Report Outlines Impact of Climate Change on U.S.
Rising Sea Levels, Higher Temperatures, Harsher Storms, and Drought
Aug 8, 2009
Climate change has finally got the attention of those in Washington. So much so that the U.S. Global Change Research Program (USGCRP), a government program that coordinates and integrates federal research on changes to the global environment, has put together a report that focuses on the impacts of climate change in the United States and how to address those changes.
The USGCRP report - "Global Climate Change Impacts in the United States" - was written by an expert team of scientists and draws from a large body of scientific evidence. Thirteen agencies and departments participate in the USGCRP, with the National Oceanic and Atmospheric Administration (NOAA) serving as the lead agency. NOAA and the other agencies approved the report after it was extensively reviewed and revised based on feedback from the experts and the public.
Changing Climate in the U.S.
Since 1900, the average global temperature has risen by about 1.5 degrees (Fahrenheit). By 2100, the average temperature is projected to rise another 2 to 11.5 degrees. The U.S. has kept pace with this change and will likely continue to do so, although the increase could vary from region to region.
The consequences of the warmer temperatures can already be seen in the United States. Not surprisingly, air and water temperatures have risen, which has, according to the report, resulted in "reduced frost days, increased frequency and intensity of heavy downpours, a rise in sea level, and reduced snow cover, glaciers, permafrost, and sea ice."
Scientists have also observed longer growing seasons and ice-free periods on rivers and lakes, as well as an increase in atmospheric water vapor. In fact, over the last 30 years, the average winter temperatures in the Midwest and northern Great Plains regions of the U.S. have increased more than 7 degrees. And some changes are occurring much quicker than previously estimated.
As temperatures continue to rise, these climate-related changes will also continue, and new types of changes will develop. For example, the Southwest is likely to see drier conditions, while the southeast coastal regions could experience more intense hurricanes. According to the report, the current and future changes will affect "human health, water supply, agriculture, coastal areas, and many other aspects of society and the natural environment."
Mitigating the Impact of Climate Change
Although the USGCRP report focuses on current and future climate changes, it also outlines actions that the U.S. can take to respond to these changes. These actions can be divided into two categories: mitigation and adaptation.
Mitigation refers to actions that limit further climate change. Reducing carbon dioxide is the primary focus of the mitigation strategies. This is because carbon dioxide emitted into the atmosphere as a result of human activity is considered one of the primary causes of global warming.
Scientists believe that, in order to limit the extent of climate-related changes, steps should be taken to reduce carbon dioxide emissions, such as improving energy efficiency, using energy that doesn't produce carbon dioxide (or minimizes its production), and capturing carbon dioxide produced through the use of fossil fuels.
"Over the long term, lower emissions will lesson both the magnitude of climate-change impacts and the rate at which they appear." The smaller the changes and the slower they come, the easier they are to adapt to.
Adapting to Climate Change
Even if heat-trapping emissions were eliminated, climate change will continue because carbon dioxide and other gases have already been released into the atmosphere. Scientists expect some gas levels to remain elevated for hundreds of years or more. In addition, the world's oceans will retain the heat they've absorbed for many decades. As a result, the U.S. will need to adapt to the changes.
The USGCRP report offers a number of strategies for adapting to climate change. For example, companies might relocate away from coastal areas susceptible to hurricanes and rising sea levels. Farmers might grow crops better suited to warmer or drier conditions. Communities might alter zoning and building codes to minimize vulnerability to fires or floods.
The challenge to adapting to climate change, however, is that it is an unpredictable target. Although humans have adapted to climate changes in the past, those changes came at a rate much slower than what the U.S. faces in the coming decades.
In addition, the country is part of an increasingly interdependent world. "For example, conflicts or mass migrations of people resulting from food scarcity and other resource limits, health impacts, or environmental stresses in other parts of the world could threaten U.S. national security."
Clearly, the U.S. is not in this alone, and any adaption strategies - or mitigation strategies for that matter - must factor in other parts of the globe. Unfortunately, the USGCRP report doesn't include this sort of global analysis, but it does acknowledge the importance of taking into account climate change outside the United States. And that, at least, is a start.
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