Click here to check out CBSNews.com's report on the study, which was commissioned by Congress to find out, region by region, what kinds of environmental changes might happen if the earth warms by between 5 and 10 degrees, as some scientists predict.
Here are some of the predictions in the study, which is expected to be made public next week:
Rising sea levels and more frequent storm surges threaten coastal development. Some coastal wetlands, barrier islands and beaches will disappear. Variety of tree species will increase, but many forests will be displaced by grassland and savannas. Increase in water quality problems.
Warming will ease winter weather extremes, but bring more rain and possible flooding. Warming may exacerbate pollution from agricultural runoff in places like the Chesapeake Bay. Hotter summers likely, with more frequent and intense heat waves especially affecting cities. Forest species shift northward and maple trees may disappear. Some coastal urban centers may have to rework sewer, water and transportation systems because of sea level rise. Mountain regions see decline in skiing and increase in other activities such as hiking.
Great Lakes States
Water levels likely to decline because of increased evaporation, leading to reduced water supply. Shoreline damage likely to decrease, but lower water levels add to marine transportation problems. Cities along lakes must adapt to new water levels.
Midwestern-Great Plains States
Increased stress in major cities because of extreme summer heat, but winters will become milder, reducing winter-related illnesses and deaths. Longer growing season and increases in carbon dioxide will cause higher crop yields and allow planting of more types of crops and in many cases more than one crop a year. Despite higher rainfall, warmer weather will increase evaporation, reducing lake and river water levels. Likelihood of more droughts and flash flooding. Farming on marginal land will become more difficult.
Western and Mountain States
Warmer winter temperatures will reduce snow accumulations in mountains, reducing summer runoff and complicating water management, flood control and irrigation. Higher elevation ecosystem will shift with parts of the mountain region becoming drier. Alpine meadows in the Rocky Mountains are likely to face extreme stress and may disappear.
Increased moisture will result in decline of desert ecosystem, while shrublands expand. Increase in crop diversity. Areas may have a variation of wet and dry periods adding to flooding and fire risks. Some birds and mammals may shift to higher elevations, while reptiles and amphibians ay move to lower elevations with warming. Changes in mountain snowpack will require changes in water management.
Northwestern States and Alaska
Warmer water temperatures may cause some fish species, including Pacific Northwest salmon, to migrate northward. Warmer water species may move into Northwest. Warmer weather likely to increase rainfall in summer and cause changes in species mix. Sea level rise will impact low-lying areas, especially in Puget Sound area. Warming in Alaska will increase permafrost thawing, resulting in damage to roads, buildings and impacting forests.
Sea level rise and increased possibility of storms will impact island areas, including Hawaii. This may reduce availability of fresh water and in some cases pose health risks. Higher water temperatures and increased carbon dioxide levels likely to exacerbate coral bleaching and increase destruction of coral reefs off southern Florida and Hawaii Islands.
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