Portal:Climate change/Selected article/13
Pictured left: The albedo of several types of roofs.
Solar radiation modification (SRM) (or solar radiation management or solar geoengineering), is a group of large-scale approaches to limit global warming by increasing the amount of sunlight (solar radiation) that is reflected away from Earth and back to space. Among the potential approaches, stratospheric aerosol injection (SAI) is the most-studied, followed by marine cloud brightening (MCB); others such as ground- and space-based show less potential or feasibility and receive less attention. SRM could be a supplement to climate change mitigation and adaptation measures, but would not be a substitute for reducing greenhouse gas emissions. SRM is a form of climate engineering or geoengineering.
Scientific studies, based on evidence from climate models, have consistently shown that SRM could reduce global warming and many effects of climate change. However, because warming from greenhouse gases and cooling from SRM would operate differently across latitudes and seasons, a world where global warming would be offset by SRM would have a different climate from one where this warming did not occur in the first place. SRM would therefore pose environmental risks, as would a warmed world without SRM. Confidence in the current projections of how SRM would affect regional climate and ecosystems is low. Furthermore, a suboptimal implementation of SRM--such as starting or stopping suddenly, or intervening too strongly in the Earth's energy balance--would increase environmental risks.
SRM presents political, social and ethical challenges. A common concern is that attention to it would lessen efforts to reduce greenhouse gas emissions. Because some SRM approaches appear to be technically feasible and have relatively low direct financial costs, some countries could be capable of deploying it on their own, raising questions of international relations. Although some existing applicable governance instruments and institutions are applicable, there is currently no formal international framework designed to regulate SRM. Issues of governance and effectiveness are intertwined, as poorly governed use of SRM might lead to its suboptimal implementation. For these reasons and more, SRM is often a contested topic among environmentalists. (Full article...) (Full article...)