Mosquitoes, sun dimming, and the lives at stake

In this podcast, Eco-Business speaks to Prof Athar Hussain, head of the Centre for Climate Research and Development at COMSATS University in Islamabad, Pakistan. He is leading a study on how solar geoengineering would affect the spread of malaria in South Asia. The mosquito-borne disease has been receding from the region in recent years, but still affects millions and kills over 10,000 people annually across Asia.

Tune in as we discuss:

Professor Athar Hussain, head of the Centre for Climate Research and Development at COMSATS university Islamabad in Pakistan. Image: Athar Hussain.

• Details of Prof Hussain’s research.
• How the results could help South Asian policymakers better understand the effects of solar geoengineering.
• Whether sun-dimming is a technology we should take seriously today.

Edited transcript:

Q: Why did you decide to focus on the link between malaria and solar geoengineering?

In the past 10 years I have been working on climate change and its impacts, such as on agriculture and health, in Pakistan and South Asia.

Carbon dioxide is very stubborn. It stays in the atmosphere for approximately 100 years. So what we have produced today is going to stay in the air. Lots of progress has been made in the past 27 COP climate conferences, but it is not enough. So clearly we need to think of alternatives to reduce the impacts of climate change.

Solar radiation management is one way, typically by injecting sulfur particles way up in the atmosphere, around 25 kilometres above the Earth’s surface. It reflects a small fraction of incoming radiation, around 1 per cent, but it is enough to lower the temperature. As of now it is more or less only at the research and hypothetical stage. 

Malaria is a tropical and subtropical disease, and there many deaths and illnesses due to it in South Asia and Africa. So there is a legitimate and clear reason to study how climate interventions, like solar geoengineering, affects malaria. 

Q: What are some factors you are looking at in your research on malaria? Is it things like temperature and rainfall?

Water temperature, and the presence of water itself is a very relevant factor in the growth of larva. The water can come from rain, and in higher altitudes, ice or snow.

I have looked at both the consequences of temperature increase and changing rainfall patterns on malaria, and the current understanding is that with climate change, malaria distribution shifts towards the north in Pakistan.

Q: What is your initial hypothesis on how solar radiation management could affect the distribution of malaria in South Asia? Would it be a uniform shift or will it be pockets of different trends?

We are working to provide the detailed risk maps for South Asia, in Pakistan, India, Nepal, Bhutan and Bangladesh. All these countries have mountain ranges in the north, and with climate change we are expecting malaria to shift to these northern regions. With solar geoengineering, the northward shift will be slower. So this is one impact of solar radiation management on malaria in these South Asian countries.

Q: There is research showing that some strains of malaria spread best at cooler temperatures of around 25 degrees Celsius. One global study published in the Nature journal said that solar geoengineering will actually increase the rate of malaria transmission in some regions. Is this a significant trend you are expecting in South Asia too?

This is a very important question that needs to be addressed thoroughly. For example, there are malaria hotspots in the south of India. With solar radiation management, the hotspots will stay there because temperatures will not rise so much. There is a range of temperature over which mosquito larva feel more comfortable, typically between 16 to 29 degrees Celsius.

So more detailed studies at the level of the Union Council, the small administrative divisions in Pakistan, needs to be done. Estimates will be needed at this level because some regions will have cooler temperatures, some will have higher temperatures.

There are similar studies recently, but they are very general, looking at things globally. Detailed studies on each individual region and climate zone within Asia are needed.

In Pakistan, we have arid regions with little rain and high temperatures. We also have cold climates in the north. This is the same for countries like India and Nepal as well. Malaria may spread to these colder regions with climate change and temperature rise.

A clear plan for defending against malaria is needed, because that is how we can reduce economic burden on local governments.

Q: Are risks around how we use solar geoengineering part of your studies? One big fear of the technology is that if we start on it and suddenly stop, global warming is going to rebound, fast. Would you be looking at how that would affect the spread of malaria in South Asia?

This is a question being discussed in the modelling community. One solution is to terminate solar geoengineering slowly, so the sudden temperature rise does not happen. We also have to look at factors like upper atmosphere circulation and the distribution of the aerosol particles. This is a question that needs considerable dialogue and understanding.

We need the kind of understanding and communication as we have in our efforts to reduce carbon dioxide levels, in dealing with a transboundary, global issue like solar radiation management.

Q: How much help is the Degrees Initiative grant in enabling your research?

There are two aspects. First, the money helps with supporting several students and young, early-career researchers.

The second is that it supports an expansion of what I have trying to do in the past, to build a nucleus of trained professionals in climate change who can inform about its impacts on various societal sectors. 

Q: When can we expect to see the results for the malaria study?

I expect to be able to have discussions on this topic in the second-half of this year, by publishing the results and presenting them at national conferences. I expect to have initial results then.

Q: How much do people in South Asia know about solar geoengineering?

In Asia, people in more developed countries like Japan, South Korea, Singapore and partly China, are aware of climate change. In the rest of the countries, people are less aware of it, in both the general community and within policymakers.

We did a study in three countries in the global South, including from Pakistan, and we found that generally speaking, within those who are aware of the impacts of climate change, no more than 30 to 40 per cent are aware of solar geoengineering.

Granted this was a very small group, and we need to expand such surveys. At the same time we need to know the perception of educators and policymakers about solar radiation management. We also need to create more awareness on the technology, for example, on why it matters, what are its risks, and then, what should be our position on the discussion table.

Q: For the 30 to 40 per cent of people who know about solar radiation management, do they support it or are they against it? 

They support experiments in solar geoengineering, and they are of the opinion that this is not an individual problem and has to be solved collectively. 

They feel countries that are more technologically advanced in solar geoengineering should be leading, but it should also be clear what the role, contribution and impacts on the Global South are.

Q: In IPCC reports last year, it was mentioned that people in developing countries are more receptive to the technology than those in deveoped countries. What do you think about this, and is it a cause for concern?

There can be several reasons why. For example, the impact of heatwaves and floods are much higherin South Asian countries compared to other regions like in the United States, New Zealand, Australia andthe UK. So the concern is legitimate. People in the Global South are more concerned that these problems should be resolved quickly.

Q: Is South Asia ready for the deployment of solar geoengineering, if the world so decides to? If not, what are the key areas still missing?

As of now, very little information is available in terms of the impacts of solar geoengineering. This is exactly the gap that I’ve stated earlier. And I am only focusing on one specific area, on health and disease. 

The point is that much more work needs to be done to understand the consequences of solar radiation management before decisionmakers can state their preferences on the technology.

If solar geoengineering is to be implemented, there are also very important questions around governance, on the specific procedures, even on loss and damage policies around its use. There have been no demonstration projects to test its effects.

All these questions are still open, debate is still ongoing, so it will be somewhat premature to say that South Asia is ready for solar geoengineering.

Q: How important is it for voices from South Asia to be represented in global discussions on solar geoengineering?

South Asian countries are the most vulnerable to climate change. Understanding how they will be impacted due to climate change and climate change interventions is very important in this decade.

South Asia also have the most populous regions on Earth. They also have unique ecosystems, like high mountain ranges and deserts across several of the countries. 

The impacts on all these have to be known, otherwise progress will be very slow, just like in climate mitigation efforts today.

Q: What are your thoughts on whether the world needs solar geoengineering today?

Generally speaking, as far as science is concerned, all possibilities need to be considered in the fight against climate change. Solar geoengineering is one possibility – the most researched method now is sulfate injection into the atmosphere, but there are other techniques too.

There are also possibly unexpected or unwanted consequences of solar radiation management. For example, there could be acid rain. This technology does not contribute towards the reduction of carbon dioxide, nor help to address ocean acidification. So there needs to be some sort of balance.

Even those who are not much in favour of solar geoengineering do generally support research on it. By research, I’m referring to the numerical computer modelling we are doing today, and then with a better understanding in the future, conducting experiments.

There is already a large scientific community engaged on the topic.

Q: Some who are opposed to solar geoengineering say they are not confident that the world can have the high levels of cooperation needed to safely deploy solar geoengineering, based on the geopolitics today. What is your opinion on that?

Solar geoengineering is a global problem that needs to be solved globally. We can see some progress in global climate action, in carbon trading, carbon credits.

Again the very important message here is that solar geoengineering is not a complete solution, it reduces global warming without reducing carbon dioxide levels. It can perhaps buy us some time in climate mitigation, because progress is slow today, and like you mentioned, thereare large disparitiesin governance, finance et cetera.

Q: I’m wondering if solar geoengineering is something you would rather not have implemented, but that at this stage it is becoming inevitable that we will need the technology.

This is the right time to get engaged on solar geoengineering, and I have discussed with several think-tanks and policymakers in South Asia and Pakistan to get them familiar with the technology.

But there is still a communication gap here. We need to demonstrate what are the consequences to agriculture, a dominant part of the Indian subcontinent’s economy, for example. These impacts need to be known and communicated to policymakers, so that they know how solar geoengineering can fit into their plans on climate change mitigation.