How Is Climate Change Affecting Glaciers And What Are The Consequences?

Monitoring Glaciers and Their Impact on Sea Level Rise

Glaciers are disappearing around the planet, and the questions of how scientists monitor glaciers and how these glaciers affect global sea level rise are very important for the future.

For The Big Questions, IFLScience’s podcast, we spoke to Dr Peter Davis, a physical oceanographer from the British Antarctic Survey to discuss these questions and his research on Thwaites Glacier in Antarctica.

How do you monitor the changes in ice shelves and glaciers?

• Peter Davis (PD): There are two or three different ways. The first and most indirect way is through satellite automations. Whizzing around the planet way up in space there are lots of satellites that we use to observe the ice shelves. We can look at their thickness, we can look at simple imagery of them, and see how they’re responding in time.
• Then there’s what I do – in-situ observation a.k.a. deep fieldwork. We go to the ice shelves and the glaciers and we either observe them from the surface, or we take observations of snowfall and weather. We use seismic, using sound essentially to understand the makeup and how thick they are.
• We also observe the ocean underneath. Using techniques known as hot water drilling to drill through the ice shelf, we deploy instruments in the ocean cavities underneath the floating ice shelves. These instruments let us monitor how the ocean is changing, how it’s circulating, its temperature, and how the ice shelf is melting from underneath. We use all that information to build a picture of how the ice shelves and glaciers are evolving over time.

Why is it important to understand how the glacier or ice shelf is melting from beneath?

• (PD): Essentially, the key idea is that glaciers flow in off the continent of Antarctica, like massive rivers of ice. They’re very slow moving but they drift towards the ocean and when the ice that’s on the ground gets into the ocean, it causes sea levels to rise.
• Ice shelves, which are floating extensions of these glaciers, act as a cork that holds back the ice that’s on the land. They prevent the ice from getting into the ocean and therefore they control sea level rise. The problem is when you melt an ice shelf from beneath, it weakens its ability to hold the ice back on the land and it allows the sea level rise to occur more quickly.
• When we observe an ice shelf or glacier from the surface, what we are essentially looking at is how the surface is changing. It’s basically changing its height, but that integrates a lot of different processes, of which melt is just one part. We have to make a lot of assumptions about the other processes in order to determine how much of it is melting.

What are the changes we are seeing in Antarctica that are affecting global sea level rise?

• (PD): We are seeing that warm water that is offshore of the Antarctic continent is being forced onto the continental shelves and underneath the ice shelves more rapidly. When ice shelves are in balance, the amount of ice or grounded ice that crosses over the grounding line – that’s the point where the ice shelf first starts floating – matches the amount of ice that’s lost through melting and calving of icebergs.
• The problem is that we are getting more warm water that’s coming onto the shelves; it’s driving more melting from beneath and it’s knocking ice shelves or glaciers out of balance. This means that we’re getting more ice from the land into the ocean, causing sea levels to rise.

Are there specific areas in Antarctica that are more affected than others?

• (PD): Yes, West Antarctica. Antarctica is generally split into two broad areas, East Antarctica and West Antarctica. East Antarctica is much larger, but West Antarctica is the area we are most concerned about, and this is because the warm water that’s driving the ice shelf melting gets much closer to the continental shelf in West Antarctica than it does in East Antarctica.
• In East Antarctica, for a variety of different reasons, there’s a lot of cold water on these continental shelves that essentially protects the ice shelves from the warm water that’s flowing around the continent. Currently, our best observations show that warm water isn’t readily accessing East Antarctica ice shelves. Whether that continues into the future is an open question but currently, West Antarctica is the area of most concern.

How much have things changed in West Antarctica?

• (PD): In terms of big, obvious changes, we’ve seen a number of ice shelves in the Antarctic peninsula – which is kind of the boundary between East and West – collapse entirely. The Larsen A ice shelf has gone, and the Larsen B ice shelf has gone. They’ve been collapsing from the North to the South as atmospheric temperatures warm, and then further around in the Amundsen Sea, we’re seeing warm water melting feedback. We’ve seen grounding lines retreat very rapidly, 2 kilometers (1.2 miles) a year. We’ve seen big calving events from the front of these glaciers – ice fronts have retreated inland.

Over what time period have we seen these changes?

• (PD): Probably over the last 10 to 20 years. The problem is that we see a lot of individual events and then attribution [to a particular time] is actually quite difficult, but certainly it’s been a slowly

  SDGs, Targets, and Indicators

  SDGs	Targets	Indicators
  SDG 13: Climate Action	Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters	Indicator not mentioned in the article
  	Target 13.3: Improve education, awareness-raising, and human and institutional capacity on climate change mitigation, adaptation, impact reduction, and early warning	Indicator not mentioned in the article
  	Target 13.2: Integrate climate change measures into national policies, strategies, and planning	Indicator not mentioned in the article
  SDG 14: Life Below Water	Target 14.3: Minimize and address the impacts of ocean acidification, including through enhanced scientific cooperation at all levels	Indicator not mentioned in the article
  	Target 14.5: By 2020, conserve at least 10 percent of coastal and marine areas, consistent with national and international law and based on the best available scientific information	Indicator not mentioned in the article
  	Target 14.7: By 2030, increase the economic benefits to small island developing states and least developed countries from the sustainable use of marine resources, including through sustainable management of fisheries, aquaculture, and tourism	Indicator not mentioned in the article
  SDG 15: Life on Land	Target 15.1: By 2020, ensure the conservation, restoration, and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands, mountains, and drylands, in line with obligations under international agreements	Indicator not mentioned in the article
  	Target 15.5: Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity, and protect and prevent the extinction of threatened species	Indicator not mentioned in the article
  	Target 15.9: By 2020, integrate ecosystem and biodiversity values into national and local planning, development processes, poverty reduction strategies, and accounts	Indicator not mentioned in the article

  1. Which SDGs are addressed or connected to the issues highlighted in the article?

  SDG 13: Climate Action

  The issue of disappearing glaciers and their impact on global sea level rise is directly connected to SDG 13, which focuses on climate action.

  SDG 14: Life Below Water

  The melting of glaciers and the resulting increase in sea levels have implications for marine ecosystems and the life below water, making SDG 14 relevant to the issues discussed in the article.

  SDG 15: Life on Land

  While not directly mentioned in the article, the melting of glaciers and the subsequent impact on terrestrial ecosystems and biodiversity align with SDG 15, which focuses on life on land.

  2. What specific targets under those SDGs can be identified based on the article’s content?

  Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters

  The article highlights the importance of understanding how glaciers are changing and melting, which is crucial for strengthening resilience and adaptive capacity to climate-related hazards and natural disasters such as sea level rise.

  Target 14.5: By 2020, conserve at least 10 percent of coastal and marine areas, consistent with national and international law and based on the best available scientific information

  Although not explicitly mentioned in the article, the melting of glaciers and the resulting rise in sea levels emphasize the need to protect coastal and marine areas, which aligns with Target 14.5.

  Target 15.5: Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity, and protect and prevent the extinction of threatened species

  While not directly discussed in the article, the impact of melting glaciers on terrestrial ecosystems and biodiversity highlights the urgency to take action to reduce habitat degradation, halt biodiversity loss, and protect threatened species, in line with Target 15.5.

  3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

  No specific indicators are mentioned or implied in the article that can be used to measure progress towards the identified targets.

  Behold! This splendid article springs forth from the wellspring of knowledge, shaped by a wondrous proprietary AI technology that delved into a vast ocean of data, illuminating the path towards the Sustainable Development Goals. Remember that all rights are reserved by SDG Investors LLC, empowering us to champion progress together.

  Source: iflscience.com

   

  

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