極端天災事件連連 直指北美氣候暖化 | 環境資訊中心

極端天災事件連連 直指北美氣候暖化

2008年07月08日
摘譯自2008年7月1日ENS美國,華府報導;游珮綺編譯;蔡麗伶審校

加州森林大火。圖片來源:Bryan Dahlberg「亞特蘭大市渴了、紐約市太熱了、第蒙市洪水氾濫」,這些情況在2008年之內通通都發生了。一份新出爐的聯邦政府報告預測,因為地球暖化,這種橫跨整個北美地區的極端氣候變化將越來越頻繁。

第一次在觀察和預測北美地區的天氣和極端氣候變化之後,進行了全面性的分析,根據該報告指出,因為人類活動不斷提升大氣中的溫室氣體濃度,使得乾旱、暴雨、過熱、劇烈的颶風等現象有可能變得越來越常見。

這是美國聯邦政府氣候變遷科學計畫(Climate Change Science Program, CCSP),及其氣候變遷研究小組委員會66月底所發表的一項科學評估。

該報告的聯合主筆卡爾(Tom Karl)博士表示,「報告中發現,全球暖化最常被問及的問題為:天氣和極端氣候將會發生什麼樣的變化?針對這個問題,上述的綜合分析和評估工具對整個北美地區進行測試,而所得出結論為,我們現在正目睹了這些改變,而且將會經歷更多的極端天氣和氣候的事件。」卡爾博士同時也領導美國國家氣候資料中心(National Climatic Data Center, NCDC)的相關研究,NCDC位於北卡羅來納州的艾西維爾。

這個報告是以科學證據為基礎,並發現世界暖化將伴隨著強度、時間、頻率和地理位置等各種程度變化的極端天氣和極端氣候。

「聯合國政府間氣候變遷小組」(UN's Intergovernmental Panel on Climate Change, IPCC)之前曾在全球範圍的基礎上,以同樣的程度內容來評估極端的天氣和氣候事件,但這是第一次針對北美地區所進行的科學性評估。

報告的另一聯合主筆梅爾(Gerry Meehl)博士也指出,「我們將持續目睹全球暖化所造成的極端天氣和氣候災害的一些重大衝擊;而本報告是第一次將重點聚焦於整個北美地區極端氣候的改變。」梅爾博士亦是美國國家大氣研究中心(National Center for Atmospheric Research, NCAR)主席,NCAR位於科羅拉多州的博爾德市。

根據氣候變遷科學計畫報告指出,過去50年來的全球暖化主要是由於人類活動所造成的溫室氣體增加。

而報告中也預測,在未來,伴隨著熱浪來襲,不管白天或晚上天氣將異常酷熱,清涼的夜晚很有可能會變得越來越少。

Extreme Weather Events Predicted for Warming North America
WASHINGTON, DC, July 1, 2008 (ENS)

Atlanta is thirsty, New York is sizzling, Des Moines is flooded - all these situations have happened this year, and a new federal government report predicts an increasing frequency of the same kinds of extremes across North America as the planet warms.

Droughts, heavy downpours, excessive heat, and intense hurricanes are likely to become more common as humans continue to increase concentrations of heat-trapping greenhouse gases in the atmosphere, according to first comprehensive analysis of observed and projected changes in weather and climate extremes in North America.

The federal government's U.S. Climate Change Science Program and its Subcommittee on Global Change Research released the scientific assessment late last month.

"This report addresses one of the most frequently asked questions about global warming - what will happen to weather and climate extremes? This synthesis and assessment product examines this question across North America and concludes that we are now witnessing and will increasingly experience more extreme weather and climate events," said report co-chair Tom Karl, PhD, who directs the National Climatic Data Center in Asheville, North Carolina.

The report is based on scientific evidence that a warming world will be accompanied by changes in the intensity, duration, frequency, and geographic extent of weather and climate extremes.

The UN's Intergovernmental Panel on Climate Change previously evaluated extreme weather and climate events on a global basis in this same context but this is the first specific assessment across North America.

"We will continue to see some of the biggest impacts of global warming coming from changes in weather and climate extremes," said report co-chair Gerry Meehl, PhD, of the National Center for Atmospheric Research in Boulder, Colorado. "This report focuses for the first time on changes of extremes specifically over North America."

Global warming of the past 50 years is due primarily to human-induced increases in heat-trapping gases, according to the Climate Change Science Program report.

For the future, the report forecasts more abnormally hot days and nights, along with heat waves, while cold nights are very likely to become less common.

全文及圖片詳見:ENS