It’s come to this. With Earth at its hottest point in history, and humans doing far from enough to stop its overheating, a small but growing number of astronomers and physicists are proposing a potential fix that could have leaped from the pages of science fiction: the equivalent of a giant beach umbrella, floating in outer space.
The idea is to create a huge sunshade and send it to a far away point between Earth and sun to block a small but crucial amount of solar radiation, enough to counter warming.Scientists have calculated that if just shy of 2% of the sun’s radiation is blocked, that would be enough to cool the planet by 1.5C and keep Earth within manageable climate boundaries.
The idea has been at the outer fringes of conversations for years. But as the climate crisis worsens, interest in sun shields has been gaining momentum, with more researchers offering up variations. A recent study led by University of Utah explored scattering dust deep into space, while a team at Massachusetts Institute of Technology is looking into creating a shield made of “space bubbles.” Last summer, Istvan Szapudi, an astronomer at the Institute for Astronomy at University of Hawaii, published a paper that suggested tethering a big solar shield to a repurposed asteroid.
Now scientists led by Yoram Rozen, a physics professor and the director of the Asher Space Research Institute at Technion-Israel Institute of Technology, say they are ready to build a prototype to show the idea will work. To block the necessary amount of solar radiation, the shade would have to be about 1 million square miles, roughly the size of Argentina, Rozen said. A shade that big would weigh at least 2.5 million tonnes – too heavy to launch into space, he said. So, the project would have to involve a series of smaller shades. They would not completely block the sun’s light but rather cast slightly diffused shade onto Earth, he said. Rozen said his team was ready to design a prototype shade of 100 square feet and is seeking between $10-$20 million.
Proponents say a sunshade would not eliminate the need to stop burning coal, oil and gas. Even if emissions from fossil fuels were to immediately drop to zero, there’s already excessive heat-trapping carbon dioxide in the atmosphere.
The idea also has its critics, who say it would be astronomically expensive and could not be implemented in time, given the speed of global warming. In addition, a solar storm or collision with stray space rocks could hurt the shield, resulting in sudden, rapid warming with disastrous consequences.
The idea is to create a huge sunshade and send it to a far away point between Earth and sun to block a small but crucial amount of solar radiation, enough to counter warming.Scientists have calculated that if just shy of 2% of the sun’s radiation is blocked, that would be enough to cool the planet by 1.5C and keep Earth within manageable climate boundaries.
The idea has been at the outer fringes of conversations for years. But as the climate crisis worsens, interest in sun shields has been gaining momentum, with more researchers offering up variations. A recent study led by University of Utah explored scattering dust deep into space, while a team at Massachusetts Institute of Technology is looking into creating a shield made of “space bubbles.” Last summer, Istvan Szapudi, an astronomer at the Institute for Astronomy at University of Hawaii, published a paper that suggested tethering a big solar shield to a repurposed asteroid.
Now scientists led by Yoram Rozen, a physics professor and the director of the Asher Space Research Institute at Technion-Israel Institute of Technology, say they are ready to build a prototype to show the idea will work. To block the necessary amount of solar radiation, the shade would have to be about 1 million square miles, roughly the size of Argentina, Rozen said. A shade that big would weigh at least 2.5 million tonnes – too heavy to launch into space, he said. So, the project would have to involve a series of smaller shades. They would not completely block the sun’s light but rather cast slightly diffused shade onto Earth, he said. Rozen said his team was ready to design a prototype shade of 100 square feet and is seeking between $10-$20 million.
Proponents say a sunshade would not eliminate the need to stop burning coal, oil and gas. Even if emissions from fossil fuels were to immediately drop to zero, there’s already excessive heat-trapping carbon dioxide in the atmosphere.
The idea also has its critics, who say it would be astronomically expensive and could not be implemented in time, given the speed of global warming. In addition, a solar storm or collision with stray space rocks could hurt the shield, resulting in sudden, rapid warming with disastrous consequences.
