For years now, atmospheric scientists have been handing us a set of predictions about the likely consequences of our emissions of industrial gases. These forecasts are critically important, because this group of experts sees grave risks to our civilization. And yet, when it comes to reacting to the warnings of climate science, we have done little.

If the science were brand new, that might make sense, but climate scientists have been making predictions since the end of the 19th century. This is the acid test of any scientific theory: Does it make predictions that ultimately come true?

In the early 20th century, Albert Einstein’s new and controversial theory of relativity predicted that gravity would cause light to bend. It sounded crazy, but a solar eclipse in 1919 provided the opportunity to test it as starlight passed near the blotted-out sun. Einstein’s theory was proved, turning him into a celebrity overnight.

When medicine delivered a wave of vaccines in the 20th century, doctors predicted that widespread use would cause childhood deaths from illnesses like whooping cough and diphtheria to fall. The public trusted the doctors, and those deaths plummeted.

So what predictions has climate science made, and have they come true?

The earliest, made by a Swede named Svante Arrhenius in 1897, was simply that the Earth would heat up in response to emissions. That has been proved: The global average temperature has risen more than 1 degree Celsius, or almost 2 degrees Fahrenheit, a substantial change for a whole planet.