At the New Orleans Book Festival at Tulane University, award-winning science journalist and author Peter Brannen delivered a sweeping tour through Earth’s past, arguing that geological records offer the clearest warning yet about the consequences of unchecked carbon emissions.
Brannen, a contributing writer at The Atlantic and author of “The Ends of the World” and “The Story of CO2 is the Story of Everything,” said today’s climate crisis is not a theoretical future scenario, but a rerun of ancient carbon dioxide-related events that ended in catastrophe.
“I was familiar with climate change as this thing that we were worried about for the future,” Brannen said. “Then I had my mind blown by these geologists … I was kind of unaware that the planet had run experiments very similar to the one we’re running on it now, with CO2, several times in the past.”
Those experiments, he said, are literally written in the stone.
“[There is] this grim record in the rocks that shows you what happens if you just keep emitting CO2 and [making] it warmer and warmer … It’s literally the worst thing that’s ever happened in the history of life,” Brannen said, adding that over 90% of species on Earth have already gone extinct.
In his first book, “The Ends of the World,” Brannen chronicles how runaway carbon cycles triggered most of the planet’s major extinction events. His most recent book expands that argument, tracing how carbon dioxide has shaped the climate and Earth’s habitability across billions of years.
“It’s really helpful that geologists left these cautionary tales of [Earth’s] past for us to learn from and realize that this is kind of something you don’t want to mess with,” Brannen said.
Brannen said that certain ecosystems, such as the Amazon rainforest, coral reefs and major ice sheets, may cross irreversible thresholds if climate change continues. Coral reefs face a dual threat from global warming and ocean acidification due to carbon dioxide. Ice sheets, he said, contain positive feedback loops: “Once it starts melting, there’s nothing you can do.”
According to Brannen, these outcomes are not inevitable. He said we have a few more decades to avoid those scenarios, but there may be a fossil record of the damage for hundreds of millions of years.
Climate fatalism, the belief that climate change is an inevitable and irreversible process, is not scientifically accurate, said Brannen.
“If you stay rigidly factual, the ‘we’re-all-doomed’ scenario … is not actually an accurate characterization,” Brannen said. “I know that the world is not doomed, but I am really concerned about a lot of things, and I think that’s sort of the right space to inhabit.”