Could A Giant Space Umbrella Solve The Climate Crisis?

Scientists are always concocting weird and wonderful ways to save the world – but we never thought a giant space umbrella would prove so promising. Here’s how these wacky plans could be the key to solving global warming.

Could A Giant Space Umbrella Solve The Climate Crisis?

Firstly: what would the giant space umbrella do? Solar umbrellas have been considered by scientists for a while now, as a way to reduce Earth’s temperature amid global warming by essentially plunging the planet into man-made shade.

The umbrella would have to be big enough that it stops solar radiation from reaching the Earth, and heavy enough that it balances gravitational forces and doesn’t float away – but such heaviness (we’re talking about 3.5 million tons, to be clear) creates new problems. How do we make it? And how on earth do we shoot it into space?

István Szapudi, an astronomer at the Institute for Astronomy at the University of Hawai’i, has an idea. In a new study published in PNAS, Dr Szapudi proposes balancing the hefty umbrella with a counterweight, which would make the total mass more than 100 times less.

OK, but where do we find a counterweight? And how do we launch both the umbrella and its counterweight into space? Dr Szapudi recommends tethering the umbrella to a captured asteroid – which would avoid having to launch most of the project’s mass from Earth. It sounds outlandish (it is outlandish), but the University of Hawai’i believes this idea could be developed into a workable design within decades.

At present, though this captured asteroid idea reduces the shield’s mass by about 100 times, the mass of the umbrella itself is far heavier than our current space launch capacities. When we say far heavier, we mean the umbrella is estimated to weigh in at 35,000 tons, while our biggest rockets can currently haul about 50 tons into low orbit.

‘In Hawai’i, many use an umbrella to block the sunlight as they walk about during the day,’ says Dr Szapudi. ‘I was thinking, could we do the same for Earth and thereby mitigate the impending catastrophe of climate change?’. Makes sense – and it’s thought that such a giant space umbrella could reduce the amount of solar radiation that comes to Earth by about 1.7 percent, which could be enough to prevent a catastrophic rise in temperatures.