Your grandchildren may pay a bigger price for global warming than you thought.

A hotter Planet Earth will cool down national economies, according to fresh research from scientists at Stanford University and the University of California, Berkeley.

Average U.S. income could shrink 36% by 2100 because of climate change from what it would be without global warming, they say. That is more than other, earlier studies have suggested.

But not all countries will suffer. Russia, Canada and countries in Northern Europe should benefit from warmer temperatures, according to the scientists’ models, because they have yet to reach what the scientists called the optimal average temperature for an economy — 55 degrees Fahrenheit, roughly where the U.S. is now.

“We were surprised at how important temperature is for the global economy,” said Solomon Hsiang, an associate professor of public policy at Berkeley and one of the co-authors of the study along with Marshall Burke, an assistant professor in earth system science at Stanford, and Edward Miguel, Oxfam professor in environmental and resource economics at Berkeley.

Global per capita gross domestic product will be down 23% at the turn of the next century if global warming isn’t slowed, the study found. The impact will be more severe in China — average income will shrink 43%—and Mexico, where average income could plunge 73%.

While scientists (and Pope Francis) widely believe global warming is happening, U.S. politicians are more divided on the issue. Even those who say the climate is changing disagree on whether humans are the cause.

This study was published in the magazine Nature ahead of a summit that begins Nov. 30, where governments hope to agree on fresh measures to reduce carbon-dioxide emissions blamed for global warming.

In coming to their conclusions, the scientists compared the performance of national economies when temperatures were normal over the 50 years to 2010 to when the weather was warmer or colder than average. They then looked at estimates of future temperature changes and forecasts for economic growth without climate change. Their data-crunching also showed that output rose as the average temperature approached 55 degrees and fell faster and faster as it got hotter than that.

The view on 2100 reflects the cumulative impact of what could be small changes, just as a headwind doesn’t necessarily have an immediate impact on how long an airplane flight will take.

Don’t expect the U.S. and other rich countries to be saved by more air conditioning, Hsiang said. Many people still have to be outside for work — farmers, construction workers and delivery people, for example. But even those whose work isn’t outside avoid doing things in the heat, as Hsiang said he experienced on a recent trip to Arizona. That avoidance strategy could be keeping them from doing something that would be good for economic growth.

In addition, air conditioning, and the power systems needed to run it on peak days, is expensive. The money spent on that can’t be spent on other investments that could make us more productive in the future, such as education, Hsiang noted.

Even if the U.S. doesn’t get as hot as other countries, Hsiang said, its economy can be affected because of global demand for its goods and services.

Where is the average temperature now 55 degrees? The San Francisco Bay Area, Hsiang said, is pretty close.

So, it turns out, is New York City.