But sometimes it can be hard to grasp what all the numbers and stats mean. For instance, when scientists say the Earth’s average surface temperature has gone up about 1 degree Celsius over the past 150 years or so, what does that really mean? Besides, hasn’t the Earth’s temperature always fluctuated?
Now a cartoon from Randall Munroe, a former roboticist at NASA, helps put the numbers into perspective.
Before scrolling through it, check out those axes.
Along the x-axis is temperature change. And each vertical block of color is 1 degree Celsius or 1.8 degrees Fahrenheit.
On the y-axis, we’ve got time. The whole cartoon, which starts at the end of the last ice age, represents about 22,000 years. People have been around for about 200,000 years. The dinosaurs were around about 65 million years ago. And Earth is 4.5 billion years old. So the graph is only a teeny-tiny period of the Earth’s lifetime.
“The cartoon is fantastic!” says Curt Stager, a paleoecologist at Paul Smith’s College.
“Really seeing the temperature changes over the long time scale helps you grasp, on a gut level, what we’re doing to the Earth,” he adds.
But there’s one problem with the graphic that makes it a bit misleading.
As you scroll up and down the graphic, it looks like the temperature of the Earth’s surface has stayed remarkably stable for 10,000 years. It sort of hovers around the same temperature for some 10,000 years … until bam! The industrial revolution begins. We start producing large amounts of carbon dioxide. And things heat up way more quickly.
Now look a bit closer at the bottom of the graphic. See how all of a sudden, around 150 years ago, Munroe changes the dotted line depicting average Earth temperature to a solid line. He makes this change because the data used …