Climate heating has reached even deepest parts of the Arctic Ocean – New Scientist

Report on Deep Arctic Ocean Warming and its Implications for Sustainable Development Goals

1.0 Introduction

Recent oceanographic analysis reveals that the deep waters of the Arctic Ocean are warming at a significant rate, a phenomenon previously underestimated. This warming, driven by processes linked to global climate change, has profound implications for environmental stability and the achievement of the United Nations Sustainable Development Goals (SDGs), particularly SDG 13 (Climate Action) and SDG 14 (Life Below Water).

2.0 Key Findings on Oceanic Warming

Data collected via icebreaker expeditions indicates a clear warming trend in the deep Arctic, challenging the assumption that these regions were insulated from climate change impacts.

• Eurasian Basin: The waters between 1500 and 2600 metres deep have warmed by 0.074°C since 1990.
• Energy Transfer: This temperature increase corresponds to an energy transfer of nearly 500 trillion megajoules, an amount sufficient to melt a significant portion of the Arctic’s minimum sea ice extent if applied to the surface.
• Greenland Basin: The source of cooling deep water has itself warmed rapidly, with temperatures rising from -1.1°C to -0.7°C, diminishing its ability to offset warming in the adjacent Arctic basin.

3.0 Causal Mechanisms of Deep Ocean Heating

The warming process is attributed to a combination of factors, with a critical disruption in the natural cooling mechanism.

1. Atlantic Water Influx: An extension of the Atlantic Meridional Overturning Circulation (AMOC) transports warmer, saltier Atlantic water into the upper layers of the Eurasian basin.
2. Sinking of Warm Water: As sea ice forms, ejected salt increases the density of the surrounding water, causing it to sink and carry heat from the Atlantic influx to the deep ocean.
3. Geothermal Heating: The Earth’s geothermal heat provides a constant source of warming from the ocean floor.
4. Reduced Cooling Effect: The primary cause for the net warming is the reduction of cold deep water flowing from the Greenland basin. The accelerated melting of the Greenland ice sheet has introduced large volumes of freshwater, slowing the formation and sinking of cold, dense water that historically balanced the heating processes.

4.0 Implications for Sustainable Development Goals (SDGs)

The warming of the deep Arctic Ocean directly impacts several SDGs, highlighting the interconnectedness of global climate systems and sustainable development.

• SDG 13: Climate Action

  The findings are a critical indicator of the far-reaching consequences of insufficient climate action. The warming serves as direct evidence that anthropogenic climate change is affecting all parts of the global climate system.

  • The potential for warming to thaw sub-sea permafrost and release methane from clathrate deposits represents a dangerous climate feedback loop that would further accelerate global warming, undermining efforts to meet climate targets.

• SDG 14: Life Below Water

  The temperature change poses a direct threat to the unique and fragile marine ecosystems of the deep Arctic, jeopardizing marine biodiversity and the health of the ocean.

  • Warming alters the fundamental physical properties of deep-sea habitats, which can disrupt marine life, food webs, and biogeochemical cycles.

• SDG 11 & SDG 15: Sustainable Cities and Communities & Life on Land

  The root cause of this phenomenon—the melting of the Greenland ice sheet—is a major contributor to global sea-level rise, which directly threatens the sustainability of coastal communities (SDG 11) and terrestrial ecosystems (SDG 15) worldwide.

5.0 Conclusion

The research confirms that the deep Arctic Ocean is an active component in the global climate system and is highly sensitive to changes originating elsewhere. This deep-sea warming could eventually contribute to further sea ice melt from below, creating a compounding effect. These findings underscore the urgent necessity for global cooperation and intensified efforts to mitigate climate change in order to protect critical planetary systems and ensure the viability of the Sustainable Development Goals.

Analysis of Sustainable Development Goals in the Article

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

• SDG 13: Climate Action

  This goal is central to the article, which explicitly discusses the impacts of climate change. The text focuses on the “warming of the Arctic Ocean” as a direct consequence of global warming, a phenomenon previously underestimated in this region. It links atmospheric warming to shrinking sea ice and now, through new research, to the heating of the deep ocean, reinforcing the urgency of climate action.

• SDG 14: Life Below Water

  The article’s subject is the health of the Arctic Ocean, a major marine ecosystem. It details how “warmer Atlantic water… is heating up the depths of the Arctic Ocean,” which directly impacts the marine environment. The discussion of changes in water temperature and circulation patterns falls squarely under the goal of conserving and sustainably using the oceans and their resources.

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

• SDG 13: Climate Action

  • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards. The article identifies a new climate-related hazard: the rapid warming of the deep Arctic Ocean. The research itself is a foundational step in understanding this hazard, which is necessary for developing resilience and adaptation strategies.
  • Target 13.2: Integrate climate change measures into national policies, strategies and planning. The findings that the “deep ocean is much more active than what we thought” and that warming could “thaw sub-sea permafrost” provide critical data that must be integrated into climate models and policies to accurately predict and mitigate future climate change.

• SDG 14: Life Below Water

  • Target 14.2: By 2020, sustainably manage and protect marine and coastal ecosystems to avoid significant adverse impacts. The article describes a significant adverse impact—deep ocean warming—on the Arctic marine ecosystem. The research highlights a “new heating process in the deep Arctic Ocean,” which underscores the need for protective measures.
  • Target 14.a: Increase scientific knowledge, develop research capacity and transfer marine technology… to improve ocean health. The entire article is based on a scientific study conducted by “researchers from the Ocean University of China” using “icebreaker ships.” This directly exemplifies the effort to increase scientific knowledge and research capacity to understand and improve ocean health.

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

• Indicators for SDG 13 (Climate Action)

  • Rate of Ocean Warming: The article provides a precise measurement: “the waters between 1500 and 2600 metres deep have warmed by 0.074°C since 1990.” It also notes the deep water temperature in the Greenland basin rose “from -1.1°C to -0.7°C.” These are direct indicators of climate change impact.
  • Extent of Sea Ice Cover: The article states that “The sea ice on top of the Arctic Ocean has shrunk by about 40 per cent in four decades.” This is a key indicator used to track the effects of global warming.
  • Rate of Ice Sheet Melt: The article implies this indicator by mentioning that “as the Greenland ice sheet melts, more freshwater has entered the Greenland basin.” Monitoring the volume of meltwater is a crucial indicator of climate change.

• Indicators for SDG 14 (Life Below Water)

  • Ocean Temperature at Various Depths: The specific temperature increase of “0.074°C” in the deep Eurasian basin is a direct indicator of changing conditions in a marine ecosystem, which affects ocean health.
  • Ocean Circulation Patterns: The article describes how the “Atlantic Meridional Overturning Circulation, or AMOC, brings warm Atlantic water northwards” and how the influx of freshwater from Greenland has “slowed the sinking of cold, salty water.” Monitoring these circulatory systems serves as an indicator of the stability of marine ecosystems.

4. Summary Table of SDGs, Targets, and Indicators

Source: newscientist.com