Habitats

Wildlife depends on healthy habitats. They need the right temperatures, fresh water, food sources, and places to raise their young. Climate change is altering key habitat elements that are critical to wildlife's survival and putting natural resources in jeopardy.

Temperature: Melting Arctic ice removes hunting ground from polar bears. Warmer water temperatures will cause population declines for trout, salmon, and many other species that require cold water to survive. Rising ocean temperatures have already caused massive coral bleaching, leading to the collapse of these ecosystems, which sustain huge numbers of fish. Coral bleaching occurs when colorful algae that live in corals die or are expelled from corals under stress. The algae live symbiotically with coral polyps, providing them with nutrients and oxygen. If the algae die and are not replaced, the corals will also die.

Many species take their cues about when to migrate, flower, nest, or mate from seasonal changes in temperature, precipitation, and daylight. Climate change is confusing those signals and forcing wildlife to alter their life cycle and seasonal events. In the western United States, warming and drought stress are causing trees to die and making them more vulnerable to pine beetle and other insect infestations. Higher temperatures and increased fuel from dead trees have led to more wildfires.

Water: Larger floods are expected to increase erosion levels, reducing water quality and degrading aquatic habitat. Severe droughts stress and can kill plants on which wildlife depend for food and shelter, and deprives wildlife of water sources.

Food: Some animals are laying eggs, migrating, or emerging from hibernation much earlier than they used to, only to find that the plants or the insects they need for food have not yet emerged. Climate change has altered food availability for migratory species; birds arrive on schedule to find that their food sources—insects, seeds, flowering plants—have hatched or bloomed too early or not at all. Milder winters cause seasonal food caches to spoil, so wildlife species like the gray jay depending on food stores to survive the winter are left without sustenance.

Places to raise young: Droughts caused by climate change could dry up 90 percent of central U.S. wetlands, eliminating essential breeding habitat for ducks, geese, and other migratory species. Rising sea level and changes in salinity could decimate mangrove forests, leaving many fish, shellfish, and other wildlife without a place to breed, feed, or raise offspring.

Often overlooked, just as important as the many ways in which our climate is changing, is that it is changing so fast and thus the urgent need to address climate change. Species may not be able to adapt to rapid climate change or to move fast enough to more suitable areas as their current habitats become less suitable for them. Unless significant action is taken now, climate change will likely become the single most important factor to affect wildlife since the emergence of mankind.

Our country is home to a diverse array of wildlife ranging from the highest peaks, to the driest deserts, to freshwater and marine environments, and to all the places in between. These abundant and diverse wildlife resources, which are so important to our culture and well-being, face a bleak future if we don't address climate change.

• Estuaries and Coastal Wetlands
• Coral Reefs
• Eastern Hemlock Forests
• Mangroves
• Sagebrush Steppe
• Southwestern Streams
• Western Forests
• Southern Forests