Study warns against using geoengineering to tackle climate crisis risks

A study published Wednesday in the journal Nature Communication warns that attempting to tackle the climate crisis using geoengineering – a method often promoted by the fossil fuel industry – could have the devastating consequence of exposing an additional billion people in countries vulnerable to malaria, a mosquito-borne disease.

“Simulations have revealed that a billion more people are at risk of contracting malaria in the world of geoengineering.”

The first of its kind study, compiled by a team of researchers from the United States, Bangladesh, South Africa and Germany, examines the potential global effects of using solar radiation management (SRM) to combat global warming. the strategylong viewed with skepticism by environmentalists and scientists, involves spraying aerosols into the atmosphere to reflect the sun’s rays away from Earth, providing a kind of “chemical umbrella.”

The research team used climate models to simulate possible malaria transmission in future scenarios with medium or high levels of global warming, and with and without geoengineering.

“In the medium and high warming scenarios”, the researchers found“Malaria risk was projected to shift significantly from region to region; but in the high warming scenario, simulations revealed that an additional billion people were at risk of malaria globally from geo-engineering.”

Colin Carlson, assistant research professor at Georgetown University Medical Center and lead author of the new study, mentioned that cooling the planet through geoengineering “could be an emergency life-saving option, but it would also reverse” recent declines in malaria transmission in the lowlands of sub-Saharan Africa, in Southeast Asia and other regions.

“If geoengineering is about protecting people on the front lines of climate change,” Carlson said, “we should be able to add up the risks and benefits, especially in terms of neglected health issues, such as mosquito-borne diseases”.

The study found that while some regions would likely see increased malaria transmission under the high warming and geoengineering scenario, other regions, such as the Indian subcontinent and the East African Highlands East, could see the risk of malaria decrease.

“It’s a two-way street: some countries will benefit and others will suffer,” said study co-author Mohammad Shafiul Alam, a malaria specialist at the International Center for Diarrheal Disease Research in Bangladesh. Told Reuters.

Scientists have long been concerned about the public health implications large-scale geoengineering, but the possible impact on the spread of specific diseases is understudied ground.

“The potential of geoengineering to reduce the risks of climate change remains poorly understood and could introduce a range of new risks to people and ecosystems,” said Christopher Trisos, senior researcher at the University of Cape Town in Africa. du Sud and one of the study’s new authors, said in a statement Wednesday.

Like Robinson Meyer, climate writer for Atlanticexplained in detail writing of the study, “The trade-off between geoengineering and malaria emerges for two reasons.”

He continued:

First, solar geoengineering does not perfectly wind up the Earth’s climate clock. Even if you add enough sulfate aerosols to perfectly counter warming from carbon pollution, you’re still changing the physics of climate, not restoring what once was. Many geoengineering simulations produce strange phenomena, such as “tropical supercooling”, in which land near the equator is colder than expected, even though land near the poles remains much warmer.

And that’s a problem, because malaria doesn’t have a linear relationship with temperature. The malaria parasite is spread by mosquitoes, which are cold-blooded and depend on ambient air temperature to regulate their metabolic rate; the risk of malaria therefore tends to increase as the temperature rises. It peaks at an average of 25 degrees Celsius, or 77 degrees Fahrenheit…

The study found that tropical overcooling and the ideal temperature for malaria transmission can interact in troubling ways. In some parts of the world, geoengineering has taken a location that would have been too hot for mosquitoes to survive and brought it back into a survival range. In others, it has restored the near 25 degrees Celsius temperatures that mosquitoes need to thrive.

Carlson argued that the findings should prompt closer examination of the unintended ripple effects of geoengineering methods, especially as governments view such programs as potential alternatives to the massive and rapid carbon emissions reductions that , according to scientists, are necessary to avoid the worst of the climate. emergency.

“The implications of the study for decision-making are significant,” Carlson said. “Geoengineering could save lives, but the assumption that it will also save everyone could put some countries at a disadvantage when making decisions.”

In 2019, the United States, then led by the Trump administration, joined Saudi Arabia and Brazil in blockage a United Nations resolution that called for a study of “potential transboundary risks and adverse effects of carbon dioxide removal and solar radiation management on the environment and sustainable development”.

Two years later, the Intergovernmental Panel on Climate Change (IPCC) published a report warning that “the side effects of any of the known geoengineering techniques can be very significant”.