美國環保署22日發表風險分析報告《氣候變遷在美國:全球氣候行動的益處》指出,相較於毫無作為,全球採取氣候行動可以避免全美49個城市12,000人因極端氣候死亡,減少超過90%的死亡人口。
美環保署長Gina McCarthy說:「截至本世紀末,我們有機會每年拯救數萬人的生命和數千億美元的成本,越快採取行動,越能造福後代子孫。」
2011年夏天,受熱浪侵襲的紐約市。圖片來源:ChrisGoldNY。(CC BY-NC 2.0) |
報告指出,相較於無作為,採取全球氣候行動將在2050年達成每年讓12,000名美國人免於因空氣污染死亡,2100年更增加至57,000人。
報告總結,全球氣候行動可以避免氣候變遷在全美造成昂貴的損害支出。即刻採取氣候行動,效益將隨時間增加,延後減碳行動則將抵消這些效益。
氣候變遷的潛在後果包括更頻繁的野火、更長期的乾旱、熱帶颶風的數量、歷時和強度。美國太空總署科學家表示,地球均溫在20世紀內已經升高華氏1度,全球氣候變遷對環境已造成可見的影響。
這份報告將有助美國人準備12月巴黎氣候峰會上要簽訂的、具有法律約束力的全球氣候協議。巴黎峰會的氣候協議將取代1997年簽署的京都議定書。和京都議定書不同的是,巴黎氣候協議將限制開發中和已開發國家的溫室氣體排放。
《氣候變遷在美國:全球氣候行動的益處》是環保署氣候變遷衝擊與風險分析(CIRA)計畫的一部分。CIRA計畫跨20門美國公共議題,包括公共衛生、基礎建設、電力、水資源、農業、森林和生態系統。
報告比較兩種未來情境:一是溫度上升2度C以內,另一是不採取任何氣候行動,溫度上升9度F。接著量化兩種情境下的公衛、基礎建設和生態系統衝擊,計算出不作為的成本和減碳創造的效益。
報告檢視20個公共領域的結果顯示,全球氣候變遷行動確實能減少經濟衝擊。如果不採取任何氣候行動,到本世紀末,每年將要花費100億美元修復道路。若有效減碳,美國可以避免多達70億美元的類似損失。
報告預測,在無作為的情境下,海平面上升和暴風雨造成低窪地區48州的海岸財物損失將於2100年達到5兆美元。若採取調適措施,沿海地區的預估損失和調適成本減少至8100億美元。
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.
※ 全文及圖片詳見:ENS