A study published WednesdayThe journal Nature Communications warns that attempting to fight the climate crisis using geoengineering — a method often promoted by the fossil fuel industry — could have the devastating consequence of exposing a billion additional people in vulnerable countries to the mosquito-borne disease malaria.
This is the first-of-its kind studyThe following report, which was compiled by researchers from the U.S. and South Africa, examines the global potential effects of solar radiation management (SRM), to combat planetary heating. The strategy, long viewed with skepticism by environmentalists and scientists, involves spraying aerosols into the atmosphere to reflect solar rays away from Earth, providing a kind of “chemical sunshade.”
The research team used climate models to model possible malaria transmission in future scenarios of high or low global warming and with or without geoengineering.
“In both medium- and high-warming scenarios,” the researchers found, “malaria risk was predicted to shift significantly between regions; but in the high-warming scenario, simulations found that a billion extra people were at risk of malaria in the geoengineered world.”
Colin Carlson is an assistant professor of research at Georgetown University Medical Center. He is the principal author of the new study. said that cooling the planet through geoengineering “might be an emergency option to save lives, but it would also reverse course” on recent malaria transmission declines in lowland sub-Saharan Africa, southern Asia, and other regions.
“If geoengineering is about protecting populations on the frontlines of climate change,” said Carlson, “we should be able to add up the risks and benefits — especially in terms of neglected health burdens, such as mosquito-borne disease.”
The study found that while some areas would likely see malaria transmission increase under the high-warming, geoengineered scenario, other regions — such as the Indian subcontinent and the highlands of East Africa — could see malaria risks decline.
“It cuts both ways: some countries will benefit and other countries will suffer,” study co-author Mohammad Shafiul Alam, a malaria specialist at the International Center for Diarrhoeal Disease Research in Bangladesh, told Reuters.
Geoengineering is often seen as a tool to promote climate justice. Our new study today @NatureCommsThis idea is challenged by the fact that solar geoengineering could lead to regional tradeoffs and possibly an increase in malaria risk worldwide. (1/4)https://t.co/tckv88HIL0 pic.twitter.com/55hhbFhjcX
— Colin J. Carlson (@wormmaps) April 20, 2022
Scientists have been raising concerns about the effects of radiation on human health for a long time. public health implications Geoengineering at large scales, but the potential impact on specific diseases is not well understood.
“The potential for geoengineering to reduce risks from climate change remains poorly understood, and it could introduce a range of new risks to people and ecosystems,” Christopher Trisos, a senior researcher at the University of Cape Town in South Africa and one of the new study’s authors, said in a statement Wednesday.
Robinson Meyer is a climate journalist The AtlanticThis is explained in detail by his write-up of the study, “The trade-off between geoengineering and malaria emerges for two reasons.”
He continued:
First, solar geoengineering doesn’t perfectly turn back the clock on Earth’s climate. Even if you add enough sulfate aerosols to perfectly counteract the amount of warming from carbon pollution, you’re still changing the climate’s physics, not restoring what once was. Many geoengineering simulations produce strange phenomena, such as ‘tropical overcooling,’ wherein land near the equator is cooler than you would expect, even while territory near the poles remains much hotter.
And that’s a problem, because malaria does not have a linear relationship with temperature. The malaria parasite is spread through mosquitoes that are cold-blooded. They rely on the temperature of the air to regulate their metabolism. As a result, the risk of contracting malaria increases as the temperature rises. It peaks at an average of 25 degrees Celsius, or 77 degrees Fahrenheit…
The study showed that tropical overcooling can cause malaria transmission to occur in dangerous ways. Geoengineering brought back mosquito survival in some areas of the world that would have been too hot for them. In others, it restored the close-to-25-degree-Celsius temperatures that mosquitoes need to thrive.
Carlson suggested that these findings should prompt a closer look at the unintended ripple effect of geoengineering methods, especially as governments consider such schemes. potential alternatives to the rapid and massive reductions in carbon emissions scientists say are needed To prevent the worst effects of the climate emergency.
“The implications of the study for decision-making are significant,” Carlson said. “Geoengineering might save lives, but the assumption that it will do so equally for everyone might leave some countries at a disadvantage when it comes time to make decisions.”
In 2019, the U.S. — then led by the Trump administration — joined Saudi Arabia and Brazil in blocking a United Nations resolution that called for a study of the “potential transboundary risks and adverse impacts of carbon dioxide removal and solar radiation management on the environment and sustainable development.”
Two years later the Intergovernmental Panel on Climate Change, (IPCC), was formed. released a report warning that “the side effects of any of the known geoengineering techniques can be very significant.”
