https://www.sciencedirect.com/science/article/abs/pii/S0094576522006762
*Authors* Olivia Borgue, Andreas M.Hein 10 December 2022 https://doi.org/10.1016/j.actaastro.2022.12.006 *Abstract* Limiting climate change to within the 2 °C limit requires net zero emissions of CO2 by 2050. However, the window of opportunity is closing fast. Geoengineering as the intentional and large-scale manipulation of the environment and the climate is increasingly discussed as a complement to ongoing mitigation efforts. As a particular geoengineering approach, space-based geoengineering proposes blocking or dissipating a fraction of incoming sunlight via a large number of occulting membranes, located close to the Lagrange 1 point between the Sun and the Earth. However, the mass of these sunshades, around 107–108 tons, and their deployment cost and effort render them about 10³ times more costly than terrestrial geoengineering alternatives. In this article, affordable sunshades, to be positioned close to L1 of the Earth-Sun system, are proposed, which are between 102 to 10³ times lighter than the lightest existing sunshade concepts. This is achieved via a nearly zero-radiation pressure design based on transparent refractive surfaces manufactured with ultra-thin polymeric films and SiO2 nanotubes. The lightest sunshade proposed in this article has a total mass of approximately 5.5 × 105 tons and its deployment requires between 859 and 399 annual launches during a ten year period. *Source*: ScienceDirect -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAOyeF5vxC2iyq6Mv%2BPNp%3DVuShgpaNqKSqJZJS73TBDZTgdefYw%40mail.gmail.com.
