Microsoft co-founder Bill Gates has invested millions of dollars in research exploring ways to cool the planet by blocking a portion of sunlight from reaching Earth.
The development comes just over a month after Gates expressed interest in launching dedicated agriculture projects in Pakistan, an announcement that faced strong public criticism from Pakistanis.
The technology, known as solar geoengineering, involves reflecting a portion of sunlight back into space to reduce global temperatures.
One of the most widely discussed approaches involves releasing tiny reflective particles high into the atmosphere. These particles would reduce the amount of solar radiation reaching Earth’s surface, producing a cooling effect similar to that observed after major volcanic eruptions.
How Bill Gates Is Funding the Research
Gates is among the backers of Harvard University’s Solar Geoengineering Research Program, established in 2017. The initiative has also received funding from the Hewlett Foundation and the Alfred P. Sloan Foundation.
The full extent of Gates’ financial contributions to solar geoengineering research has not been publicly disclosed.
The Harvard program previously supported SCoPEx, an experimental project designed to release small quantities of reflective particles from a high-altitude balloon to examine their behaviour in the atmosphere.
However, Harvard discontinued the experiment in March 2024 following delays and public opposition. Research into solar geoengineering has continued through other initiatives.
Gates Not Pushing for Sunlight Blocking
Gates has distinguished between researching solar geoengineering and actually deploying the technology.
In an interview with Axios in December 2025, he said he would only support its use if the world reached dangerous climate tipping points.
“No way am I pushing the world in that direction,” Gates said, while arguing that understanding the technology could still prove valuable.
He has also highlighted the risks of relying on sunlight-blocking technologies. Such an approach could weaken efforts to reduce fossil fuel consumption, while scientists still lack a complete understanding of its effects on rainfall and regional weather patterns.
Why Scientists Are Concerned
Solar geoengineering remains highly controversial because changing the amount of sunlight reaching Earth could have consequences beyond lowering temperatures.
Researchers have warned about potential damage to the ozone layer, increased air pollution, and disruptions to rainfall and weather patterns in different parts of the world.
There are also concerns that changes in atmospheric conditions could benefit some regions while exposing others to droughts and other climate-related risks.
Gates has also been involved in Pakistan through agriculture-related initiatives and financial support for flood relief. However, his recent interest in launching dedicated agricultural projects in the country has attracted considerable public criticism.
