Concern grows over rich nations controlling sunlight

By Sara Schonhardt | 03/10/2023 06:49 AM EST

Interest is building for limiting the sunlight that warms the Earth. But such climate intervention could have broad — and inequitable — impacts.

A woman fetches water during a drought in Samburu County, Kenya, in October.

A woman fetches water during a drought in Samburu County, Kenya, in October 2022. Brian Inganga/AP Photo

Radical climate interventions — like blocking the sun’s rays — could alter the world’s weather patterns, potentially benefiting some regions of the world and harming others.

That possibility, climate scientists say, means any research on such methods must consider those risks and involve the countries that already bear the greatest impacts from a warming planet.

“If you’re actually talking about actively deploying technologies to alter the climate, then you need to engage all of us in the discussion,” said Andrea Hinwood, chief scientist at the United Nations Environment Programme in Nairobi, Kenya. “And that means those who are the most vulnerable to these effects need to be able to have a say.”


The push for inclusive research comes alongside growing interest — and debate — over solar radiation management, a little understood way to avoid catastrophic climate change by injecting sunlight-blocking particles into the stratosphere or changing the density of clouds.

Climate scientists are, by and large, wary of such intervention. While limiting the amount of sunlight that reaches the Earth could rapidly cool the planet, they say, such efforts wouldn’t address ocean acidification and other harms associated with burning fossil fuels, the primary cause of global warming.

It’s also unclear how solar radiation management, or SRM, would affect global weather patterns, such as the monsoon rains that are crucial in some regions of the Global South. While it could ease climate impacts in one area of the world, SRM might reduce crop yields or threaten water supplies in another area.

Hinwood, who is originally from Australia, helped coordinate a report released last week that calls for regulations to manage SRM’s potential risks (Climatewire, Feb. 28). The report — written by independent experts and released by the U.N. Environment Programme — does not endorse SRM research. But it proposes guideposts for how any SRM research is conducted, with a focus on ensuring that the process is fair and equitable.

“This is about being cognizant the research is going on. So if it’s going to go on, let’s at least be very deliberate in the way that we consider it,” Hinwood said.

The aim, she said, is to advocate that “the research actually addresses the risks and uncertainties and the potential environmental, social and economic and other risks that may result from deployment in these technologies.”

Debate over the need for further research into SRM has grown as the world barrels toward breaking temperature limits that could result in a cascade of climate devastation.

Some proponents of climate action argue that SRM detracts from the need to reduce planet-warming pollution. Last year, a group of researchers called for a ban on what they call “solar geoenginnering” out of concern it could be used as an excuse to delay emissions cuts.

But efforts to curb the global demand for fossil fuels and other climate-harming resources aren’t happening fast enough.

Scientists and others who support more independent research say they don’t see SRM as a climate fix, nor do they support its deployment given how little is currently known about its impacts. They argue that more research is needed to understand how or even if it can be implemented safely — and that means taking a more inclusive approach to SRM studies.

“When we think about solar geoengineering, it is this inherently global thing, but regional impacts are going to look very different,” said Shuchi Talati, a scholar in residence with American University’s Forum for Climate Engineering Assessment.

“And so to be able to develop better scenarios, better inputs to those scenarios, and better questions around what to model, we need researchers from all over the world to be able to contribute to that to build a better understanding of potential impacts,” said Talati, who is forming a nonprofit focused on SRM governance and justice issues.

Tilting the balance of power

Homes are surrounded by floodwaters in Sohbat Pur, Pakistan, in August.
Homes are surrounded by floodwaters in Sohbat Pur, Pakistan, in August 2022. | Zahid Hussain/AP Photo

The Global North is home to most of the experts and institutions that conduct research into climate change — and to the funding to deploy new climate technologies.

That threatens to exacerbate the growing divide between the wealthy countries that have contributed most of the emissions warming the planet and the poorer ones forced to bear the resulting impacts in the form of more extreme storms, heat, droughts and rising seas.

“If the Global South is not included, any geoengineering activity has the potential to tilt the balance of power towards nations that are already powerful,” Govindasamy Bala, a professor at the Indian Institute of Science and an author of the UNEP report, said in an email.

He signed onto a letter last month urging more research into the viability of SRM approaches that brings in researchers from the Global South (Climatewire, Feb. 27).

SRM grabbed headlines late last year when a climate tech startup called Make Sunsets began unauthorized releases of sulfate-filled weather balloons in Mexico. When the Mexican government prohibited such efforts, Make Sunsets relocated to Nevada, where it has resumed its launches.

Wealthy philanthropists have also expressed support for SRM. That has raised concerns among experts that without international regulations governing the practice, anyone with enough money could unilaterally deploy it — with potentially grave consequences.

If a government or single entity deployed SRM without global consent, it could heighten geopolitical tensions, particularly in places where relations are already fraught. The Washington Post reported last month that U.S. national security officials are trying to better understand the challenges and how to manage them.

A country’s use of SRM could also detract from its climate commitments. And it could complicate discussions over how countries are compensated for the harms of global warming by making it difficult to determine whether so-called loss and damage is attributable to climate change or geoengineering.

“I looked at SRM as a response to loss and damage and SRM as a source of loss and damage, and I think we have to look at both and people are cognizant of both. But of course, it’s not binary,” said Neil Craik, a professor at the University of Waterloo in Canada who studies public international law.

More people from more places

It’s still too early to consider those implications, experts say. And it may never get to that point.

The UNEP report recommends a scientific review process based on models and observations that could guide potential research and future governance. If such an assessment determines that SRM deployment would lead to negative consequences, “consideration of deployment could be taken off the table,” the report concludes.

But even before that happens, more funding needs to go toward supporting research in the Global South, experts say.

The challenges are myriad. Researchers in the Global South often grapple with a lack of reliable electricity and internet access, and are often stretched thin, taking on multiple projects. Training can also be scarce.

But it really comes down to money, with most research in the Global South dependent on philanthropic funding.

That funding is “like a drop in the ocean” compared to what Europe, the United States and other wealthy countries contribute, said Christopher Lennard, an environmental scientist with the Climate System Analysis Group at the University of Cape Town in South Africa.

Lennard leads a team of researchers that received some funding from the nonprofit Degrees Initiative, which supports scientists in developing countries who use SRM modeling to understand the potential impacts on their local climate.

The Degrees Initiative was launched by Andy Parker, a former SRM researcher from England, in response to the Royal Society’s 2009 report “Geoengineering the Climate.” It now awards research grants to projects that model SRM impacts on things like drought in southern Africa or monsoon rainfall in India. So far, the nonprofit has awarded $1.8 million in grants through funding provided by Open Philanthropy, the European Climate Foundation and others.

The result is a community of scientists who don’t just research the effects of SRM but also can inform policy, ethics and governance should SRM deployment ever happen, Lennard said.

“Building up that community and that voice now for a discussion that might only take place in 10 years’ time is very important for us to do — so that we’re not just introduced to the discussion, we know nothing, and then can’t actually contribute to it in a meaningful way,” he said.

He and his research team are working to build up an impact-modeling community to understand what SRM might do to hydrology, agriculture, energy and health, since some parts of Africa are projected to suffer from severe heat stress as temperatures keep rising.

Impact research is an area that Talati, the scholar involved with SRM governance issues, thinks will be increasingly vital.

“But to be able to do the type of local and regional research that’s necessary for that, we’re going to need a lot more researchers, from a lot more places,” she said.

Reporter Corbin Hiar contributed.