Intervening on Earth's climate through heliotropic dust rings and dust cloud at the L1 Lagrange point

Abstract

If it were to become evident that dangerous changes in global climate were inevitable, despite reducing greenhouse gas emissions, active strategies to avoid climate change in the Earth on an emergency basis might be useful. Several space-based methods to date regarding the reduction of solar insolation, including shading the Earth with a particle ring, or shading the Earth with solid reflectors or refractors, have been considered to reduce the solar radiation and the warming in case emissions controls are not enough. In this study, two methods of geoengineering are proposed to intervene on Earth's climate, involving Sun-pointing elliptical Earth ring comprised of dust grains, and clouds of dust placed in the vicinity of the L1 point, such that a set of orbits around the Earth and near L1 shall be characterized to prevent future natural climate variability, and producing a modest global temperature decrease. In the first scenario around the Earth, families of non-Keplerian periodic orbits will be explored, taking into account the effects of solar radiation pressure and the Earth's J2 oblateness perturbation. Analytical and numerical models will be considered to predict the orbit evolution of the dust ring due to solar radiation pressure and the J2 effect. In the second scenario around L1, the dust cloud will be assumed to be moving under the influence of the gravitational forces due to the Sun and the Earth. In addition, because of the small scale of the dust particles considered in this scenario, solar radiation pressure, Poynting-Robertson effect, interactions with the solar wind and the Lorentz force will be taken into account. (AU)