KOJO NNAMDIYou're tuned in to The Kojo Nnamdi Show on WAMU 88.5, welcome. Later in the broadcast it's Kojo for Kids with National Aquarium CEO John Racanelli. Don't miss it. But first, in our warming world every disaster feels unprecedented. Hurricanes, wildfires, floods, heatwaves and disease outbreaks are getting more powerful and more frequent. So how are scientists connecting the dots between disaster and climate change? And what can we do to combat the climate crisis? Joining us now is Rebecca Hersher. Rebecca is a Journalist on NPR's Science Desk where she reports on natural disasters, outbreaks and health and environmental research. Rebecca Hersher, thank you so much for joining us.

REBECCA HERSHERHi, thanks for having me.

NNAMDIWell, Rebecca, right now we have a few disasters unfolding at once: Wildfires out west including the haze we saw here last week, hurricanes in the Atlantic, and the ongoing pandemic. It really does feel unprecedented. Is all of this due to climate change?

HERSHERWell, you know, it is all connected, and these types of really alarming weeks for a lot of people I think emotionally alarming where you have these concurrent disasters, right, like we had the wildfires. We've had these big powerful hurricanes that just keep pummeling the Gulf Coast and the East Coast. We have heatwaves and we have the pandemic. Those types of concurrent disasters when you talk to scientists, which I do all the time, they tell you, this is what climate change looks like.

HERSHERWhen we talk about like a climate signal, what are the hallmarks of a warmer earth, this is one of them, because even though, each individual event, say one wildfire or one storm or one extra hot week could have happened before, our hotter earth makes them all more likely. And so you get these weeks and these months even where everything is going wrong. It feels like everything is going wrong. And that's because, you know, let's say out West there's hotter air. There's more drought. Things dry out. Then when a fire starts it's much more likely to get really big, really intense, burn very powerfully and very far.

HERSHERAnd then in the oceans, the oceans are also getting hotter. So that means when a hurricane forms it's much more likely to get really big, really powerfully, drop a lot of rain. And so you end up with these situations where Americans are dealing with a lot of really bad seemingly unprecedented disasters all at once.

NNAMDIHow, for instance, is this hurricane season different?

HERSHERWell, this hurricane season has a lot of the hallmarks of climate change. You know, one of the things that's a climate signal that we expect when you look at climate models is as the surface of the ocean gets hotter, hurricanes have more fuel. And so, you know, right now we're seeing an unprecedented almost number of hurricanes, named storms. You know, we've gotten into the Greek letters. We've exhausted the alphabet and we've gone into the Greek alphabet. And part of that is because there's more fuel, more heat in the ocean to drive these storms.

HERSHERYou know, there's only -- I think it's the second most active hurricane season on record. And, you know, that's not random. It's because of our warming earth. And we also see these storms that are dropping more rain. So like Hurricane Sally, for example, this is the storm that just came ashore in Alabama and the panhandle of Florida. This type of storm that drops a lot of rain and moves really slowly, we actually know that that type of storm is driving by climate change.

HERSHERThere have been these attribution studies that look at those storms and say, well, what would have happened if that storm occurred with a less warm earth? And what would have happened is it would have dropped less rain. So that's the sort of thing that we're seeing in this year's hurricane season that really says, hey, this is climate change.

NNAMDIAnd what's the latest on the wildfires on the West Coast?

HERSHERWell, the wildfires on the West Coast are very large. They are burning very intensely. So one thing that I think is easy to forget is that not all wildfires are created equal. So just because it's burning doesn't mean that it's burning at the same temperature that it would have in the past. So these fires that burn in areas that are really dry, really hot, they burn very intensely and they can damage trees in a way that past fires might not have been likely to damage trees.

HERSHERYou know, fire is a normal part of the ecosystem in the West. But really intense fire that happens really frequently like fires burning in similar places over shorter periods of time over and over that can actually damage ecosystems rather than helping them be healthy. So that's one of the things that a lot of ecologists are worried about in a lot of the West is that these fires maybe are happening too frequently and too intensely to allow the ecosystem to bounce back in between.

NNAMDIRebecca, in the last few years in the Washington region we've seen so called thousand year floods one year after the other as well as record breaking heatwaves. We saw more 90 degree days in July than anytime in recorded history. Are the effects -- are these the effects of climate change right here at home?

HERSHERYes. Absolutely. You know, in some ways for me as someone who covers climate change, these really clear signals simplify. You know, for years we asked these questions. Is this climate change? And the answer was, well, maybe it's similar to what we would expect. But the answer now is just, yes. Yes, this is what climate change looks like. We've experiencing it right here in the Washington region. You know, sea levels have risen dramatically in this part of the country. It's one of the fastest growing sea levels.

HERSHERIf you look, even around the world, the mid-Atlantic is one of the places where sea levels are rising the quickest and that's for all sort of -- kind of the weeds reasons that have to do with icecaps and ocean currents. But the upshot is that when we get these extreme rain storms that we have gotten this summer and you pair that with higher baseline water levels, you know, in the rivers and tidal basin, you get significant flood events.

HERSHERAnd the same with heatwaves. When we get these would have been normal fluctuations in the temperature where it goes up a little bit, that's on top of a higher baseline. You know, we're running about already a few degrees warmer Fahrenheit than we were before industrialization. So when people are suffering through heatwaves, they're suffering through floods right here at home they're experiencing climate change. You know, you're living on the frontline of this crisis.

NNAMDIHere now is Anthony in Herndon, Virginia. Anthony, you're on the air. Go ahead, please.

ANTHONYYes. How are we doing? I've been thinking -- looking at this climate change. If you take satellite pictures of the earth and you look at how green it was back it in the 50s, how less green it is in the 60s, how less green it is in the 70s, we have been chopping down trees around the world recklessly. And not putting them back. And I'm talking about the big trees, the maples, the oaks, the elms, the birches, the willows, the really big trees. And we've just been chopping them down. And that is contributing to our climate change, but I have not heard anybody say anything about that. Is there any validity to this?

NNAMDIRebecca Hersher.

HERSHERI think that that is a really good point. And I think that scientists would totally agree with you. Deforestation is a big problem. It's actually part of the international diplomacy talks when we talk about how to address climate change globally, accounting for trees all over the world is a big part of that. Trying to slow the rate of deforestation and even reverse it by planting more trees, exactly what you said, that is a priority for a lot of countries.

HERSHEREspecially countries that actually don't emit very many greenhouse gases. Maybe they already have moved to more renewable sources of energy or maybe they're very small countries or with small populations. They are very focused often on either protecting the forest they have or replanting forest in order to try to do their part to slow global warming. And when we talk about trees, you know, not all tress are created equal.

HERSHERWe also have to talk about, you know, in the tropics we have -- for example, in Brazil these big rain forests that are under threat from agribusiness and Brazil has a president right now who is more favorable to agribusiness and less favorable to trying to protect those forests. That's a big problem if you're a scientist or you're a policy person, who's trying to slow global warming.

HERSHERAnd then I think we forget about this. The trees around the Arctic, this is like Arctic Russia and northern Canada and Alaska. We were just talking about wildfire. You know, those trees are endangered not just from logging, but from fire, because we're seeing much higher temperatures in the Arctic. And that puts those really old forests that are full of carbon. They're big carbon sinks in danger from fire.

NNAMDIRebecca Hersher, a study from last year said that last year's climate would feel more like Mississippi's by the end of century if carbon emissions are not drastically cut. What can you tell us about that?

HERSHERWell, yeah, it's going to be a lot hotter. And when we talk about feel like Mississippi's climate, you know, it's not just the heat. It's the wet. You know, we think about the Gulf Coast sometimes if you've ever lived there or been there it is rainy. They get big rainstorms, big, powerful thunderstorms and if you live in the mid-Atlantic and you've been paying attention for the last 5 or 10 years you've probably noticed that we're getting these big, powerful storms, not necessarily hurricanes.

HERSHERThese are just what would have been sort of normal thunderstorms before the earth got hotter. But not they're dumping just catastrophic amounts of rain. So when we talk about flooding inside the District of Columbia, but also catastrophic flash flooding in Howard County, in parts of Virginia, that is part of what we're talking about when we talk about the climate feeling more like the Gulf Coast. We're talking about this flooding, which is really devastating to a lot of people.

NNAMDIHere is Derek in Rockville, Maryland. Derek, you're on the air. Go ahead, please.

DEREKOh, hi. Yeah, thank you. I'm just curious a little bit on when you talk about science, how much does economic science come into play. For instance, you know, I've done tons of reading on this. I'm an economist by trade. And I've looked a lot the data. And it is actually somewhat debatable whether there are more hurricanes now than there were typically, because we only really have about 100 years or 110 years of good data. And then when people also talk about, oh, they're so much more damaging now, well, of course, they're more damaging when you have a developed coastline of today than when you had an undeveloped coastline 50 years ago.

DEREKI think that, you know, yes it is happening. I think people agree, but I'm just kind of curious whether the guest knows anything about Bjorn Morganson (sic) and his books like "Cool It" and "False Alarm." And that quite often, you know, the scientists, they are one type of scientists. They're your type, which focuses on is it happening? And quite often the is it happening? turns into we need to --

NNAMDIGot to take a break. Thank you for your call, Derek. We will have Rebecca Hersher respond when we come back. I'm Kojo Nnamdi.

NNAMDIWelcome back. We're talking with Rebecca Hersher. She's a journalist on NPR's Science Desk about climate change and the effect it's having on several of the phenomena that we now experience. Rebecca, our caller Derek is suggesting that the science that you and others are looking at is not taking into account the scale of economies that have expanded over the last, oh I guess, century or so. And not taking that into account. He seems to be suggesting that all that we are experiencing now is, well, normal.

HERSHERWell, I think just to be completely clear. The science does take into account both the expansion of people into risky areas and what we're seeing on the global level when it comes to weather and climate patterns. And I think he brings up a good point. You know, one thing he was mentioning is that people concentrate in a developed coastline. And so when sea levels rise or we get these more powerful storms we see more damage. You know, something like $500 billion in damage in just the last five years from climate driven weather.

HERSHERSo that's a big number. And when we dig into why, one reason is that people continue to live in some of the highest risk areas, along coastlines, in low lying areas and that is what contributes to these costs. So rather than suggesting that climate change is maybe less of a problem I think that most scientists would say -- that suggest that climate change is much more of a problem, because it's almost demanding of us, of our policymakers, of our local leaders that we change the way we build, the way we live, the way we move and if we continue on the path that we're on we'll continue to see these just devastating damages, because people are living in the exact places that are in the path of the types of things that we're seeing more and more with climate change.

NNAMDIDerek, thank you for you call. Rebecca, and beyond just weather, there's the connection between our changing climate and disease. What does the climate crisis mean for the likelihood of future pandemics?

HERSHERWell, the intergovernmental panel on climate change, that's the UN's climate body, it's made up of hundreds of scientists all around the world, they looked into this. And, you know, pandemics one way that they start, it's probably the way that this one started is that people and animals have been in contact and a virus jumps from animals to humans, right? That is more likely as -- you know, we were talking deforestation earlier in the segment. As we cut down trees, animals are on the move. As the earth changes, weather patterns change, animals are on the move looking for spaces where they can thrive or perhaps their old spaces were getting too hot.

HERSHERAnd people are on the move, right? You know, disasters mean that people are displaced. Also the population is growing. So you have more people interacting with livestock, interacting with wild animals in the interface between forests and where people live. And that just means more and more and more opportunities for a virus to jump from animal to human and then from that human to everyone.

HERSHERAnd so, you know, that is the connection. When we talk about the connection between climate change and pandemics we can say that in our current trajectory we would expect more pandemics, because we're doing all the things -- all the ingredients are there for viruses to jump over.

NNAMDIIs there anything we as individuals can do to make a difference?

HERSHERWell, we need to reduce greenhouse gas emissions dramatically. Probably by about half in the next decade, and that is a tall order, right? You're not going to do that by recycling. But first of all, there's an election coming up. So we can all decide that this is a priority for us. Now what that means to you as a voter is up to you. But in order to reduce greenhouse gas emissions dramatically national action probably has to happen. That's what climate modelers say. And corporate and state and local action has to happen.

HERSHERSo a lot of states, a lot of cities, a lot of corporations that you probably buy things from, they are making promises right now. There has been a huge wave of promises made all the way from national all the way down to little companies to change the way they do business and emit less.

HERSHERAnd so if you're thinking as an individual that this is alarming to you and you want to do something about it, those are the places I think that you can look and really pull your citizen lever and say, I care about this and I'm going to act in a new way, or I'm going to spend my money in a different way or I'm going to vote in a different way. And that's sort of the way that you can contribute.

NNAMDIHere now is Maurine in Bowie. Maurine, you're on the air. Go ahead, please.

MAURINEYes. Thank you. And thank you for covering this topic, great discussion. I am calling to add on to the gentleman, who called earlier about loss of trees. And this is especially important in Maryland, because we are losing our forests and that's despite the current regulations for developers.

MAURINEAnd as a matter of fact, years ago there was a bill that environmentalists were trying to push through that said no net loss of forests and it never made it through the committee. So we need to call our representatives and make sure that they understand we do not want to keep losing forests. Planting new trees is wonderful. But new trees do not replace the larger trees that have been cut down, not for many years. And a lot of them end up dying.

MAURINESo we have Maglev coming up. And we have widening of 270 and the Beltway and guess, what? We're going to be losing a lot of trees and natural areas. The Maglev options go through Beltsville agricultural research center.

NNAMDIOkay. Allow me to have Rebecca Hersher respond.

HERSHERWell, you know, I think you're getting at an interesting tension also, because when we talk about transportation and about tree cover and the carbon budget so to speak there can be tension around redeveloping the way we get around, you know, maybe building more transportation sources that are not individual personal cars. And making sure that we retain tree cover and also that we have healthy like hydrological systems, right, with all this rain that this region is getting if we cut down trees and we've actually seen this in the D.C. suburbs especially you get a lot of runoff and that can be really damaging downstream.

HERSHERAnd so I think there are a lot of people in the D.C. region whether it's floodplain managers, whether it's scientists, hydrologists, who are trying to study, well, how exactly can we do all the things we want to do? How can we move ourselves more efficiently? And maintain healthy forests? And prevent excess runoff that would cause flooding? And it's a tightrope, but there is a way through.

HERSHERAnd I think we're quite lucky in this region actually. There's a lot of expertise I found in my reporting. Really great universities, but also very experienced local leaders, who are thinking about these issues, and I would say those are the people who are really on the frontlines of solving the problems that we're seeing.

NNAMDIWe got an email from HP in Riverdale Park, Maryland. "Last week, my house was flooded and it was mentioned that we have a 100 year flood plan of, I guess, 3.1 inches a year. We had five inches fall a week and a half ago. What does this floodplain mean?" Floodplain, I'm sorry. Not flood plan, floodplain. "What does this floodplain mean? Will my house still be habitable in 5 to 10 years with climate change and the increase in volatile weather?"

HERSHERThat's a great question. So for that listener is in a position that a lot of Americans are in. So the 100 year floodplain I think is pretty poorly named. And a lot of scientists and people who study flooding agree with this that what 100 year floodplain really is is -- just tells you how likely it is that in any given year a flood will happen. And with climate change in a lot of places and this is true in the District and around the District that chance is going up. So if you had a 1 in 20 chance of flooding in a given year before this, maybe your chance is not 1 in 10, and it's hard to say. But I can point this listener and anyone else who is wondering about their flood risk to good new tool.

NNAMDIOnly got about a minute left, but go ahead, please.

HERSHERIt's called flood factor. And it will give you a 1 out of 10 rating, but also help you understand what your future flood risk might be as the earth gets hotter. It's not perfect, but it is one tool and there are more coming that can help people make these informed decisions.

NNAMDIIn the last 30 seconds, I know you hear this question a lot, but for those of us wondering what we can do to make a difference in all of this, what do you recommend?

HERSHEROh, I think helping yourself get educated about what it means for you is just the first step. You know, figure out, are you in a floodplain? Are you experiencing hotter summers? What can you do to keep yourself and your family healthy? Because if you're not healthy, then how can you help your community?

NNAMDIRebecca Hersher is a Journalist on NPR's Science Desk, where she reports on natural disasters, outbreaks and health an environmental research. Rebecca, thank you so much for joining us.

HERSHERThanks so much.

NNAMDIWhen we come back it's Kojo for Kids with National Aquarium CEO John Racanelli. Remember adults can listen, but only kids can call. I'm Kojo Nnamdi.