A team of scientists at the Technion-Israel Institute of Technology have suggested a “cool” fix for global warming — a series of sunshades launched into space to dim some of the incoming rays.
While scientists have been kicking around the idea of shields to block solar radiation for years, an Israeli team led by Technion Prof. Yoram Rozen is now ready to build and test a prototype of one of the shades.
In July 2023, astronomer Istvan Szapudi at the University of Hawaii suggested launching a giant shading layer around 125 times the size of Israel — or roughly the size of Argentina — to block the sun’s rays.
Expanding on that idea, Rozen postulated that while a shade big enough to stabilize the climate would be far too heavy to launch into space and very expensive, a series of smaller shades would be slightly less expensive and could work together to create the desired effect.
The calculations are based on the established assumption that if just under 2 percent of the sun’s radiation is blocked, that would be enough to cool Earth by 1.5 degrees Celsius (2.7° Fahrenheit), which would keep the planet within manageable climate boundaries. The world is around 1° Celsius (1.8° Fahrenheit) warmer than before major industrialization, according to the World Meteorological Organization.
The Asher Space Research Institute project at the Technion, dubbed “Cool Earth,” aims to put a shade at the Lagrange Point One, also known as L1, a fixed point of about 1.5 million kilometers (930,000 miles) from the surface of the Earth where the gravitational forces from the sun cancel those from our plant. This means the shade provided by the shield would be continuous.
To test the viability of the project, the team is developing a first-of-its-kind technological demonstrator in which a satellite shield will be able to control and reduce the amount of solar energy that reaches the earth from the sun.
Rozen, who helped design the 2008 CERN “Big Bang” experiment, was quoted by The New York Times as saying that his team was ready to build a 100-square foot shade, which would cost between $10 million and $20 million and could be ready in three years. If all goes well, he said, it would demonstrate that the “full-size version” — which would cost trillions — could “reduce the Earth’s temperature by 1.5 [degrees] Celsius within two years.”
This prototype would be launched by a small spacecraft, reach L1 and deploy the shield in order to prove the “feasibility of the shading solution,” according to the Asher Space Research Institute.
The satellite will be able to move toward the sun and back to the Earth near L1 by controlling the shading sail, keeping it in place without the need for complex propulsion systems. By opening and closing the sail, it will also be possible to control the amount of solar energy that reaches the Earth’s surface as needed.
This would provide a template to scale up the project later.
“We at the Technion are not going to save the planet,” Rozen told The New York Times. “But we’re going to show that it can be done.”