Spaceborne giant 'umbrella' proposed to combat global warming

In the pursuit of combating the impacts of global warming, scientists are exploring a groundbreaking concept: the creation of a spaceborne "umbrella" to shield our planet from the sun's rays.

Drawing inspiration from the use of umbrellas in Hawaii to block sunlight, István Szapudi, an astronomer at the University of Hawaii Institute of Astronomy, envisioned a similar approach for Earth's climate crisis. "Could we do the same for Earth and thus mitigate the impending climate change catastrophe?" he pondered.

The core issue driving global warming is the retention of sunlight by carbon dioxide and other greenhouse gases, preventing it from being released back into space. While these gases contribute to the problem, it's the sun's energy that initiates the heat accumulation. This realization has sparked the idea of constructing a protective shield for Earth.

Szapudi formulated his own version of an "umbrella." Positioned at the L1 Lagrange point between the sun and Earth, this shield would hypothetically join existing sun- and solar-wind-observing probes like the Solar and Heliospheric Observatory (SOHO) and Advanced Composition Explorer (ACE) already stationed there. The proposal envisions that a sufficiently large solar shield could effectively block about 1.7 percent of solar radiation at L1, thereby preventing a catastrophic temperature surge on Earth.

However, the engineering challenges for such a solar shade are formidable. The object stationed at L1 would experience gravitational forces from both the sun and Earth, while enduring a continuous stream of solar radiation. To be viable, the shade would need to be substantial—weighing millions of tons—and constructed from a robust material capable of enduring the conditions. Yet, launching such a massive structure into orbit is currently unfeasible.

To address this hurdle, Szapudi suggests that much of the material needed could be sourced from space itself, perhaps from a captured asteroid or lunar dust. This matter could potentially serve as a counterbalance, connected to a smaller shield weighing around 35,000 tons. Presently, even this reduced weight is beyond the capacity of available rockets. However, with advancements in material science, Szapudi's study indicates that accomplishing this feat within a few decades could be a possibility.