Substantial Climate Response outside the Target Area in an Idealized Experiment of Regional Radiation Management

[Geoeng Info]

https://www.mdpi.com/2225-1154/9/4/66

Substantial Climate Response outside the Target Area in an Idealized Experiment of Regional Radiation Management

Sudhakar Dipu

 ^1,* 

Johannes Quaas

 ¹ 

Martin Quaas

 ^1,2,

Wilfried Rickels

 ³,

Johannes Mülmenstädt

 ^1,4 and

Olivier Boucher

 ^5,6

¹

Institute for Meteorology, Universität Leipzig, 04109 Leipzig, Germany

²

German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, 04103 Leipzig, Germany

³

Kiel Institute for the World Economy Kiel, 24105 Kiel, Germany

⁴

Presently at Pacific Northwest National Laboratory, Richland, WA 99354, USA

⁵

Institut Pierre-Simon Laplace, Sorbonne Université, 75005 Paris, France

⁶

CNRS, 75016 Paris, France

Abstract

Radiation management (RM) has been proposed as a conceivable climate engineering (CE) intervention to mitigate global warming. In this study, we used a coupled climate model (MPI-ESM) with a very idealized setup to investigate the efficacy and risks of CE at a local scale in space and time (regional radiation management, RRM) assuming that cloud modification is technically possible. RM is implemented in the climate model by the brightening of low-level clouds (solar radiation management, SRM) and thinning of cirrus (terrestrial radiation management, TRM). The region chosen is North America, and we simulated a period of 30 years. The implemented sustained RM resulted in a net local radiative forcing of −9.8 Wm−2 and a local cooling of −0.8 K. Surface temperature (SAT) extremes (90th and 10th percentiles) show negative anomalies in the target region. However, substantial climate impacts were also simulated outside the target area, with warming in the Arctic and pronounced precipitation change in the eastern Pacific. As a variant of RRM, a targeted intervention to suppress heat waves (HW) was investigated in further simulations by implementing intermittent cloud modification locally, prior to the simulated HW situations. In most cases, the intermittent RRM results in a successful reduction of temperatures locally, with substantially smaller impacts outside the target area compared to the sustained RRM. View Full-Text