The numbers don’t lie: Humans are ruining this planet. Atmospheric carbon levels and ocean temperatures are going up. Arctic sea ice and biodiversity levels are going down—and no, the skyrocketing number of chickens doesn’t count toward biodiversity.
To comprehend and tackle those problems, scientists and policymakers need data—precise figures that show how Homo sapiens has transformed nearly the entire Earth in one way or another. To that end, a team of researchers has launched the Human Impacts Database, or HuID, a collection of over 300 (so far) critical figures, from sea level rise to the number of calories we as species get from animal products.
“Getting the numbers straight is the first step in trying to understand these systems, and we can learn a lot just by looking at the numbers,” says Rachel Banks, a biophysicist at Caltech and the Chan-Zuckerberg BioHub, and one of the lead authors of a paper describing HuID that publishes today in the journal Patterns. “And for sure, we want to keep these numbers updated and keep growing the database, but we also want to try to understand the Earth systems better.”
It’s worth your time to head over to the database and poke around. Banks and her colleagues combed through all kinds of information sources, from scientific papers to government reports, to find figures that run the gamut from measuring atmospheric processes to energy usage to mining. But if you spend enough time with HuID, you’ll find patterns. Earth’s systems are, after all, intimately linked with one another. “It seemed to us that a couple of key narratives emerged, and in a way they linked the story,” says study coauthor Rob Phillips, a physicist with Caltech and the Chan-Zuckerberg BioHub. “One of them is: What do we eat? And another one is: Where do we get our water? And then the last one is about power. If you follow those three threads, it’s a huge, huge part of the story.”
I got lost for hours in HuID. I’ve plucked out 14 particularly powerful, important, or just plain fascinating indicators—along with the graphs from the report that show their growth over time—that I think help illuminate those three threads.
Illustration: Human Impacts Database
First and Foremost: Global Warming
Thanks to humans loading the atmosphere with excess carbon, global surface temperatures have been rising steadily since 1850, as shown in the graph above. They’re now about 1.1 degrees Celsius warmer than in preindustrial times. That’s creeping up on the Paris Agreement’s optimistic goal of keeping that temperature below 1.5 degrees C, and an absolute threshold of 2 degrees. But it’s important to note that we’re talking global averages—so some places are warming much quicker than others. The Arctic, for example, is warming 4.5 times faster than the global average, because as it loses more sea ice, the darker underlying waters absorb more of the sun’s energy.
Illustration: Human Impacts Database
Rising Sea Levels, From Two Angles
As temperatures rise, glacial melt accelerates, driving up sea levels (shown in the graph above, in terms of millimeters above average sea level since 1900.)
Illustration: Human Impacts Database
