Past climate change ‘tipping points’ can help us prepare for future

Of all the creatures on Earth, humans manipulate their environments the most. But, how far can we push it before something drastic happens? Scientists are calling for a better understanding of past extreme climate change events in an attempt to anticipate future changes.

Enter geoarchaeologist and anthropologist C. Michael Barton at Arizona State University. The School of Human Evolution and Social Change researcher, along with Foundation Professor Sander van der Leeuw and an international and interdisciplinary team, published their analysis this week in the journal Nature Geoscience.

“We’ve been putting a lot of chemicals into the atmosphere and changing the heat of the atmosphere for a long time, and really intensively for 150 years,” Barton said. “And, things are still chugging along. Temperatures are slowly going up globally, but we haven’t seen a huge, dramatic shift. However, complex systems are potentially vulnerable if you push too much.”

Barton studies Earth’s many systems – specifically the water cycle and landscapes – and how humans alter these systems.

“People tend to look at how far you can push things before suddenly everything changes,” Barton said. “And that’s what’s considered the tipping point.”

For a complex systems specialist like Barton, almost everything can be viewed as systems or cycles. A tree grows and dies, and the decay returns nutrients to the soil. Water cycles through the Earth in different forms like rain, runoff, and evaporation.

Some of Earth’s major systems include the hydrosphere (water), the atmosphere (air), and the cryosphere (ice). All these systems are connected. This research on tipping points looks at the history of these systems to quantify small changes that can lead up to an abrupt, massive change, while also measuring how one abrupt change can trigger abrupt changes in other systems.