Tiny critters could be a powerful tool against climate change

Ant - Samantha Henneke

By Maura Forrest

August 21, 2014

It’s possible that the key to slowing climate change is right in our backyards. Crawling around in our backyards, that is. A recent study published in the journal Geology shows that ants have a surprising ability—they can help to pull carbon dioxide out of the atmosphere.

In a process called “weathering,” ants can speed up the absorption of CO2 into rock by up to 335 times, the study finds, making them “one of the most powerful biotic weathering agents yet recognized.”

The drawing down of CO2 from the atmosphere into rock is a natural process that helps to keep the Earth habitable by preventing too much greenhouse gas from accumulating and heating up the planet.

Rock containing calcium or magnesium naturally absorbs CO2, which turns it into limestone over time.

But over a 25-year experiment that involved collecting basalt from a Hawaiian volcano, grinding it up and inserting it into ant nests, root mats, and the bare ground, researcher Ronald Dorn concluded that rocks in ant colonies absorb far more CO2 than they do elsewhere.

“It was pretty clear when I started processing samples of the minerals from the different areas that the ants were incredibly anomalous,” he said in an interview with Scientific American.

Dorn thinks the ants’ impact may be so substantial that they could have contributed to Cenozoic cooling—a period of climate cooling that started 49 million years ago, when ant species were proliferating, and eventually led to the ice age.

So what happens in ant colonies that produce such dramatic results? Unfortunately, nobody knows—including Dorn. He speculates that it could have to do with gland secretions from the ants, microbes, or some other chemical process that occurs in ant nests.

If scientists can unlock the secret of the ants, however, the implications could be huge.

The latest Intergovernmental Panel on Climate Change report warns that if we are serious about keeping global warming below two degrees Celsius—the agreed-upon limit to prevent dangerous climate change—we must not burn more than one trillion tonnes of carbon. Current estimates suggest we are already over halfway there.

If a substance secreted by ants could be isolated and “efficiently and economically used,” according to Dorn, it could help prevent some of the worst impacts of climate change.

“I don’t understand how the ants are doing the processes,” Dorn told Scientific American.

“I would love to get funding to figure this out . . . . That would be a dream.”

Photo Credit: Samantha Henneke