Climate models can’t explain what’s happening to Earth

THE ATLANTIC

Fifty years into the project of modeling Earth’s future climate, we still don’t really know what’s coming. Some places are warming with more ferocity than expected. Extreme events are taking scientists by surprise. Right now, as the bald reality of climate change bears down on human life, scientists are seeing more clearly the limits of our ability to predict the exact future we face. The coming decades may be far worse, and far weirder, than the best models anticipated.

This is a problem. The world has warmed enough that city planners, public-health officials, insurance companies, farmers, and everyone else in the global economy want to know what’s coming next for their patch of the planet. And telling them would require geographic precision that even the most advanced climate models don’t yet have, as well as computing power that doesn’t yet exist. Our picture of what is happening and probably will happen on Earth is less hazy than it’s ever been. Still, the exquisitely local scale on which climate change is experienced and the global purview of our best tools to forecast its effects simply do not line up.

Today’s climate models very accurately describe the broad strokes of Earth’s future. But warming has also now progressed enough that scientists are noticing unsettling mismatches between some of their predictions and real outcomes. Kai Kornhuber, a climate scientist at Columbia University, and his colleagues recently found that, on every continent except Antarctica, certain regions showed up as mysterious hot spots, suffering repeated heat waves worse than what any model could predict or explain. Across places where a third of humanity lives, actual daily temperature records are outpacing model predictions, according to forthcoming research from Dartmouth’s Alexander Gottlieb and Justin Mankin. And a global jump in temperature that lasted from mid-2023 to this past June remains largely unexplained, a fact that troubles Gavin Schmidt, the director of NASA’s Goddard Institute for Space Studies, although it doesn’t entirely surprise him.

“From the 1970s on, people have understood that all models are wrong,” he told me. “But we’ve been working to make them more useful.” In that sense, the project of climate modeling is a scientific process that’s proceeding normally, even excellently. Only now the whole world needs very specific information to make crucial decisions, and they needed it, like, yesterday. That scientists don’t have those answers might look like a failure of modeling, but really, it’s a testament to how bad climate change has been permitted to get, and how quickly.

The Earth is an unfathomably complex place, a nesting doll of systems within systems. Feedback loops among temperature, land, air, and water are made even more complicated by the fact that every place on Earth is a little different. Natural variability and human-driven warming further alter the rules that govern each of those fundamental interactions.