7.1 Impacts of climate change on the Arctic

Climate change is hitting the Arctic hard, warming it twice as fast as the rest of the world. This rapid warming is causing big changes, like melting sea ice and thawing permafrost, which affect wildlife, ecosystems, and people living in the region.

These Arctic changes have global impacts too. They're messing with weather patterns, raising sea levels, and releasing more greenhouse gases. It's a vicious cycle that's speeding up climate change worldwide.

Climate Change Impacts on the Arctic

Arctic Amplification and Sea Ice Loss

• The Arctic is warming at a rate twice as fast as the global average, leading to significant changes in the region's environment (Arctic amplification)
• Sea ice loss is one of the most visible and dramatic impacts of climate change in the Arctic
  • The extent and thickness of sea ice have been declining rapidly in recent decades, with the minimum summer sea ice extent reaching record lows
  • The loss of sea ice has far-reaching consequences for Arctic ecosystems, as many species rely on sea ice for hunting (polar bears), breeding (ringed seals), and resting (walruses)
  • The reduction in sea ice alters the Earth's albedo, as open water absorbs more solar radiation than reflective ice, further amplifying warming in the region

Permafrost Thaw and Ecosystem Disruption

• Permafrost, ground that remains frozen for two or more consecutive years, is thawing due to rising temperatures in the Arctic
  • As permafrost thaws, it releases greenhouse gases, such as carbon dioxide and methane, that have been trapped in the frozen ground for thousands of years, contributing to further warming
  • Thawing permafrost can lead to ground subsidence and erosion, damaging infrastructure such as buildings, roads (Alaska Highway), and pipelines (Trans-Alaska Pipeline System)
• Climate change is causing significant disruption to Arctic ecosystems, affecting both terrestrial and marine habitats
  • Changing temperatures and precipitation patterns are altering the distribution and abundance of plant (shrubs expanding northward) and animal species (Arctic fox, caribou)
  • The timing of key ecological events, such as plant flowering and animal migration, is shifting in response to climate change, potentially leading to mismatches between species and their food sources
  • Ocean acidification, caused by the absorption of atmospheric carbon dioxide, is negatively impacting marine organisms, particularly those with calcium carbonate shells or skeletons (mollusks, corals)

Social and Economic Impacts of Arctic Climate Change

Traditional Livelihoods and Food Security

• Arctic communities, particularly Indigenous peoples, are facing significant challenges due to climate change, as their traditional ways of life and livelihoods are closely tied to the environment
• Changes in sea ice and permafrost are affecting the availability and accessibility of traditional food sources, making it more difficult for Indigenous communities to maintain their subsistence practices
  • The unpredictability of sea ice conditions makes travel and hunting more dangerous, increasing the risk of accidents and injuries
  • Reduced access to marine mammals (seals, walruses) and fish (Arctic char, salmon) threatens food security and cultural practices

Infrastructure and Economic Challenges

• Climate change is impacting the infrastructure and transportation systems of Arctic communities, as thawing permafrost and coastal erosion damage buildings, roads, and airports
  • The high costs associated with adapting to and mitigating these impacts place a significant financial burden on Arctic communities, many of which have limited economic resources
  • Relocating entire communities (Newtok, Alaska) or rebuilding infrastructure is often necessary but extremely costly
• The loss of traditional livelihoods and the need to adapt to a changing environment can lead to increased stress, mental health challenges, and social disruption within Arctic communities
  • Climate change is exacerbating existing social and economic inequalities in Arctic communities, as those with fewer resources are often the most vulnerable to its impacts

Cultural Heritage and Identity

• The cultural heritage and identity of Arctic Indigenous peoples are closely linked to their environment and traditional practices, such as hunting, fishing, and reindeer herding
  • As climate change alters the landscape and disrupts these practices, it threatens the transmission of traditional knowledge and cultural continuity across generations
  • The loss of cultural landmarks (sacred sites, burial grounds) due to coastal erosion and permafrost thaw further undermines cultural identity
• Adapting to climate change while preserving cultural traditions presents a significant challenge for Arctic Indigenous communities
  • Incorporating traditional knowledge into climate change adaptation strategies can help maintain cultural resilience and promote sustainable solutions

Global Significance of Arctic Climate Change

Impacts on Global Climate Systems

• The Arctic plays a crucial role in regulating the Earth's climate, and changes in the region have far-reaching consequences for the global climate system
• The loss of Arctic sea ice is contributing to changes in global atmospheric and oceanic circulation patterns, which can affect weather patterns and climate in other parts of the world
  • The reduced temperature gradient between the Arctic and the mid-latitudes, caused by the rapid warming of the Arctic, may be altering the behavior of the jet stream, leading to more persistent and extreme weather events (heat waves, cold spells) in the mid-latitudes
• The thawing of Arctic permafrost and the release of greenhouse gases have the potential to further amplify global warming and contribute to a positive feedback loop
  • The Arctic permafrost contains an estimated 1,400-1,600 billion tons of organic carbon, which, if released into the atmosphere, could significantly accelerate global warming

Sea Level Rise and Socioeconomic Consequences

• Changes in the Arctic can affect global sea levels, as the melting of land-based ice contributes to sea-level rise
  • The Greenland Ice Sheet, which contains enough water to raise global sea levels by approximately 7 meters (23 feet), is losing mass at an accelerating rate due to warming temperatures
  • Coastal communities worldwide (Miami, Shanghai) are vulnerable to the impacts of sea-level rise, including increased flooding, erosion, and saltwater intrusion into freshwater resources
• The global impacts of Arctic climate change have significant implications for human societies and the global economy
  • Agricultural systems may be affected by changing weather patterns, potentially impacting food production and food security
  • The increasing costs of adapting to and mitigating climate change may strain global economic resources and exacerbate existing inequalities

Drivers of Arctic Climate Change

Greenhouse Gas Emissions and Black Carbon

• Greenhouse gas emissions, primarily from human activities such as fossil fuel combustion, deforestation, and industrial processes, are the main driver of climate change in the Arctic and globally
  • The increasing atmospheric concentrations of greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), trap heat in the Earth's atmosphere, leading to warming temperatures
  • The Arctic is particularly sensitive to greenhouse gas-induced warming due to the region's unique feedback mechanisms and amplification processes
• Black carbon, or soot, from the incomplete combustion of fossil fuels and biomass, is a significant contributor to warming in the Arctic
  • When deposited on snow and ice, black carbon reduces the surface albedo, increasing the absorption of solar radiation and accelerating melting
  • Sources of black carbon include wildfires, diesel engines, and residential coal and biomass burning

Atmospheric and Oceanic Circulation Patterns

• Changes in atmospheric and oceanic circulation patterns, influenced by factors such as the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO), can affect the transport of heat and moisture into the Arctic, contributing to warming and sea ice loss
  • The AO and NAO are natural climate variability patterns that influence the strength and position of the polar jet stream and the intensity of storms in the North Atlantic
  • Positive phases of the AO and NAO are associated with increased transport of warm, moist air into the Arctic, contributing to warming and sea ice loss

Feedback Loops and Natural Variability

• Positive feedback loops, such as the ice-albedo feedback and the permafrost carbon feedback, amplify the impacts of climate change in the Arctic
  • The ice-albedo feedback occurs when the loss of reflective sea ice and snow exposes darker surfaces, such as open water and land, which absorb more solar radiation, leading to further warming and ice loss
  • The permafrost carbon feedback involves the release of greenhouse gases from thawing permafrost, which contributes to additional warming and further permafrost thaw
• While natural variability, such as variations in solar activity and volcanic eruptions, can influence Arctic climate on shorter timescales, the observed long-term warming trend and its impacts are primarily driven by human-induced greenhouse gas emissions
  • Solar activity and volcanic eruptions can cause short-term cooling or warming in the Arctic, but their effects are relatively small compared to the long-term warming trend driven by greenhouse gas emissions