Climate Sensitivity

EE: [00:00:00] We were very much interested in what climate change is going to due to the availability of water. Would the region experience have more water in the future or less water? When we started this research like, you know, 10 years ago we basically didn't know.

LHF: [00:00:17] Welcome to TILclimate, the show where you learn about climate change with real scientists. I’m your host Laur Hesse Fisher from the MIT Environmental Solutions Initiative.

You might have heard about how, with climate change, some parts of the world will get wetter, some drier. Some will experience more heat waves, more mosquitoes… but other regions might actually benefit economically. Why is this? We spoke with an MIT professor who is looking at how different parts of the world will be impacted differently with climate change, and sometimes in some pretty surprising ways.

EE: [00:00:53] My name is Elfatih Eltahir and I'm a professor in the Department of Civil and Environmental Engineering.

LHF: [00:00:59] Prof. Eltahir studies how things like deforestation, agriculture, and climate change effect larger systems, like the water cycle or heat waves.

EE: [00:01:10] But let me tell you what I really specialize on, you know, we all know about climate change. We know that it's real and it's significant and it's having an impact. A lot of studies have been done looking at processes at the global scale: how we want to limit warming to 2 degrees. On the other hand, a lot of the action around climate change happens at local and regional scales.

LHF: [00:01:33] So Prof. Eltahir and his team’s focus is on the local and regional level. Let’s start in Africa. And a big issue here -- is mosquitos.

EE: [00:01:43] … if you look at malaria, it's already a problem, it's a big problem in Africa.

EE: [00:01:47] we spent like 10 12 years studying the connections between malaria and the environment. So going into villages and instrumenting rain and temperature and extent of water pools and and also monitoring mosquitoes, their habitat, where do they breed, and how they interact with humans. And developing very sophisticated models that crystallizes our understanding of how the connection is between the environment and malaria.

LHF: [00:02:17] Their computer models both map the transmission of malaria today, and also link with global computer models.

EE: [00:02:24] We take the projections from those global climate models, and we force our models to be able to project what's going to happen in the future. We find that you know in West Africa for example, which is the hottest spot for malaria, that climate change is not likely to increase the burden of malaria. Other regions of Africa we looked at like the East African Highlands,there isn't much malaria because that area is relatively colder, and over there, warming may actually make things more favorable for malaria transmission.

LHF: [00:02:56] And why is that?

EE: [00:02:56] There is a there is an optimal temperature range for malaria to basically exist in a region. So West Africa is in the warmer side of that optimal range. And East Africa is in the colder side of that optimal range. And so if you think of warming, it will push West Africa outside of the optimal range while it may be drag East Africa into the optimal range.

LHF: [00:03:23] While that’s good for West Africa, countries in Eastern Africa will need to prepare for something they haven’t really ever faced before.

Now let’s head to northern Africa. A big issue there is water.

EE: If you look at water availability in the Nile, you know, there is already a conflict of water even without climate change. There is too many people and too little water to the extent that there are conflicts between countries like Ethiopia and Egypt about how to share that Water Resource. The good news is that in the Nile basin our models show us that you will get a little bit more water, may be in the order of 10 15 percent. Which is good news. I mean, it could have been you know less water.

LHF: [00:04:07] The only problem is, that this water isn’t going to come consistently -- there will be more flood years and more drought years.

EE: [00:04:17] And so what the engineering solution to problem like that is you have to build more storage capacity. So you store water from years of floods to the years of droughts. and so you secure and capture that additional water that's going to come to the region. So that's that's the story for the Nile.

LHF: [00:04:34] There are other parts of the world that may actually benefit from climate change.

EE: [00:04:40] That's will happen in Northern latitudes. In places like in Russia and maybe some places in Canada.

LHF: [00:04:47] How would they benefit?

EE: [00:04:48] From increased rainfall. From you know warmer temperatures. Different crops that are now more-- less optimal becoming more optimal. So there could be there could be benefits for at local and regional scales.

LHF: [00:05:01] Yeah, in fact, arctic melting from climate change is opening up some ship passageways that used to be covered by ice, making shipping faster and easier than it’s ever been for northern countries. And as ice melts in Greenland, the country has found valuable deposits of minerals that could allow them to enter a new, lucrative market.

If we skip over to Asia, though, it’s a totally different story.

EE: [00:05:29] If you look at heat waves in Asia, there are already people dying in some regions of Asia when we have severe heat wave that happen in summer. In the future, the region around the Persian Gulf and south Asia is going to experience some of the most intense heat waves that has ever been observed.

LHF: [00:05:50] This is because not only will the temperature be rising, but so will humidity.

EE: [00:05:56] And so you could think about it in simple terms as the degree of mugginess in the atmosphere.So here around Boston sometimes in July and August, you know, it's not only hot but it's also hot and humid. And so in that condition usually if it's really bad then people would be complaining.

LHF: [00:06:16] Weather apps and forecasts will sometimes tell you what the temperature is going to be, and then what it feels like outside. You know like the actual temperature might be 80 F, but it could feel like 95 F, because of the humidity. The thing is, is that when the “feels like” temperature reaches 95 F, for a long period of time, it can be really dangerous outside.

EE: [00:06:42] And the reason we say six hours is because that’s the exposure time that's needed to have really significant impacts. It Starts posing risks for the survival of humans they risk their health. They risk survival basically.

LHF: [00:06:57] I’ve heard of places in the Middle East hitting record highs of 114 F. That’s a lot higher than 95, but the two important pieces here are the humidity and the length of time that this heat lasts.

EE: [00:07:12] A region in Asia that extends between the Persian Gulf and Eastern China could be the hottest spot for for heat waves that people are going to experience under global warming.

We have projected severe heat waves in the future to happen in areas where you have hundreds of millions of people. The population impacted in Northern India, Bangladesh, and Pakistan, it’s not only there are many people there but also relatively poor people who do not have access to, you know, air conditioning now. Hopefully they do in the future. It's not like it's all the time going to be these temperatures. You are going to have once in a decade such extreme conditions, but if a human population is not protected by technology, like air-conditioning, you know events like that would be significant enough to wipe out wide populations. Hopefully society will take action and will be avoided.

LHF: [00:08:10] Prof. Eltahir’s team assesses the possible climate impacts under a range of different scenarios, like if society were to reduce emissions significantly, or by a little, or not at all. If we keep on going the way we’ve been going scientists call that “business as usual”.

EE: [00:08:33] Unfortunately, that's what's taking place, in the global sense, that we are going business as usual. And so under those severe business-as-usual scenarios, the most severe conditions we simulate could happen.

A lot of what motivates my research is to inform people at the local level about things that they care about so that they participate in the formulation of the policy based on science rather than based on you know misinformation.

I'm reminded that the New York Times had a map in which they asked people in the US do they think that climate change is going to impact people in general. People say yes it's going to have an impact around the country. And when you ask them if climate change going to have an impact on you and like your local community, and the answer people didn't think that is going to have a lot of impact on their local community.

And so I think informing citizens about about these impacts at local scale and focusing on phenomena that they really relate to and they care about could help.

LHF: [00:09:49] We know it can be hard to find information about how your part of the world will be impacted by climate change. If you go to tilclimate.mit.edu, that’s tilclimate.mit.edu, and visit this episode’s show notes, we’ve linked some resources that you can use to start to get a better sense of what the future might look like near you.

Thanks to Prof. Eltahir for joining us and to you for listening. I’m your host Laur Hesse Fisher from the MIT Environmental Solutions Initiative. We’ll see you next time.