When Trump announced that the U.S. would be exiting the Paris Climate Accord, he justified his actions by saying that the agreement would “undermine our economy” and put the country “at a permanent disadvantage.”
However, according to a research letter published in Nature this morning, this justification is quite plainly not true. If most countries limit global warming to 1.5 ºC or less through the end of the century, the global economy will avoid $36.4 trillion in economic damage.
The U.S., as a country, has the highest emissions behind only China, and has a 76 percent chance of economic growth, just if Paris targets are reached. But the U.S. isn’t the only country that stands to benefit: 71 percent of countries have a chance at economic gains. Some counties are more likely to experience gains than others, and tropical countries have a 99 percent chance of economic gain if Paris Accord targets are reached.
This is the largest study of its kind to analyze how long-term climate change impacts GDP, country-by-country, on a global scale. It involved more than half a century of economic data, and the input of over forty different climate warming scenarios. Before now, the long-term economic stakes behind the Paris Accord were much less clear.
The researchers also took “discounting” into account—which is basically the notion that a given amount of money will be worth less in the future than it is now. In a teleconference call with The Outline and several other publications, lead researcher Marshall Burke noted that their “discounting” calculation over the next century is approximate. But it’s clear which countries that stand to economically benefit from the Paris Accord. It’s simply a matter of how much they’ll benefit.
This research also highlights a central problem in climate change mitigation: politicians in office for a finite amount of time—people with the power to actually make policy changes—are motivated to pursue short-term economic growth they can see while their in office. The long-term benefits of international cooperation can be practically certain, as they are in this case, but if these benefits will be reaped when they’re out of office, the idea of cooperation is less attractive.
But if countries follow the actual steps they've have agreed to curb emissions, we should actually expect 2.5–3 °C of global warming—which is a catastrophic, worst case scenario. The research letter notes that if countries actually want to meet the Paris warming target of limiting warming to 1.5 °C, they’d have to limit emissions far beyond what the Paris Accord outlines. “Achieving the 1.5 °C target is likely to reduce aggregate damages and lessen global inequality,” the research letter reads. “And failing to meet the 2 °C target is likely to increase economic damages substantially,” and create a global rise in economic inequality.
We’ve known for years that the average temperature of a country influences its economy. Biologically, many profitable crops function best at cool temperatures. Humans also tend to work best under mild temperatures. But of course, tropical areas are also more likely to be subject to the long-term economic consequences of violent European colonization. Countries that will be most affected by the fallout of climate change are already unfairly disadvantaged thanks to systemic factors that have nothing to do with their regular weather.
It’s important to note that this research is largely an underestimate. In other words, it doesn’t account for “climate tipping points,” or points of no return where an environmental problem reinforces itself and becomes worse and worse. For example, the more the Greenland ice sheet melts, the less sunlight that ice sheet can reflect back into space. This traps more heat in the air, which exacerbates the melting rate.
It is possible that certain countries will develop technology that can mitigate the damage that heat can inflict on an economy… somewhat. Genetically engineering crops to become more heat resistant is a partial solution, but an incomplete one. Making air conditioners widely available will help human health, but it won’t do much to mitigate the effects of working outdoors in sweltering heat. If countries don’t reduce emissions globally, even the best carbon recapture machines don’t stand a chance against large-scale environmental feedback loops.
Extreme weather events—which are more likely to occur due to climate change—were considered in the calculation since they can cost a country billions of dollars in economic damage—a significant blow to a country’s GDP.