Stormy Forecast

How climate change affects trade.

Tim Boyle/Getty Images
Tim Boyle/Getty Images
Tim Boyle/Getty Images

For years, scientists have forecast that global warming will have a disproportionate impact on the world's poorest countries. Flooding will worsen in Bangladesh; the deserts in East Africa will expand; bigger, stronger cyclones will hit Indonesia. Now, two economists have divined yet another negative outcome of a hotter world for low-income countries: less trade.

Benjamin Jones of Northwestern and Benjamin Olken of MIT analyzed global import-export data as well as temperature and precipitation readings. They found that for poor countries, in a given year, every 1-degree Celsius increase in average nationwide temperature cut the growth rate of exports 2 to 5.7 percentage points. For rich countries, hotter or cooler temperatures had no measurable effect.

Poor countries are especially at risk because they depend so heavily on farming and light manufacturing -- think cornfields and T-shirt factories. Temperature rises wipe out crops and hurt performance among factory workers. And because such countries tend to have little domestic trade and derive most of their income from exports, small changes can add up fast. If global warming cuts the export growth rate only half a percentage point per year, after 20 years it adds up to 10 points, Jones explains -- a difference that could be even more disastrous for poor countries than the punishing weather that will accompany it.

For years, scientists have forecast that global warming will have a disproportionate impact on the world’s poorest countries. Flooding will worsen in Bangladesh; the deserts in East Africa will expand; bigger, stronger cyclones will hit Indonesia. Now, two economists have divined yet another negative outcome of a hotter world for low-income countries: less trade.

Benjamin Jones of Northwestern and Benjamin Olken of MIT analyzed global import-export data as well as temperature and precipitation readings. They found that for poor countries, in a given year, every 1-degree Celsius increase in average nationwide temperature cut the growth rate of exports 2 to 5.7 percentage points. For rich countries, hotter or cooler temperatures had no measurable effect.

Poor countries are especially at risk because they depend so heavily on farming and light manufacturing — think cornfields and T-shirt factories. Temperature rises wipe out crops and hurt performance among factory workers. And because such countries tend to have little domestic trade and derive most of their income from exports, small changes can add up fast. If global warming cuts the export growth rate only half a percentage point per year, after 20 years it adds up to 10 points, Jones explains — a difference that could be even more disastrous for poor countries than the punishing weather that will accompany it.

Kayvan Farzaneh is an editorial researcher at Foreign Policy.

More from Foreign Policy

An illustration shows George Kennan, the father of Cold War containment strategy.
An illustration shows George Kennan, the father of Cold War containment strategy.

Is Cold War Inevitable?

A new biography of George Kennan, the father of containment, raises questions about whether the old Cold War—and the emerging one with China—could have been avoided.

U.S. President Joe Biden speaks on the DISCLOSE Act.
U.S. President Joe Biden speaks on the DISCLOSE Act.

So You Want to Buy an Ambassadorship

The United States is the only Western government that routinely rewards mega-donors with top diplomatic posts.

Chinese President Xi jinping  toasts the guests during a banquet marking the 70th anniversary of the founding of the People's Republic of China on September 30, 2019 in Beijing, China.
Chinese President Xi jinping toasts the guests during a banquet marking the 70th anniversary of the founding of the People's Republic of China on September 30, 2019 in Beijing, China.

Can China Pull Off Its Charm Offensive?

Why Beijing’s foreign-policy reset will—or won’t—work out.

Turkish Defense Minister Hulusi Akar chairs a meeting in Ankara, Turkey on Nov. 21, 2022.
Turkish Defense Minister Hulusi Akar chairs a meeting in Ankara, Turkey on Nov. 21, 2022.

Turkey’s Problem Isn’t Sweden. It’s the United States.

Erdogan has focused on Stockholm’s stance toward Kurdish exile groups, but Ankara’s real demand is the end of U.S. support for Kurds in Syria.