20th Century Was Earth’s Hottest in 500 Years

The 20th century was the hottest in more than 500 years, Michigan researchers say. The Earth’s temperature has increased by about 1.8 degrees Fahrenheit since the 1500s, with about half of that in the 20th century, they report today in the journal Nature. In the Northern Hemisphere it rose even more--2 degrees Fahrenheit in the last 500 years, and 1.1 degrees in the 20th century alone.

Researchers from the University of Michigan and the University of Western Ontario reconstructed past trends in climate change by using data on subsurface temperature gathered from holes drilled into the ground at 616 sites on every continent except Antarctica.

--Compiled by Times medical writer Thomas H. Maugh II