The earth is warmer than it’s been in at least 400 years, according to a study released today by the National Research Council. Many places, the report says, experienced more “exceptional warmth” in the last 25 years than since the year 900.
The earth’s temperature has increased 1 degree Fahrenheit in 20th century, the report concludes.
The report was sanctioned by the U.S. Congress, after climatologist Michael Mann and two colleagues concluded that the Northern Hemisphere’s warming late in the 20th century was without precedent for the previous 1,000 years. Their graph showing a pronounced rise in temperatures – known as the “hockey stick” – showed the 1990s as the warmest decade in that time.
Mann’s conclusion is plausible, the scientists’ newly released report says, though it had less confidence that the trend was unprecedented before 1600 – about the time the Tudors were giving way to the Stuarts in England.
The full report is available online. Check out this graphic to get an idea of how current temperatures compare with the last 1,100 years of data.
Or click here for the table of contents.