A group of scientists from the Technion-Israel Institute of Technology has proposed an innovative solution to combat global warming—a set of sunshades sent into space to reduce incoming rays.
While the concept of using shields to block solar radiation has been under consideration for years, a team led by Technion Professor Yoram Rozen is now poised to construct and test a prototype of these shades.
In July 2023, astronomer Istvan Szapudi at the University of Hawaii suggested deploying a colossal shading layer, approximately 125 times the size of Israel or roughly the size of Argentina, to obstruct the sun's rays.
Building upon this idea, Rozen theorized that while a shade large enough to stabilize the climate would be excessively heavy and expensive for space launch, a series of smaller shades could be a slightly more affordable alternative, working in tandem to achieve the desired effect.
The calculations are based on the assumption that blocking just under 2 percent of the sun's radiation could cool Earth by 1.5 degrees Celsius (2.7° Fahrenheit), helping to maintain a manageable climate. Currently, the world is about 1° Celsius (33.8° Fahrenheit) warmer than pre-industrialization, according to the World Meteorological Organization.
The Technion's Asher Space Research Institute project, known as "Cool Earth," aims to position a shade at Lagrange Point One (L1), approximately 1.5 million kilometers (930,000 miles) from Earth. This point allows for a continuous shade provided by the shield.
In order to assess the feasibility of the sunshade project, the team is working on a technological demonstrator—an advanced satellite shield designed to control and diminish the amount of solar energy reaching Earth from the sun. Yoram Rozen, who played a role in designing the 2008 CERN "Big Bang" experiment, informed The New York Times that his team is prepared to construct a 100-square foot shade. The estimated cost for this prototype ranges between $10 million and $20 million, and it could be completed within three years. Success in this endeavor, he believes, would showcase the potential of the "full-size version"—a project with trillions in cost—that 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 to prove the "feasibility of the shading solution," according to the Asher Space Research Institute.
The satellite will have the ability to move toward the sun and back to Earth near L1 by controlling the shading sail, maintaining its position 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 reaching the Earth’s surface as needed.
This initial phase would serve as 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.