Proposals to combat climate change trends by means of stratospheric aerosol injection are fraught with uncertainty. Large-scale projects to offset carbon dioxide-induced global warming may benefit some regions Regions where solar geoengineering applied to halve the warming produced by doubling CO2 moderates (blue) or exacerbates (red) the absolute magnitude of climate anomalies relative to control. Source: P. Irvine et al.Regions where solar geoengineering applied to halve the warming produced by doubling CO2 moderates (blue) or exacerbates (red) the absolute magnitude of climate anomalies relative to control. Source: P. Irvine et al.while adversely affecting others, and a lack of research and experimental evidence makes it difficult to predict the feasibility and effectiveness of climate engineering. To better understand the effects of solar geoengineering, the implications of smaller scale solar radiation management initiatives to reflect sunlight away from Earth were analyzed by researchers from MIT, Harvard University and Princeton University.

A high-resolution forecast-oriented low ocean resolution model was used to simulate extreme rainfall and tropical cyclones in different locations under scenarios assuming that solar geoengineering is applied to halve the warming produced by doubling CO2. Annual means of temperature, precipitation minus evaporation, yearly maximum temperature, yearly maximum precipitation in a five-day window and the power dissipation index of tropical cyclones were evaluated as key variables spanning most of the drivers of the key risks of climate change.

Relying on solar geoengineering to halve the warming produced by doubling CO2 was calculated to offset most of the related increase of simulated tropical cyclone intensity and to moderate changes in water availability and temperature. Less than 0.5% of the land would see the effects of climate change exacerbated, according to the model. The research, published in Nature Climate Change, supports an appreciable reduction in climate risk, without markedly greater risks to any region, due to this geoengineering approach.

To contact the author of this article, email shimmelstein@globalspec.com