Innovative plan combines asteroid and sunshade to tackle climate change

Innovative plan combines asteroid and sunshade to tackle climate change
by Simon Mansfield
Sydney, Australia (SPX) Aug 01, 2023
As the Earth grapples with accelerating climate change, researchers are exploring a multitude of strategies to reduce global warming. Istvan Szapudi, an astronomer from the University of Hawaii Institute for Astronomy, has suggested a groundbreaking solution: a sunshade to lower the intensity of sunlight reaching Earth, paired with an asteroid acting as a counterweight. This unique proposal opens doors to immediate engineering studies to devise a practical design that could combat climate change in the forthcoming decades.

Shielding Earth from a portion of the sun's light, known as a solar shield, is a relatively simple way to decrease global temperatures. This isn't the first time such a concept has been suggested, but the immense weight required for a shield to balance gravitational forces and resist solar radiation pressure, leading to its potential drift, has previously rendered even the lightest materials exorbitantly costly. Szapudi's innovative proposal introduces two key improvements: the inclusion of a tethered counterweight to significantly decrease the required mass, and the use of a captured asteroid as this counterweight, circumventing the need to launch the majority of the mass from Earth.

Szapudi made an analogy to the common use of an umbrella for sun protection in Hawaii, asking, "could we do the same for Earth and thereby mitigate the impending catastrophe of climate change?"

Szapudi started his calculations with the goal of curtailing solar radiation by 1.7%, the amount scientists believe is necessary to avert disastrous global temperature increases. He determined that implementing a tethered counterbalance facing the sun could minimize the weight of the shield and counterbalance to around 3.5 million tons. This figure is nearly one hundred times lighter than former estimates for an untethered shield.

While this weight still vastly exceeds current launch capacities, a mere 1% of it-about 35,000 tons-would be attributed to the shield, the only part needing to be launched from Earth. With the advent of newer, lighter materials, the shield's mass could be further diminished. The rest, or 99%, would be asteroids or lunar dust serving as a counterweight. This tethered structure could prove to be faster and more cost-effective to construct and launch compared to previous shield designs.

Even though the largest rockets today can carry only about 50 tons to low Earth orbit, Szapudi's concept makes the idea of solar radiation management feasibly challenging. Prior concepts were utterly unattainable. The development of a lightweight, robust tether made from graphene, linking the shield and the counterweight, is also a pivotal aspect of this plan.

In essence, Szapudi's revolutionary approach combines the innovative use of a solar shield and a tethered asteroid, making the idea of mitigating the disastrous effects of climate change a potentially achievable goal. It not only brings the fight against global warming into the realm of reality but also underscores the power of creative thinking in addressing one of humanity's greatest challenges.

Research Report:"Solar radiation management with a tethered sun shield"