View Earth After Climate Change


CLIA FEW YEARS ago in a lab in Panama, Klaus Winter tried to conjure the future. A plant physiologist at the Smithsonian Tropical Research Institute, he planted seedlings of 10 tropical tree species in small, geodesic greenhouses. Some he allowed to grow in the kind of environment they were used to out in the forest, around 79 degrees Fahrenheit. Others, he subjected to uncomfortably high temperatures. Still others, unbearably high temperatures—up to a daily average temperature of 95 F and a peak of 102 F. That’s about as hot as Earth has ever been.

It’s also the kind of environment tropical trees have a good chance of living in by the end of this century, thanks to climate change. Winter wanted to see how they would do.

The answer came as a surprise to those accustomed to dire warnings that climate change will turn the Amazon into a desert. The vast majority of Winter’s seedlings didn’t die. In fact, most thrived at significantly warmer temperatures than they experience today, growing faster and larger. Just two species succumbed to the heat, and only at the very highest temperatures. The trees’ success echoes paleontological data, which hints that warmer temperatures can be a boon for tropical forests. After all, the last time Earth experienced average temperatures of 95 F, there were rainforests in Michigan and palm trees in the Arctic.

That doesn’t mean climate change won’t affect tropical forests of today. It already is. And it definitely doesn’t mean humans needn’t worry about global warming. Climate change will be the end of the world as we know it. But it also will be the beginning of another.

Mass extinctions will open ecological niches, and environmental changes will create new ones. New creatures will evolve to fill them, guided by unforeseen selection pressures. What this new world will look like, exactly, is impossible to predict, and humans aren’t guaranteed to survive in it. (And that’s if civilization somehow manages to survive the climate disasters coming its way in the meantime, from superstorms to sea level rise to agriculture-destroying droughts). Still, experiments like Winter’s offer a glimpse.

A warmer forest

Adapting to a warmer world will be long and painful process for the rainforest, and many species won’t make it through. Even so, “there will still be tropical forests in 2100,” says Simon Lewis, a plant ecologist at University College London and the University of Leeds. They will probably even contain many of the same species ecologists know today, including some of the trees in Winter’s experiments.

Read more at WIRED