Climate scientist Noah Diffenbaugh, professor of earth system science at Stanford University, answered six big questions about global warming. Diffenbaugh explained how we know it’s real, how we know it’s human caused and how it affects weather.
Benjamin Spillman/RGJ

The landmark Paris Agreement, signed by nearly every nation on Earth except the U.S., aims to keep the world’s temperature from rising to dangerous, climate-shifting levels of 2 degrees Celsius above pre-industrial levels.

Now, a new study finds that even the best-case scenario of a 1-degree rise could increase the likelihood of extreme weather —including floods, droughts and heat waves — in the U.S. and around the world.

The frequency of extreme climate and weather events is already increasing, and many experts say man-made climate change is an important motivating factor.

“Damages from extreme weather and climate events have been increasing, and 2017 was the costliest year on record,” said study lead author Noah Diffenbaugh of Stanford University. “These rising costs are one of many signs that we are not prepared for today’s climate, let alone for another degree of global warming.”

More: Global warming makes ‘biblical’ rain like that from Hurricane Harvey much more likely

Keeping the world’s temperature to a 1-degree Celsius (1.8 degrees Farenheit) rise is informally known as an “aspirational” target of the Paris agreement, compared to the actual commitment of a 2-degree Celsius (3.6 degrees Fahrenheit) rise.

Another 2 to 3 degrees Celsuis of global warming would likely lead to three times as many record-breaking wet days across large chunks of the U.S., the study said.

While greater increases in the likelihood of extreme weather events would be reduced if the world achieves the aspirational…