The National Academy of Sciences, reviewing a broad swath of scientific studies, concludes that the presently high temperature of the Earth is due to human action, not cyclical natural temperature spikes.
AP:
The Earth is the hottest it has been in at least 400 years, probably even longer. The National Academy of Sciences, reaching that conclusion in a broad review of scientific work requested by Congress, reported Thursday that the “recent warmth is unprecedented for at least the last 400 years and potentially the last several millennia.”
A panel of top climate scientists told lawmakers that the Earth is heating up and that “human activities are responsible for much of the recent warming.” Their 155-page report said average global surface temperatures in the Northern Hemisphere rose about 1 degree during the 20th century.
This is shown in boreholes, retreating glaciers and other evidence found in nature, said Gerald North, a geosciences professor at Texas A&M University who chaired the academy’s panel.
