A baby whitecoat harp seal is pictured after being washed up on the shore of Prince Edward Island, Canada, in this undated photo released on March 25. Scientists say that climate change has caused a retreat of sea ice, thereby reducing the areas where seals can rest between feeding on fish and mussels.
A polar bear sow and her cubs walk in Wapusk National Park in Churchill, Manitoba, Canada. Polar bears depend on ice for their survival. A US Geological Service report in 2007 estimated that climate change will cause sea-ice reduction to the extent that today’s population of about 22,000 polar bears will decrease two-thirds by the year 2050. The polar bear was listed as a threatened species in 2008 by the US Fish and Wildlife Service under the Endangered Species Act. Newscom/FILE
Adelie penguins leap out of the water in Antarctica on Nov. 9. Melting sea ice is causing a decline in the Adelie penguin population by adversely affecting their food supply. Glaciers in Antarctica have retreated almost 90 percent since 1980. Newscom
A female right whale swims at the surface of the water with her calf a few miles off the Georgia coast in 2009. Only 300 to 400 North Atlantic right whales remain in the world. Listed as endangered since the 1970s, the right whale is believed by scientists to be further threatened by variability of climate due to global warming. John Carrington/Savannah Morning News/AP/FILE
A green sea turtle is rescued on the beach at Brewster, Mass., on Nov. 25 and is being cared for at the New England Aquarium's animal care center in Quincy, Mass. Climate change affects sea turtles' reproduction with rising sea levels that affect nesting beaches, and rising temperatures that affect incubation and the sex of the eggs. Higher temperatures during incubation cause more female turtles to be born. Don Lewis/AP
Narwhals swim underwater in the Northern Territories of the Canadian Arctic. Scientists are using narwhals in Baffin Bay to measure water temperature in a global warming study by attaching tags to their horns with temperature sensors that transmit data. Newscom/FILE
A codfish reaches for food on the surface of an aquaculture cod farm in Bay Bulls, Newfoundland. Currently, the ocean temperature is at the top of the range that cods favor. Warmer waters could compromise cod fisheries. Greg Locke/Newscom/FILE
A 140-year-old lobster awaits release back into the ocean waters off the coast of Maine by PETA. In the short term, warmer waters have caused an increase in the numbers of lobsters, but scientists remain concerned about the physiological stress caused to their respiratory systems by higher water temperatures. Newscom/FILE
Melanie Stetson Freeman / The Christian Science Monitor / File
The oldest trees in a forest aren't just passively clinging to the carbon they've drawn from the atmosphere and stored as leaves and wood – they're capturing CO2 at a pace that increases with each passing year.