| Tweet |
Global warming nears a million-year high
The Earth's rapid warming has pushed temperatures to their hottest level in nearly 12,000 years – and a hair’s breadth away from a million-year peak – according to a NASA study.
Global warming, which has increased temperatures by 0.2°C per decade over the past 30 years, has caused temperatures to reach and now pass through the warmest levels in the current interglacial period, which lasted almost 12,000 years.
The study, led by James Hansen and colleagues at NASA's Goddard Institute for Space Studies, reports that Earth is now within about 1°C of the maximum estimated temperature of the past million years.
"That means that further global warming of 1.0°C defines a critical level. If warming is kept less than that, effects of global warming may be relatively manageable,” he says.
Different planet
“During the warmest interglacial periods the Earth was reasonably similar to today. But if further global warming reaches 2°C or 3°C, we will likely see changes that make Earth a different planet than the one we know."
Hansen points out that the last time temperatures on Earth were that warm was in the middle Pliocene, about three million years ago, when sea levels were estimated to have been about 25 metres higher than today.
The repercussions of current warming are already being felt, researchers point out. “Vegetation cover is already expanding towards the pole in the Northern Hemisphere," causing yet further warming, Hansen says. He adds that such global warming could result in the release of further large amounts of greenhouse gas emissions. "Some of the largest warmings in the Earth’s history, and mass extinctions, may be associated with such release.”
The researchers say that curbing carbon dioxide emissions will be vital in reducing the escalation in warming, but other methods should also be attempted. They suggest, for example, that ships could be deployed in ocean regions to seed clouds, which would help reflect the Sun's heat and provide some much needed shade.
http://www.newscientist.com/article/dn10159-global-warming-nears-a-millionye
▲このページのＴＯＰへ HOME > 環境・エネルギー・天文板1掲示板
投稿コメント全ログ コメント即時配信 スレ建て依頼 削除コメント確認方法
題名には必ず「阿修羅さんへ」と記述してください。
掲示板,ＭＬを含むこのサイトすべての
一切の引用、転載、リンクを許可いたします。確認メールは不要です。
引用元リンクを表示してください。