Solar geoengineering predicted to shift the risk of malaria in the tropics

Article content

* Chemical sunshades redistribute global malaria risk

* West Africa, South Asia and Amazon are at greatest risk

* Shifted transmissions will be added to the geoengineering debate

Alistair Doyle

Oslo, April 20 (Thomson Reuters Foundation) – Deploying a chemical haze over Earth to slow global warming – One controversial proposal to stop the effects of a deteriorating climate – Scientists said Wednesday could drastically change the spread of malaria in tropical regions.

Article content

One of the first studies to find out how “geoengineering” technology affects health was that artificial planetary awnings were deadly in hot lowlands such as West Africa, parts of South Asia, and the Amazon. We have discovered that it has the potential to further spread mosquito-borne illnesses. Basin.

In contrast, they can reduce the risk of the highlands of East Africa and the Indian subcontinent compared to a rapidly warming world without geoengineering, they write in the journal Nature Communications.

“It paves the way for both. Some countries will benefit and others will suffer,” said Mohammad Shafiul Alam, a malaria expert at the International Center for Diarrhea Disease Research in Bangladesh. Said.

Article content

As climate heating emissions continue to increase, some scientists, perhaps using a fleet of planes and rockets, spray small solar-reflected particles high up in the Earth’s atmosphere to create large planetary-cooled volcanic eruptions. Proposed to imitate.

Clouds of ash from the 1991 eruption of Mount Pinatubo in the Philippines have lowered global temperatures for over a year.

The potential for changes in malaria infections associated with the use of geoengineering is expected to add to the debate among developing countries on whether to proceed with malaria research.

Proponents say the technology could help prevent heat waves, droughts, floods and save lives more than ever if governments and businesses fail to keep their promises to curb temperature rises. increase.

Article content

However, some climate scientists and many environmental groups oppose the study of solar geoengineering.

They say it may be a slippery slope to a natural-threatening deployment of technology and may give fossil fuel producers and other pollutants an excuse to delay emission reductions.

Studies showing that the deployment of chemical solar shades can help some countries and hurt others can be controversial.

“A geoengineering strategy designed to offset warming is not guaranteed to unilaterally improve health outcomes and is often excluded from geoengineering conversations in the region among global tropical countries. It can create trade-offs, “writes a team of researchers from the United States, Bangladesh, and Germany. South Africa.

Article content

According to the World Health Organization, malaria caused by parasites that infect humans by infected mosquitoes killed 627,000 people in 2020, almost all of them in Africa. In 2020, an estimated 241 million malaria outbreaks worldwide.

The study found that transmission of the disease peaked at temperatures of 25 degrees Celsius (77 degrees Fahrenheit).

In tropical highlands such as Ethiopia and the Andes, solar geoengineering can help protect health by keeping temperatures below the permeation threshold.

However, in tropical regions such as western and central Africa and Indonesia, which are already approaching malaria limits, geoengineering can cool the climate and return it to a comfortable zone of illness, contributing to the spread of malaria.

Article content

“Difficult road”

Christopher Trisos, a research co-author at the University of Cape Town, said Earth’s geoengineering would be “a very difficult path to choose and even consider.”

Many studies investigating the risk of malaria in warmer worlds have shown how malaria can flow to developed countries such as Europe and North America, where health systems are more powerful and control. He said he was focusing.

“I wanted to see developing countries instead,” Trisos added.

The study did not consider the potential for improved health care in tropical countries by 2070, from vaccines to simpler measures such as mosquito nets.

In one extreme scenario, studies of climate and disease models have shown that more than 2 billion people in the world of geoengineering in 2070 may be at risk for malaria.

Article content

It’s comparable to just 1.25 billion to 1.5 billion in a world that is receiving rapid warnings, he said.

But “a world that is too hot for mosquitoes is also a world that is too hot for people. There is no benefit to catastrophic warming,” said Colin Carlson, a biologist at the Georgetown University Medical Center in Washington. I am saying.

He said reducing the emissions of fossil fuels that cause climate change should be “a moral imperative and save lives no matter what”, and geoengineering technology cannot replace that action. Stated.

“It’s difficult to decide whether to layer geoengineering on top of (emission cuts),” he said.

Jesse Reynolds, Executive Secretary of the World Commission on Climate Change Risk Management, welcomed the focus on developing countries and health.

Article content

But Reynolds, who wasn’t involved in the report, said it was “useless” to emphasize that geoengineering keeps people vulnerable to malaria, putting the world at many other risks due to rising temperatures. Said that he would face.

Members of his new committee will be announced in May, reviewing possible options for combating global warming beyond emission reductions and reporting in 2023.

Reynolds said this month’s UN Climate Scientist Commission report that global temperatures are “almost inevitable” beyond the goal set by the Paris Agreement to be 1.5 degrees Celsius higher than pre-industrial temperatures. Said.

The Intergovernmental Panel on Climate Change also said that it is “unavoidable” that countries need to absorb carbon dioxide from the atmosphere by planting trees and using special industrial machinery to reach their climate goals. rice field.

Article content

However, due to many uncertainties, solar geoengineering could not be supported.

Bangladeshi researcher Alam said that many consider solar geoengineering technology to be a kind of science fiction novel.

However, he pointed out that genetic modification of mosquitoes for breeding chironomids was also “long regarded as science fiction” and is now an established method.

“Perhaps another 20 years later, there will be increasing interest from policy makers to evaluate geoengineering,” he said.

(Reported by Alister Doyle, edited by Laurie Goering: (Acknowledge the credit of the Thomson Reuters Foundation, a charity of Thomson Reuters. Visit http://news.trust.org/climate)