Climate Engineering Responses to Climate Emergencies

TL;DR

This paper reviews and evaluates shortwave climate engineering methods, especially stratospheric aerosol injection, as rapid responses to climate emergencies, proposing a research agenda to reduce uncertainties about their benefits and risks.

Contribution

It provides a structured technical review of SWCE, focusing on stratospheric aerosol injection, and develops frameworks for assessing climate engineering proposals.

Findings

Focused on stratospheric aerosol injection as a promising SWCE method.

Outlined a decade-long research agenda to evaluate benefits and risks.

Developed conceptual frameworks for assessing SWCE proposals.

Abstract

Despite efforts to stabilize CO_2 concentrations, it is possible that the climate system could respond abruptly with catastrophic consequences. Intentional intervention in the climate system to avoid or ameliorate such consequences has been proposed as one possible response, should such a scenario arise. In a one-week study, the authors of this report conducted a technical review and evaluation of proposed climate engineering concepts that might serve as a rapid palliative response to such climate emergency scenarios. Because of their potential to induce a prompt (less than one year) global cooling, this study concentrated on Shortwave Climate Engineering (SWCE) methods for moderately reducing the amount of shortwave solar radiation reaching the Earth. The study's main objective was to outline a decade-long agenda of technical research that would maximally reduce the uncertainty surrounding the benefits and risks associated with SWCE. For rigor of technical analysis, the study focused the research agenda on one particular SWCE concept--stratospheric aerosol injection--and in doing so developed several conceptual frameworks and methods valuable for assessing any SWCE proposal.