Millions are facing dangerous and potentially record-breaking temperatures as a heat wave grips much of the central and eastern United States.
Host Indira Lakshmanan speaks with Katharine Hayhoe, chief scientist at the Nature Conservancy, about why heat waves are starting earlier and lasting longer.
5 questions with Katharine Hayhoe
How does this week’s heat wave and similar ones in recent years compare with those ten and 20 years ago?
“We have always had heat waves in the summer. That’s a normal part of our weather. But as climate changes, as the planet warms decade by decade by decade, our heat waves are getting longer and stronger, more intense and more dangerous. So, the heat waves that we were used to when we were kids, that’s not what we’re experiencing now in the places where we live and that’s putting us all at risk.”
Well, you talk about the heat when we were kids. The U.S. today experiences twice as many annual heat waves on average as we did back in the 1980s when I was a kid. Why is it so much worse now?
“Well, what we’re seeing is natural weather patterns of hot and cold, wet and dry, superimposed over a long-term warming trend.
“And the reason the planet is warming is 100% up to us. By digging up and burning coal and gas and oil and by cutting down and burning trees, we are producing heat trapping gases that are building up in the atmosphere, wrapping an extra blanket around the planet.
“And just like you would if someone snuck into your room when you already had a low-grade fever — that would be our heat wave — and they put a pile of extra blankets on you when you are already experiencing a fever, you’d be that much worse. And that’s exactly what we are doing. Just look at last week in Europe and then look at what’s coming for us this week.”
What is the difference between the actual temperature and the heat index?
“So, we look at the thermometer and that tells us the temperature outside. But our body feels temperature, depending on how humid it is and even how windy it is, because that determines how our body can cool off.
“So, when you look at what the temperature is going to be like, you need to look at the humidex and you need to remember that heat affects us all, but it doesn’t affect us equally. Children, senior citizens, women who are pregnant, people who have chronic illnesses, they’re much more at risk from heat.”
Given what you just explained to us about the heat index, just how high could the temperatures feel in the coming days in two thirds of the country?
“Well, for example, New York, which you would not exactly think of as heat central, the National Weather Service is warning that heat index values could reach as high as 115 degrees Fahrenheit.
“You know, if you live in, you know, the Death Valley area, that might be something that you are not only accustomed to, but you know how to deal with.
“But when we have people who don’t understand how risky it is, how dangerous it is to spend time outside during those extreme heat events, that’s when we see the enormous, devastating impacts. Do not take heat lightly. It is very, very serious and it can kill.”
Are these heat waves just going to keep increasing in frequency and duration year after year?
“The changes that we’re seeing in heat waves are directly correlated to our emissions of heat trapping gases. But here’s the good news: We are already seeing a course correction.
“In the U.S. this year, solar has produced more electricity than coal for the first time ever in the U.S.
“Now, you might say, what about China? China installs more solar in a single year than the U.S. has in its entire history. So, the world is changing. The question is just how fast is it going to change?
“I live in Texas where we already get almost 40% of our energy from the wind and the sun that won’t run out on us and don’t produce heat-trapping pollution. But the faster we make this change, the safer we will be because climate change is not just some environmental issue that doesn’t affect our lives. It is literally a health issue. It’s an economic issue. It’s a human issue.
“If you’re a human being living on this planet, you have every reason to be concerned about the impacts and to advocate for and support the solutions that will give us a safer and healthier and better world.”
This interview was edited for clarity.
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Wilder Fleming produced and edited this interview for broadcast with Michael Scotto. Scotto adapted it for web.
This article was originally published on WBUR.org.
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