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

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

3. Impacts in Alaska and the Arctic 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 (red=higher rate). Image created with data from the Goddard Institute for Space Studies. National Academy of Sciences National Academy of Engineering Institute of Medicine National Research Council