U.S. Environmental Impacts from Climate Change
Climate-Related Environmental Changes in the United States
Jul 21, 2009
In June 2009, the National Science and Technology Council presented a scientific report to Congress. Based on the most up to date, peer reviewed science, the report lays out in plain language the present environmental cost of global warming on the U.S. and the possible future environmental impacts of climate change. The report is titled Global Climate Change Impacts in the United States, edited by Thomas Karl, Jerry Melillo, and Thomas Peterson and published by Cambridge University Press.
Present Climate-Related Environmental Changes.
Climate change, largely due to rising carbon dioxide levels in the atmosphere, is unequivocal and is already causing environmental impacts in the United States. Some of the present effects of this man-made environmental change are:
- The United States has warmed significantly over the past half decade, with average American temperatures over 2 degrees F. warmer. On a seasonal basis, America will have greater warming in summer months, except for Alaska, which will experience greater warming in winter months.
- While overall rainfall has increased in the US, the greatest increases have been seen in the Northeast, Great Plains and parts of the Midwest. Much of the Southeast and Northwest has seen decreases in rainfall. Overall, the intensity of heavy downpours of rain has increased by over 20% in the past century.
- Destructive Atlantic hurricanes have increased both in power and frequency over the last number of decades. It is the oceans that provide hurricanes with their energy, and the temperature of the ocean in the Atlantic hurricane development region has increased by over 2 degrees F. over the last 30 years.
- Animal and plant ecosystems in the United States have been affected by climate change, mainly caused by shifting seasons, with spring now arriving on average 10 days earlier than it did 20 years ago. The distribution of species has also changed with a northward shift in range coupled with an upward shift in elevation.
While present and past environmental changes due to climate change can be measured and quantified, predicting future environmental impacts of global warming is at best an inexact science. Within that framework, while it is impossible to foretell actual future environmental events, it is possible to predict future trends. Without very deep cuts in carbon dioxide emissions the United States can expect some major environmental changes in the near future.
- Deserts and drylands will become hotter within the next half century and will expand to the northeast and also in elevation. This warming of drylands will have a knock-on effect on forest fires and the increased risk of drought will heighten water stresses and exasperate the threat of plant disease.
- Coastal and near-shore marine ecosystems are likely to become much more stressed due to rising sea levels and ocean acidification with resultant further degradation of U.S. coral reef ecosystems.
- As ocean temperatures continue to rise, so too will the intensity of hurricanes, which will tend to cause much more widespread environmental damage in addition to transportation and communications damage.
- Irrespective of the inexactitude of the science, it is now virtually certain that summer sea ice will disappear completely from the Arctic in the next few years, with disastrous environmental consequences for Alaska and the Canadian Arctic.
- The possibility of abrupt environmental changes cannot be excluded. Abrupt shifts in drought frequency and duration, rapid ice sheet melting, especially of the Greenland ice shelf, and sudden changes in the ocean currents could all have a devastating effect on various parts of the American environment.
The present U.S. administration is attempting to get a number of climate change bills through the Houses of Congress, not least among them the “Carbon Cap and Trade” legislation. These bills, designed to help mitigate climate change, will carry a high financial cost to all Americans. Global Climate Change Impacts in the United States lays out the environmental cost that Americans will pay if the United States government and people baulk at the financial cost of combating global warming.
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