Northward Species Shifts
The ranges of many plant and animal species are projected to shift northward, resulting in an increased number of species in the Arctic. Some currently widespread arctic species are likely to suffer major declines.
Impacts on Natural Systems
Wetland Changes
Permafrost thawing will cause lakes and wetlands to drain in some areas, while creating new wetlands in other places. The balance of these changes is not known, but as freshwater habitats are thus modified, major species shifts are likely.
Vegetation Shifts
Vegetation zones are projected to shift northward, with forests encroaching on tundra, and tundra encroaching on polar deserts. Limitation in amount and quality of soils are likely to slow this transition in some areas.
Increasing Fires and Insects
Forest fires, insect infestations and other disturbances are projected to increase in frequency and intensity. Such events can subject habitats to invasion by non-native species.
Marine Species at Risk
Marine species dependent on sea ice, including polar bears, ice-living seals, walrus, and some marine birds, are very likely to decline, with some species facing extinction.
Land Species at Risk
Species quite specifically adapted to the arctic climate are especialy at risk including many species of mosses and lichens, lemmings, voles, arctic fox, and snowy owl.
UV Impacts
Increased ultraviolet radiation reaching the earth's surface as a result of stratospheric ozone depletion and the reduction in spring snow and ice cover will impact ecosystems on land and in water.
Old-growth Forest Loss
Old-growth forest is rich in species of lichens, mosses, fungi, insects, woodpeckers, and birds that nest in tree cavities. Climate warming would increase forest fires and insect-caused tree death, further reducing this valuable habitat which is already declining due to other human activities.
Carbon Cycle Changes
Over time, replacement of arctic vegetation with more productive vegetation from the south is likely to increase carbon dioxide uptake. On the other hand, methane emissions, mainly from warming wetlands and thawing permafrost, are likely to increase.
Center for Environmental Education and Information
