Across much of the U.S., we’re still sweating it out after a massive heat wave enveloped broad masses of the country last week. It was one of the worst in decades, following on the hottest June on record, and what’s looking like will be the hottest year on record.
The U.S. has plenty of company in feeling the heat. Earlier this month, China was so hot they started doling out heat subsidies to outdoor workers. And, as I pointed out in my post back in May, millions across South Asia have been affected by record-shattering temperatures this year. That heat can have deadly affects. More than 130 people died directly from the heat wave and drought in India this spring—that’s not including indirect deaths that mostly occur in the very young and relatively old due to the additional physical stress of heat—and the year is far from over.
Heat in the summer does happen. But, it’s clear that we’re already beginning to see evidence of a trend for the worst. Because of climate change, episodes of extreme heat are only going to get longer, more intense and more frequent—in the U.S. and throughout the world. With time, having the means to adapt—and learning to do so—will become a matter of life or death.
So, how hot will it be?
My colleagues and I dove into the data as part of a comprehensive, multi-year study. Looking at the scenario where we fail to invest in mitigation and stick to our old business-as-usual ways, we see that by mid-century the average American will likely experience two to three times more hot days. And, by late-century, Americans could experience as much as three months over 95°F each year. The 1-in-20-year extreme heat events—like the one that happened in Chicago way back in 1995—will happen about every other year.
This extreme heat will strike us where we live—providing perhaps the most compelling and personal argument to do something about climate change. Take a look at the figure below. Find your state today and compare that to its summer temperature at the end of the century.
Many of the changes will be severe, to say the least. The hottest states will be hotter than anything the U.S. is used to. And, in fact, the heat most states will experience will be comparable to other, much hotter, countries around the world. To compare the future summer temperature of U.S. states to other countries in summer months, I worked with my colleague Dr. Jiacan Yuan at Rutgers University (We use June, July and August to calculate summer temperatures). The projections are startling.
If we stick to a business-as-usual trajectory, in some of our lifetimes, and certainly that of our children, people in Chicago—and all of Illinois—will experience summers as hot as India today. Washington, DC will be even hotter than India. The hottest states like Texas, Mississippi and Florida will see hotter summers than Sudan today. Maine, the coldest state in the continental U.S., will continue being the coldest but will be hotter than Mexico’s summers. If Maine is going to be hotter than Mexico and Chicago as hot as India then it is hard to imagine the strains intense temperatures will have on places like North Africa, the Middle East and other extremely hot regions of the world today.
The reality is, this extreme heat can have drastic impacts on human health.
This may be surprising, but heat is already the greatest weather-related killer in the U.S. today—more than tornados, floods and hurricanes. Of course, there are also a lot of deaths caused by cold temperatures today. With climate change, the increase in heat-related deaths will cancel out the cold-weather deaths until—in about 30 years from now—there will only be heat-related deaths. If we don’t mitigate or adapt, the extreme heat could cause as many as 21 deaths out of every 100,000 by the end of the century. That’s twice as high as the total number of deaths on America’s roadways in 2014.
The death toll will be large. But the U.S. is actually lucky—the heat’s worst effects can be tempered by air conditioning. Looking at the influence of air conditioning in the U.S. over time, the influence is clear. Heat-related deaths in the U.S. decreased by more than 80%, as the number of households with air conditioning rose by 73% from 1960 to 2004. Air conditioning will certainly continue to be an essential adaptation tool in the U.S. as it gets warmer, though the energy costs may be enormous. (Check out our infographic on the impact of A/C)
But not everyone is so fortunate, like many of those who suffered from the heat in India in May. While 85% of households in the U.S. have air conditioning, only 2% have it in India right now—and, like I pointed out in a previous post, nearly a third don’t have the electricity to power them up. Without the ability to adapt, people in emerging economies—who also happen to live in warm climates—experience a higher risk of death from extreme heat. That risk will only get worse over time. Last year, 2,400 people in India died directly from heatstroke (that’s not including all those who died from indirect heat-related causes). In the U.S., the number of direct heatstroke deaths was just 45.
These numbers point out a cruel reality of climate change. As the world warms, everyone will feel the heat—and its consequences. But, with less ability to adapt, it is the poor who won’t escape it.