The Feasibility of Shading the Greenhouse with Dust Clouds at the Stable Lunar Lagrange Points

TL;DR

This paper explores the feasibility of using dust clouds at lunar Lagrange points as a space-based solar shading method to mitigate global warming, analyzing orbital stability and potential advantages over other approaches.

Contribution

It introduces a novel concept of dust cloud shading at lunar Lagrange points, analyzing orbital dynamics and stability for climate intervention.

Findings

Long-lived dust orbits are possible near Lagrange points.

Dust grain size affects orbit stability and phase space volume.

The scheme offers potential advantages and disadvantages compared to other solar shading methods.

Abstract

There are many indications that anthropogenic global warming poses a serious threat to our civilization and its ecological support systems. Ideally this problem will be overcome by reducing greenhouse gas emissions. Various space-based methods, including large-scale solar shades, diffusers or atmospheric pollutants, have been considered to reduce the solar constant (input flux) and the warming in case emissions reductions are not achieved in a timely way. Here it is pointed out that proposed technologies for near-Earth orbiting comet deflection, suggest a different kind of space-based solar shade. This shade would be made up of micron-sized dust particles derived from comet fragments or lunar mining, and positioned in orbits near the triangular Lagrange points of the Earth-Moon system. Solar radiation pressure can render such orbits unstable, but a class of nearly resonant, and long-lived orbits is shown to exist, though the phase space volume of such orbits depends on dust grain size. Advantages and disadvantages of this scheme relative to others are considered.