Lecture 9: Changes in the Arctic

• Permafrost has a lot of organic matter and ice, making decomposition slow
• Permafrost


  Ground that is permanently frozen, with organic matter and ice, making decomposition slow
• The Arctic is characterized by long cold dark winters
• Effects of melting permafrost

  • Sinkholes forming, land collapsing, trees leaning in drunken forests
• Permafrost has been frozen for thousands to hundreds of thousands of years, but is now melting
• Warmer temperatures can lead to permafrost melting, causing land instability
• Biomes in the Arctic

  • Taiga
  • Tundra
• Melting permafrost


  Causes land to become unstable
• Tundra


  The farthest north biome on land, characterized by low-growing plants and permafrost
• Permafrost is soil that is permanently frozen, containing organic matter and ice
• Taiga


  Covering a huge amount of North America and Asia, it consists of tall wintry trees in the forest
• Arctic changes

  Due to climate change, the Arctic is experiencing significant alterations
• As permafrost melts, organic carbon trapped in the ice is released, contributing to carbon dioxide emissions
• Changes in sea ice extent and seasonality in the arctic are influenced by increasing winter and summer temperatures
• Phenomenon in the taiga where trees bend and fall over due to melting permafrost, known as drunken forests
• Historically, permafrost was as hard as concrete and used as a building surface
• Methane trapped in lakes due to permafrost melting is a significant concern for greenhouse gas emissions
• Diseases and bacteria trapped in permafrost can be released as it melts, posing risks to humans and wildlife
• As permafrost melts, roads, railway ways, buildings, and infrastructure in the arctic ecosystem are affected
• Permafrost melting releases trapped gases like methane, a potent greenhouse gas
• Sea ice cover in the arctic is decreasing, concurrent with the increase in carbon dioxide concentration in the atmosphere
• Older oil pipelines in the arctic, not designed for permafrost melt, can lead to significant impacts like oil spills
• Increasing winter temperatures and summer temperatures

  Creating sea ice loss in the arctic
• Geopolitical consequences arise from increased ship traffic in the Arctic, raising questions about control of shipping lanes and territorial waters
• Increased ship traffic in ice-free Arctic waters can lead to environmental issues such as whale strikes, oil spills, and pollution
• Season stretching is occurring in the Arctic due to the lengthening of summer, leading to an expansion of the time without ice
• Loss of sea ice leads to decreased albedo, contributing to the acceleration of the earth's warming
• White surfaces reflect solar radiation, helping to keep the Arctic cold
• Sea ice loss increases ship traffic in the Arctic, impacting the environment
• Albedo


  How white a surface is, with white surfaces reflecting a lot of solar radiation
• As ice cover decreases in the Arctic

  There is more area for the wind to blow across, creating waves and breaking up sea ice
• The decrease in sea ice causes hardships for polar bears as they lose their traditional hunting grounds
• There are very few nations that control the Arctic shipping routes, leading to potential political consequences
• Increased wave heights in the Arctic

  Lead to the breaking up of sea ice and increased severity of storms and erosion on land
• An ice-free ocean increases wave heights in the Arctic
• Droughts, species extinctions, and biome shifts are also affecting the Arctic due to climate change
• Tundra ecosystems in the Arctic are shrinking due to the shifting climate, leading to biome extinction
• Coastal communities are experiencing erosion due to the lack of sea ice and the increase in wave heights
• Sea ice is used for transportation by both people and polar bears in the Arctic
• Wildfires are occurring more frequently in the Arctic, leading to ash and smoke settling on ice and snow, accelerating melting