HQ Team
August 2, 2023: With global climate concerns at an all-time high, astronomer István Szapudi of the University of Hawaiʻi Institute for Astronomy has proposed an ambitious solution to combat climate change. The concept, known as the “Sun Umbrella,” involves utilizing an asteroid as a counterweight to a solar shield that would mitigate the amount of sunlight reaching the Earth’s surface
The Sun Umbrella Concept
At its core, the Sun Umbrella aims to cool the Earth by partially shading it from the Sun’s rays, a strategy known as solar radiation management. Unlike past proposals, which struggled with the immense weight required to balance gravitational forces and withstand solar radiation pressure, Szapudi’s Sun Umbrella introduces two groundbreaking concepts.
Firstly, Szapudi advocates for a tethered counterweight, replacing a massive shield, drastically reducing the overall weight by over a hundred times. Secondly, the proposal involves an asteroid as the counterweight, avoiding the resource-intensive process of launching such mass from Earth.
Drawing inspiration from the practical use of umbrellas for shade, Szapudi envisions shielding the Earth similarly to mitigate the impact of climate catastrophes. The primary objective is to reduce solar radiation by just 1.7%, a figure Szapudi believes could effectively prevent critical global temperature spikes.
Innovative Findings and Challenges
Szapudi’s research indicates that positioning a tethered counterweight towards the Sun could significantly reduce the combined weight of the shield and counterweight to around 3.5 million tons, a hundredfold lighter than a non-tethered shield.
The present launch capacities of spacecrafts are around 50 tons only. The proposal suggests launching only 1% of this weight, around 35,000 tons, as the shield itself. Advanced materials could further reduce the shield’s mass. The remaining 99% could consist of asteroids or lunar dust, simplifying construction and deployment.
The present launch capacities of spacecrafts are around 50 tons only. Szapudi’s concept brings solar radiation management within reach, an achievement that earlier ideas struggled to attain. The development of a strong yet lightweight graphene tether to connect the shield and counterweight becomes a pivotal aspect of this endeavor.
Context and Future Prospects
The concept of solar shields stems from geoengineering, exploring large-scale interventions to combat climate change. Solar shields emerged from observations of volcanic eruptions that create sunlight-reflecting haze, leading to temperature drops.
Solar shield designs till date include fleets of small sunshade spacecraft forming light-blocking clouds or massive orbital mirrors stationed at Earth-Sun Lagrange Point L1. Despite ongoing research, there’s no immediate plan for implementation due to technical, ethical, and sociopolitical challenges.
Szapudi’s innovative Sun Umbrella proposal represents a beacon of hope in the fight against climate change, offering a unique approach.
Szapudi’s innovative idea, was recently published in the Proceedings of the National Academy of Sciences.
