Was Earth already heating up, or did global warming reverse a long-term cooling trend?
- Written by Ellie Broadman, Postdoctoral Research Associate in Climate Science, University of Arizona

Over the past century, the Earth’s average temperature has swiftly increased by about 1 degree Celsius (1.8 degrees Fahrenheit). The evidence is hard to dispute. It comes from thermometers and other sensors around the world.
But what about the...