|2011年夏天，受熱浪侵襲的紐約市。圖片來源：ChrisGoldNY。（CC BY-NC 2.0）|
Global action on climate change would avoid 12,000 deaths a year from extreme temperatures in 49 U.S. cities, compared to a future with no cuts in greenhouse gas emissions, finds a new peer-reviewed risk analysis issued Monday by the U.S. Environmental Protection Agency.
“This is more than a 90 percent reduction from what we would expect with no action,” states the report, “Climate Change in the United States: Benefits of Global Action.”
“We can save tens of thousands of American lives, and hundreds of billions of dollars annually in the United States by the end of this century, but the sooner we act, the better off America and future generations of Americans will be,” said EPA Administrator Gina McCarthy.
Global action on climate change would avoid costly damages in the United States, the report concludes.
The potential future effects of global climate change include more frequent wildfires, longer periods of drought in some regions and an increase in the number, duration and intensity of tropical storms. NASA scientists say the Earth’s average temperature has increased about one degree Fahrenheit during the 20th century and global climate change has already had observable effects on the environment.
The report is timed to prepare Americans for the new universal, legally-binding climate agreement that is expected to be signed by world leaders at the UN Climate Summit in Paris in December.
Unlike the 1997 Kyoto Protocol that it will replace, the terms of the new agreement will include limits on greenhouse gas emissions from both developing and industrialized countries.
Compared to a future with unchecked climate change, climate action is projected to avoid some 13,000 U.S. deaths in 2050 and 57,000 deaths annually in 2100 from poor air quality, the study finds.
Global action now leads to greater benefits over time, but delaying action on limit emissions will likely diminish these and other benefits, the report concludes.
The CIRA project spans 20 U.S. sectors related to health, infrastructure, electricity, water resources, agriculture and forestry, and ecosystems.
The report compares two future scenarios: a future where global warming has been limited to 2 degrees Celsius (3.6 degrees Fahrenheit), and a future with no action on climate change, where global temperatures rise 9 degrees Fahrenheit.
The report then quantifies the differences in health, infrastructure and ecosystem impacts under the two scenarios, producing estimates of the costs of inaction and the benefits of reducing global greenhouse gas emissions.
For nearly all of the 20 sectors studied, global action on climate change reduces economic damages, the authors concluded.
Without climate action, for instance, they estimated up to $10 billion in increased road maintenance costs each year by the end of the century. With emissions limits, the United States can avoid up to $7 billion of these damages.
In a future without greenhouse gas limits, the report estimated damages from sea-level rise and storm surge to coastal property in the lower 48 states are $5.0 trillion dollars through 2100. With adaptation along the coast, the estimated damages and adaptation costs are reduced to $810 billion.