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• Harvard researchers proposed a small-scale experiment that would spray aerosols into the atmosphere to reflect some sunlight back into space, a technology aimed at minimizing global warming. The experiment would measure the risks and effectiveness of the technology.
• The experiment is funded in part through Harvard’s Solar Geoengineering Research Program, and Bill Gates is among the donors to that program.
• The claim first surfaced in 2021 and has been previously debunked.
Bill Gates has been falsely accused of many villainous plans, from depopulating the Earth to pushing microchips as part of all medical procedures. Now, a recycled claim says Gates’ aims go even higher — literally.
"Bill Gates hatches 'horribly stupid' plan to block out the sun," says the headline on a Feb. 21 article on the Daily Star website.
The article was shared on Facebook and was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)
The falsehood centers on a small-scale experiment that Harvard researchers proposed — called SCoPEx, short for Stratospheric Controlled Perturbation Experiment — that would spray aerosols into the atmosphere to reflect some sunlight back into space, a technology aimed at minimizing global warming.
"Geoengineering is a blanket term for technologies that try to alter Earth’s physical qualities on the largest scale possible," Popular Mechanics reported. "One example is cloud seeding, where airplanes flush clouds with particulate matter in order to coalesce into rain."
Solar geoengineering involves using technology to try to reflect solar radiation back into space before it can interact with greenhouse gases. The most commonly proposed method is to use aerosols — "the gaseous clouds formed by particles of many common materials" — because the physical structure of their particles blocks and scatters light, according to Popular Mechanics.
The claim that solar geoengineering is an effort to "block out the sun" is inaccurate; the technology is a riff on a naturally occurring process. Already, about 30% of the sun’s energy is reflected back into space by clouds and ice, according to the Natural Resources Defense Council, an environmental nonprofit group.
But solar geoengineering is controversial, even according to the Harvard researchers who proposed the experiment. For one thing, the methods could have unintended consequences on global weather patterns.
The proposed Harvard experiment would use a high-altitude balloon to lift instruments into the atmosphere and release aerosols. The small-scale experiment is "to test the risks and efficacy" of solar radiation management, the researchers said, and to gather information that cannot be obtained through computer modeling and lab work.
As Popular Mechanics noted, "(A)ll of the scientists and backers involved are only suggesting doing research—not taking large-scale action."
Gates’ only connection to the research is through his donation to Harvard’s Solar Geoengineering Research Program, which is providing part of the funding for the project. Gates, who dropped out of Harvard in 1975 to co-found Microsoft, has provided funding to the university for climate research since 2007.
The article shared in the Facebook post also falsely claims that the experiment will "kick off in June." The project originally was scheduled to have a test flight in Sweden in June 2021, but a Harvard advisory committee delayed it until at least 2022 in order to study potential impacts.
An article headline says, "Bill Gates hatches 'horribly stupid' plan to block out the sun."
Gates did not create such a plan. He is among the donors to a program that’s funding a small-scale experiment proposed by Harvard researchers that would spray aerosols into the atmosphere to reflect sunlight back into space.
The experiment would measure the risks and effectiveness of the technology and is not an effort at widespread implementation.
We rate this claim False.
Daily Star, "Bill Gates hatches 'horribly stupid' plan to block out the Sun - just like Mr Burns," Feb. 21, 2022
David Keith’s Research Group, "Fund for Innovative Climate and Energy Research," accessed Feb. 25, 2022
Harvard’s Solar Geoengineering Research Program, "Funding," accessed Feb. 25, 2022
Keutsch Group at Harvard, "SCoPEx," accessed Feb. 25, 2022
National Academies of Sciences, Engineering and Medicine, "New Report Says U.S. Should Cautiously Pursue Solar Geoengineering Research to Better Understand Options for Responding to Climate Change Risks," March 25, 2021
Natural Resources Defense Council, "The Dept. of Solar Radiation Management," Jan. 25, 2015
Philosophical Transactions of The Royal Society, "Stratospheric controlled perturbation experiment: a small-scale experiment to improve understanding of the risks of solar geoengineering," 2014
PolitiFact, "No, Bill Gates did not outline 2018 plan to depopulate the planet," May 3, 2018
PolitiFact, "No, the Gates Foundation isn’t pushing microchips with all medical procedures," May 20, 2020
Popular Mechanics, "Bill Gates Will Have to Wait a While to Block the Sun," April 12, 2021
Popular Mechanics, "Bill Gates Is Thinking About Dimming the Sun," March 26, 2021
Poynter, "Claims that Bill Gates is going to ‘block the sun’ lack context," April 15, 2021
Scientific American, "Solar Geoengineering Should be Investigated, Scientists Say," March 26, 2021
Snopes, "Is Bill Gates Funding Efforts To Block The Sun?" Jan. 5, 2021
USA Today, "Fact check: Bill Gates is not trying to 'block the sun's rays' in the name of climate change," April 23, 2021
Wilson Center, "Solar Radiation Management," Sept. 20, 2020
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