Asteroid tethered solar shield proposed to mitigate climate change

Earth’s rapid warming necessitates innovative solutions for mitigating climate change. Astronomer István Szapudi from the University of Hawaiʻi proposes a unique approach using a solar shield combined with a tethered asteroid as a counterweight to reduce sunlight reaching Earth. This ingenious solution significantly reduces the required mass and cost. Szapudi’s analogy of using an umbrella in Hawaiʻi to block sunlight inspired this idea. By engineering this approach now, we could work towards mitigating climate change within decades. The study titled “Solar radiation management with a tethered sun shield” is published in Proceedings of the National Academy of Sciences.

Incorporating a tethered counterbalance

Szapudi’s primary aim was to reduce solar radiation by 1.7%, a critical threshold to prevent catastrophic global temperature rise. His breakthrough came with the concept of using a tethered counterbalance towards the sun, which drastically reduced the total weight of the shield and counterweight to about 3.5 million tons – a significant improvement over previous untethered shield estimates.

Although the total weight remains challenging for current launch capabilities, only 1% (approximately 35,000 tons) would be the shield itself, making it the only part requiring launch from Earth. The rest, about 99% of the total mass, would consist of asteroids or lunar dust as a counterweight. This design makes it faster and more cost-effective to build and deploy compared to other shield designs.

Despite today’s largest rockets being capable of lifting only about 50 tons to low Earth orbit, Szapudi’s approach brings the idea closer to possibility, unlike prior concepts that were entirely unachievable. A key element in this plan is the development of a lightweight yet robust graphene tether, connecting the shield with the counterweight. This innovation holds the potential to revolutionize solar radiation management and aid in mitigating the effects of climate change.

Source: University of Hawaii at Manoa

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