Climate Change and the Drought: An Interview With Katharine Hayhoe

Photo courtesy of Texas Tech University

Climate scientists Katharine Hayhoe says the drought was exacerbated by climate change.

We’ve been posting videos and reports recently from a series on the drought by PBS NewsHour done in collaboration with StateImpact Texas. The series is part of a larger project by PBS NewsHour in partnership with local public media, Coping With Climate Change, that looks at how a transforming climate affects everyday life. Today’s piece is an interview with Katharine Hayhoe, director of the Climate Science Center at Texas Tech University, about what role climate change played in the drought. 

Q: So Texas is still in the middle of this drought and it’s pretty extreme. Does this relate to climate change, and if so, how?

A: Whenever something happens, there is always the temptation to try to pigeonhole it either [as] an entirely natural event or [as a result of] climate change. But the reality is that every event that occurs right now is probably a little bit of both. Like in our case, with our drought, there is no question that it was initiated by La Nina.  But on the other hand, our temperatures this summer were really extreme.  We set all kinds of records, so there is a very strong possibility that climate change also played a role. In that sense, we have a little bit of both going on. We always have natural variability, but now we’ve gotten to the point where we’ve altered the background conditions of our atmosphere to such an extent that … climate change has a little bit to do with everything that happens around us. Here in West Texas we’re already really dry… so drought is almost the norm for us. But with climate change, what we see is through increasing temperatures and through increasing variability in our precipitation rainfall patterns, we have the potential for even more impacts on water in the future … It’s as if we have two dice and we always have a chance of rolling that double six, which would be that extreme event.  But with many of our events – including very high temperature days, extreme heat, and heavy rainfall – climate change has been kind of coming in and removing some of those other numbers off the dice and putting in more sixes … increasing our risk of having one of those [extreme] events.

Q: So you’ve said that climate change exasperates preexisting problems. What are some of the specific things that you see being affected now?

A: That’s a good question. So here in West Texas our main resource is water. We get most of [our] water from an aquifer underground but we are withdrawing water from that aquifer so quickly that it can’t replenish in time. So those aquifer levels are dropping sometimes more than 150 feet in some areas around West Texas. It’s estimated that large sections of the aquifer could effectively run out of water within 30 years. Now that has nothing to do with climate change. It’s just because we are withdrawing that water faster than it can replenish. So where does climate change come in? Well, by increasing the average temperatures, especially in the summer, means that we have more evaporation. So you need more water to provide crops with the same amount of irrigation if it’s hotter out.

Q: How do you differentiate between weather and climate? How do you explain to people who talk about events on “this particular day” or in “this particular place” or at “this particular time” whether that event is part of climate change or not?

A: Weather is what we experience from day to day. Weather is that incredible summer we remember like last summer, where we broke all kinds of heat records, or it’s that incredibly cold winter that was the coldest winter on record – that’s weather. Climate is the long term average of weather over at least 30 years. So when we talk about climate change, we’re not talking about one event or one summer or even an unusual year. We’re talking about long term changes that we’ve seen, data that goes back at least 30 years and often much longer than that.

Q: How would you explain how a drought and high temperatures relate to the overall climate of Texas? And how does the global climate change relate to conditions in Texas?

A: Here in Texas we are in a semi-arid environment which means that we are already pretty dry most of the time. What’s more is we have a long history of droughts in this region. If you look over the past couple of hundred years, we’ve had some very severe droughts that have occurred entirely naturally – so where does climate change come in? Here in West Texas we are very short on water. What climate change is doing is increasing our temperatures, and higher temperatures mean faster evaporation. So you need more water to provide the same amount of irrigation for crops if temperatures are higher.

Q: How do you explain the swings between wet years versus dry years?

A: Here in West Texas we are very sensitive to a pattern called El Nino and the flip side of that, La Nina. Whenever we have an El Nino, we tend to have very wet conditions here in West Texas. Whenever  we have La Nina ,we tend to have very dry conditions; it’s either feast or famine. We can have extremely wet conditions and record cotton crops one year, and then we can have record dry conditions and complete crop failure the very next year. If you look at our heavy rainfall events too, those are increasing in frequency here in Texas as well as around the US. So it’s almost like feast or famine. So that’s why it makes all the sense in the world to be smart to and to conserve our resources.

Q: What kinds of impacts on environment, people and the society are we seeing as a result of the drought?

A: The drought that we are experiencing right now, [the one] we are hopefully coming out of very soon, is going to have [a] fairly long-term impact. For example, we had enormous wildfires this year that burned down entire neighborhoods. It’s had a huge impact on our agricultural [and] natural resources [in] ecosystems like Big Bend National Park. But I hope that the biggest impact that the drought has had is to show us that we are vulnerable to variability and to changes in climate because we depend on water. We need water. We need it for our homes, we need it for our agriculture, we need it for our natural resources, our plants and our animals and our fish that live in it. So I hope what we’ve learned from the drought is that we all need to conserve our resources in a sensible, sustainable way to make sure that we all have enough to continue to increase our quality of life here in West Texas.

Q: Looking towards the future, what can you say is going to happen as far as the change in climate?

A: The big question is what’s going to happen in the future. And to answer that question, the first place we have to look is in the past. If we look at southwest Texas, going back several 100 years and even 1,000 years, we see that there have been huge droughts, droughts that are so big that people call them mega-droughts here in the southwest. So the one thing we can pretty much guarantee in the future is that we will continue to see droughts just because that’s a natural pattern for this region. But the other thing we know is that our planet is getting warmer. Year by year, decade by decade, gradually over long periods of time, we see that the earth’s temperature is rising and we know from very careful scientific studies that have been done, that the majority of this warming is due to human production of heat-trapping gases. We depend on coal and gas and oil for most of our energy. We can’t just stop using that today … so we know that some amount of climate change is going to continue because of the heat-trapping gasses that we’re producing, that our average temperatures will be rising here in Texas [and] around the world, that our extreme heat will become more frequent.

Read more at the PBS NewsHour website, Coping With Climate Change.