lives, many argue that the countries and companies responsible for the pollution in the first place should be the ones footing bill.

So what if we lived in a world where polluters really did pay for the climate damage they have caused? How much would they need to cough up, and would these payouts signal the end of the fossil fuel industry? Would this funding ever be able to alleviate the harm done? And could it mean the world's most vulnerable countries recover from climate disasters and adapt to looming threats?

Responsibility for climate change can be seen on several different levels – the actions of governments, companies, communities and individuals can all be linked to emissions.

A study published earlier this year by Dartmouth College in New Hampshire, in the US, provided the first assessment of countries' liability in fuelling the climate crisis. It concluded that emissions from the US, the world's largest historical emitter, cost the world more than $1.9tn (£1.6tn) in climate damages between 1990 and 2014. The next four largest emitters – China, Russia, India and Brazil – caused a further $4.1tn (£3.6tn) in global economic losses in the same time period. Combined, these losses are equivalent to around 11% of yearly global GDP.

"We show that there is a scientific basis for [climate] liability claims," says Justin Mankin, co-author of the study and assistant professor of geography at Dartmouth College. "The science shows that if one country can have detectable damages; one country's foregoing [of] emissions can have detectable benefits. That's really essential… it overturns this narrative of 'what can one country do?'"

If governments were serious about covering the damage from this harm, countries could establish a loss and damage finance facility under the UN Framework Convention on Climate Change (UNFCCC) – the UN's climate change body – which they would pay into in line with their fair share, says Sadie DeCoste, an organiser for Tipping Point UK, a non-profit working on climate justice. The fair share could be calculated based on their historical and ongoing contribution to global emissions, she says.

Having the fund as part of the UNFCCC process, rather than an external body, would help it to be "accountable and transparent" and ensure it is a "collective commitment to reach an agreed-upon sum", adds DeCoste. Such a fund should not be based on voluntary commitments made only by the countries that are more willing to pay, she says.

The world's most climate-vulnerable nations have called for such a facility to be set up, which would assess countries' needs after a climate disaster and request specific funds from governments based on factors including their contribution to global heating. To date, rich countries have strongly resisted these calls, insisting that humanitarian aid is enough to deal with the issue.

Fossil fuel companies are also increasingly being held accountable for their greenhouse gas emissions. A 2017 report from the CDP, a non-profit, found just 100 fossil fuel companies are responsible for producing 71% of all global greenhouse gases emitted since 1988. Another report from consultancy Profundo and non-profit Transport and Environment concluded that Europe's five biggest oil majors are responsible for some $13tn (£11.5tn) of damage in the past 30 years, including pollution, deteriorating public health and carbon emissions. These companies make enormous profits from extracting and selling fossil fuels, which have fuelled rising temperatures and exacerbated extreme weather events.

If the world's biggest fossil fuel companies were held accountable for these emissions, they could be forced to pay an annual sum, based on their share of global carbon pollution that has been emitted over the past 20 years, into a polluters-pay climate fund. This could help developing countries deal with climate impacts and the costs of transitioning to clean energy.

Polluters could also be made to pay for any ongoing emissions via an international tax on fossil fuel extraction, as proposed by a coalition of climate vulnerable nations. Here, companies would be taxed for each tonne of coal, oil or gas they extract. Starting at a low rate and increasing every year, such a tax could raise billions to help countries rebuild and recover from disasters.

"[A climate damages tax] is a way of establishing accountability and responsibility," says DeCoste. It opens up a conversation about how polluters can provide vulnerable countries with enough funding to adapt to the climate threats they are facing, she says.  

Some governments today are already considering taxing the windfall profits of fossil fuel companies that benefit from high energy prices. Some of the revenues raised by such a tax could help vulnerable communities recover from extreme events, such as droughts and floods. However, a major limitation of this in the long run is that windfall taxes on fossil fuel companies are only intended to be temporary. "We need to ensure fossil fuel companies are taxed effectively and consistently all the time, not just with one-off windfall taxes," says Olivia Hanks, climate justice lead at the faith group Quakers in Britain.

However, since governments also need to set a timeline for rapid phaseout of coal, oil and gas, fossil fuel taxes could only fund climate losses and damages temporarily, says Hanks – meaning other sources of finance will also be needed to pay for climate damages.

Industries which use a lot of fossil fuels, such as aviation and bunker shipping, could also be taxed to generate the necessary funds to pay for those suffering the impacts of climate change. Unsustainable behaviours, such as frequent flying and eating red meat, could also be taxed to raise finance for countries devastated by climate change, says DeCoste. The most polluting behaviours tend to be associated with the lifestyle of a small numbers of people with very high incomes – just 1% of the global population is responsible for 50% of flying emissions, for example, while 90% of people have never flown.

Airline travel levies, which would increase with each additional flight the individual takes, are a "fair, feasible, and suitable" way to raise loss and damage funds, some researchers say. They could generate up to $5-10bn (£4-9bn) each year, be easily collected at international flight departures, and be channelled to vulnerable communities through international bodies like the Green Climate Fund, which was set up to help developing countries reduce their emissions and adapt to climate impacts.

Redirecting public money which currently supports polluting activities towards supporting those suffering the impacts of climate change could also make a huge difference. A recent report estimated that governments around the world currently spend a staggering $1.9tn (£1.3tn) each year on environmentally harmful subsidies, such as support for fossil fuel production and for intensive agriculture. This is equivalent to around 2% of annual global GDP – money that in many cases could instead be used to support victims of climate disasters.

Governments would play an important role in redistributing money in these ways, but the courts are another important avenue through which victims of climate disasters could compensated. Recent advances in the science of "climate attribution" are especially important here.

"Climate attribution allows us to quantify the contributions of particular fossil fuel producers on impacts such as global average temperature increase, sea level rise, and ocean acidification," says Kathy Mulvey, climate accountability campaign director at the Union of Concerned Scientists in the US.

Ongoing scientific advances in this area will enable lawyers to bring more cases against polluters, says Richard Wiles, president of the Center for Climate Integrity, an advocacy organisation in the US that works to hold polluters accountable. (Read more about why climate lawsuits are surging).

One 2014 study has been particularly influential in bringing more court cases against polluters, says Wiles. The study, written by Richard Heede from the Climate Accountability Institute, established a causal link between the actions of fossil fuel companies and climate impacts. It identified 90 fossil fuel and cement producers, dubbed the "carbon majors", as being collectively responsible for 63% of global emissions since the industrial revolution, and pinpointed the share of emissions each of these companies are responsible for.

"This was critical to getting [legal] cases off the ground," says Wiles. "[As a lawyer], you needed to be able to say that Exxon was responsible for a portion of those damages with data and that the company you're accusing of crimes can actually be proven to have contributed to the damage."

A spokesperson for ExxonMobil says the company has "long acknowledged the reality and risks of climate change and has devoted significant resources to addressing those risks."

"We have announced our ambition to achieve net zero greenhouse gas emissions for operated assets by 2050," he says, adding that the company is developing roadmaps for reducing emissions from its facilities and assets.

An important case which aims to use attribution science to sue for climate damages is a lawsuit brought by a Peruvian farmer against Germany's largest utility company, RWE. The lawsuit is the first case of its kind and could set a precedent for whether polluters should provide compensation for climate damages on a pro rata basis.

In the case, which is ongoing, farmer Saúl Luciano Lliuya aims to hold RWE accountable for the role of its emissions in melting a glacier above his hometown, Huaraz, in the Peruvian Andes. Lliuya says RWE should pay 0.47% of the cost of building flood defences to protect Huaraz – which would amount to around €20,000 (£17,600;, $19,600). The amount is based on an update to Heede's study by the Climate Accountability Institute which attributes this share of global emissions to RWE.

Lliuya's lawyers are building their case on climate attribution science, including a 2021 study which concluded that the melting of the Palcaraju glacier is "entirely attributable" to rising temperatures and that the change geometry of the glacial lake and valley has "substantially increased the outburst flood hazard".

"We have a very clear picture of climate change being responsible for creating this very large lake that now threatens a city," says Rupert Stuart-Smith, the study's lead author and a research associate in climate science and the law at the Oxford Sustainable Law Programme.

The power of precedent "could mean that we will see more and more successful claims being brought before courts," he says. These could potentially be in jurisdictions across the globe and target a great number of companies, he adds. "If corporations with large emissions can be held responsible for their impact, then it could really be a game changer for pay action [polluters paying for climate damages] in many ways."

If court cases and taxes which made fossil fuel companies more accountable for the impact of their emissions did pile in, would this be the death knell for the industry – the end of coal, oil and gas?

It would certainly incentivise fossil fuel companies to switch to producing clean energy, such as wind and solar, instead of producing more carbon-intensive fuels, says Hanks. "If polluters knew they had to pay the full cost of their activities, we'd see the energy transition happen much faster."

Could this bankrupt fossil fuel companies? "If polluters are held responsible for the harm done as a result of their emissions, then you could be looking at vast sums of money," says Stuart-Smith. "I don't think it is unreasonable to talk about numbers in the billions of dollars. We could see payouts large enough that they would substantially impact [fossil fuel companies'] profits."

The fossil fuel industry is estimated to have made $2.8bn (£2.5bn) in profits per day over the last 50 years – $1tn (£891bn) a year and a staggering total of $52tn (£46tn). In a scenario where fossil fuel companies were asked to foot the entire bill of climate damages (projected to reach $290-580bn (£260-520bn) per year by 2030), this is equivalent to roughly 30-60% of their current annual profits.

Lawsuits can also directly impact a polluter's business model going forwards, adds Stuart-Smith. "We're seeing cases brought, for instance, challenging corporate and national emission reduction plans as inadequate," he says. A 2021 Dutch court ruling, for example, ordered Shell to reduce its emissions in line with the Paris Agreement on climate change. In November 2024, the oil giant won a landmark case after the Hague Court of Appeal overturned the earlier ruling requiring Shell to cut its carbon emissions by 45%, stating that it could not establish that the company had a "social standard of care" to reduce its emissions by any amount.

The ramifications of lawsuits go beyond any direct damages paid by the companies, says Wiles. "[The real damage] is the reputational risk and the loss of their social license." He compares this to the reputational damage the tobacco and opioid industries suffered after they were forced to disclose the health risks associated with their products and make public key documents which highlighted these. In the case of opioids, this disclosure led to hundreds of new lawsuits seeking to hold the industry accountable. This could also happen to the fossil fuel industry, Wiles notes.  

For climate-vulnerable countries, funds put forward by polluters would be a lifeline. The long-term finance would allow them to invest in resilient infrastructure protecting them from extreme events, such as hurricanes and floods, as well as slow-moving threats, such as rising seas.

The money would also enable countries to strengthen their public health systems and cover the climate-related health costs, such as waterborne diseases, which are increasing due to climate change.

It could also provide compensation for workers losing jobs in polluting industries. The global coal industry, for example, is estimated to lose 4.7 million jobs in the clean energy transition, while the mining industry is expected to lose 4 million jobs. Compensation could also support workers who have lost their jobs due to climate impacts, such as farmers and fishers, says Mulvey.

Many developing countries are heavily reliant on fossil fuels to meet their energy needs and grow their economies. "But the path to development is dirty; it's industrialisation," says Mankin.

Mankin says it is unclear whether loss and damage funding would put these countries on a cleaner path and allow them to develop and at the same time adapt to climate threats.  But Hanks says loss and damage finance would create "financial and decision-making space" for developing countries to focus on the energy transition, rather than  having to "relentlessly deal with disaster after disaster with no money to do so".

Loss and damage finance could also make a huge difference for people who have been permanently displaced due to climate change. It is estimated that by 2050 up to 216 million people will be forced to leave their homes due to climate impacts such as water scarcity, declining crop productivity and sea-level rise.

The money could also pay for the restoration of vital ecosystems, such as mangroves and coral reefs, which have been damaged or destroyed by storms and floods and can provide vital protection against climate impacts.

In a world where polluters did pay their fair share, would it be enough to compensate communities for the losses they have suffered? Wiles says no matter what is paid it will "never be enough", because many communities will continue to see climate impacts into the future.

What's more, there are some climate impacts which polluters could never pay for – because they cannot be quantified or recovered at any cost, says Mulvey. "No amount of money can compensate for some climate loss and damage: lost human lives, cultural heritage, animal and plant species, and ancestral lands are among the most profound impacts," she says. "The sovereignty of a country that has lost its physical territory [due to rising seas, for instance] can't be brought back with money."

Still, polluters paying for damages would help redress global climate injustice and recognise that those who are disproportionately harmed by climate change tend to not be the ones who are responsible for causing it.

"It would help us think differently about responsibility," says Hanks. "It's about calling out the moral wrong, [and] also imagining the world and those power relations differently."

Capitalism teaches us a competitive mindset where as a country we shouldn't give money to another country and thus risk our strategic advantage, she adds. "But it is possible to think in more cooperative terms and realise that if [vulnerable nations] are thriving it makes [rich countries] more likely to thrive."

In January 2024, Anna Wilson was sitting aboard a Gulfstream IV jet, observing a deceptively calm-looking sea of white clouds over the northern Pacific Ocean. Through her headphones, Wilson – an atmospheric scientist and extreme weather expert – could hear her colleague give a countdown. At the back of the plane, another colleague dropped slim, cylindrical instruments through a chute, into the brewing storm below them, to measure its strength as it approached the US West Coast.