This study represents the shift of policy on climate change of the current administration and will probably motivate the next one on tackling climate change.
Indeed, the threat seems to be so important that I am confident the United States will do its utmost to prevent the biggest changes to happen.
According to the article from the International Herald Tribune :
The rise in concentrations of carbon dioxide in the atmosphere from human activities is influencing climate patterns and vegetation across the United States and will significantly disrupt water supplies, agriculture, forestry and ecosystems for decades, a new U.S. government report says.
The changes are unfolding in ways that are likely to produce an uneven national map of harms and benefits, according to the report, released Tuesday and posted online at climatescience.gov.
The authors of the report and some independent experts said the main value of its projections was the level of detail and the high confidence in some conclusions. That confidence comes in part from the report’s emphasis on the next 25 to 50 years, when shifts in emissions are unlikely to make much of a difference in climate trends.
The report also reflects a recent, significant shift by the Bush administration on climate science. During Bush’s first term, administration officials worked to play down a national assessment of climate effects conducted mainly during the Clinton administration, but released in 2000.
The new report, which includes some findings that are more sobering and definitive than those in the 2000 climate report, holds the signatures of three cabinet secretaries.
According to the report, Western states will face substantial challenges because of growing demand for water and big projected drops in supplies.
From 2040 to 2060, anticipated water flows from rainfall in much of the U.S. West are likely to approach a 20 percent decrease from the average from 1901 to 1970, and are likely to be much lower in places like the fast-growing Southwest. In contrast, runoff in much of the Midwest and East is expected to increase that much or more.
(…) Corn and soybean plants are likely to grow and mature faster but will be more subject to crop failures from spikes in summer temperatures that can prevent pollination, said one of the authors, Jerry Hatfield, a plant physiologist with the U.S. Department of Agriculture, during a conference call with reporters.
David Schimel, a lead author and director of a U.S. government system of ecological monitoring stations, said in the call that mitigating emissions in the long run was still important, even though not much could be done to change the short-term climate picture.
The 203-page report, “The Effects of Climate Change on Agriculture, Land Resources, Water Resources and Biodiversity in the United States,” is a review of existing studies, including last year’s voluminous quartet of reports from the Intergovernmental Panel on Climate Change. It is part of a continuing assessment of lingering questions related to global warming that was initiated in 2003 by Bush.
The report did not evaluate how the risk faced by farmers, water managers and others might be reduced if they change practices or crop and livestock varieties to adjust to new conditions.
But several authors said that over all, the pace and nature of some of the looming changes would present big challenges in many of the country’s fastest-growing regions.