Impacts in Alaska and the Arctic

1
Impacts in Alaska and the Arctic
National Academy of Sciences National Academy of
Engineering Institute of Medicine National
Research Council

• Effects on Ice-Dependent Animals
• Year-round sea ice shrinking walruses and other
  animals challenged to find platforms for nursing
  and resting
• Polar bears facing difficult hunting conditions
  seals now surfacing in open ocean instead of
  holes in ice

2
Impacts in Alaska and the Arctic
National Academy of Sciences National Academy of
Engineering Institute of Medicine National
Research Council

• Changing Food Chains
• Increased shrub growth presenting a threat to
  caribou (wild reindeer)
• Shrubs crowding out lichens (a key winter food
  for caribou)
• Shrubs collect snow, causing deep snowdrifts
  deep snow makes it hard for caribou to reach
  lichens hidden beneath

3
Impacts in Alaska and the Arctic
National Academy of Sciences National Academy of
Engineering Institute of Medicine National
Research Council

• Feedback Loops Arctic Warming Faster
• The Arctic is warming twice as fast as the rest
  of the planet
• As sea ice and seasonal snow cover melts,
  previously reflective white surfaces converted to
  darker surfaces (to ocean water or vegetation)
• Thawing permafrost releases carbon dioxide and
  methane into the atmosphere, increasing
  greenhouse gases

Rate of warming, indicated by colors (redhigher
rate).
Image created with data from the Goddard
Institute for Space Studies.