美国一位权威气候科学家说，目前紧迫需要大幅度减少二氧化碳排放，来应对被严重低估的全球气候变暖问题。
美国宇航局戈达德空间科学研究院主任詹姆斯.汉森说，地球大气层中的二氧化碳已经达到“临界点”。汉森说，大气密度的安全标准20年前就已超过。
汉森和8名共同作者在为“科学”杂志撰写的一篇文章中摘要介绍了他们的研究成果。汉森和他的同事呼吁立即停建不截流废气排放的火力发电站，并在2030年前逐步淘汰现有火力发电站。
One of the leading climate scientists in the U.S. says a sharp reduction in carbon dioxide emissions is urgently needed to counter what he says is a vastly underestimated global warming problem.
The director of NASA’s Goddard Institute for Space Studies, James Hansen, says the world has already reached a “tipping point” for carbon dioxide in the atmosphere. Hansen says a safe atmospheric concentration level was passed 20 years ago.
He and eight co-authors summarized their findings in an article submitted to “Science” magazine. In the article, Hansen and his colleagues call for an immediate moratorium on building coal-fired power plants that do not capture their emissions, and for phasing out existing plants by 2030.