Geoengineering for climate stabilization

Abstract

Engineering the climate by means of carbon dioxide removal (CDR), Earth radiation management (ERM), and/or solar radiation management (SRM) approaches has recaptured the attention of scientists, policy makers, and the public. Climate engineering is being assessed as a set of tools to deliberately, and on a large scale, moderate or retard global warming. There are several concepts available, like injecting aerosol-forming SO2 into the stratosphere or placing huge objects in orbit to partly shade Earth from incoming radiation or fertilizing the ocean with iron for increased algae growth and creation of carbon sinks. Such concepts are highly speculative, and irrespective of whether they would work, they bear huge risks, from adversely affecting the complex climate system on a regional or global scale to potentially triggering droughts, famine, or wars. More research is needed to better understand promising concepts and to work them out in depth, so that options are made available in case they should become necessary in the future, when climate change mitigation and adaptation measures do not suffice and fast action becomes imperative. Apart from the technological hurdles, which are anyhow mostly far beyond today’s engineering capabilities, huge social, moral, and political issues would have to be overcome. The purpose of this chapter is to highlight a few common concepts of CDR, ERM, and SRM for climate engineering to mitigate climate change.