Explained: Solar geoengineering and its impact on climate change
Global warming has increased significantly throughout the world as a result of rise in carbon dioxide concentrations in the atmosphere. Hence, efforts to combat global warming and the resulting climate change are primarily focussed on stabilising and subsequently reducing atmospheric carbon dioxide concentrations. Even in the best-case scenario, these tactics are only likely to generate results in the long run, after at least four to five decades.
Temperatures are likely to continue to increase in the meanwhile. Hence, scientists have been looking for alternate techniques to keep rising temperatures under control with more immediate effect. Placing artificial reflectors in the outer space – large mirrors or extremely small reflecting particles – to reflect back some of the solar energy impacting on the earth's surface is one of the ideas that has been investigated for a long time.
What is solar geoengineering?
Solar geoengineering is a term used to describe suggested methods for cooling the earth by reflecting solar radiation back into space. Scientists believe that we must reduce emissions of heat trapping gases quickly and drastically. They also emphasise the importance of removing carbon dioxide from the atmosphere in a safe and sustainable manner. Further, we need to invest more quickly to prepare for the effects of climate change.
What are the two main approaches of solar geoengineering being researched?
Stratospheric Aerosol Injection (SAI) and Marine Cloud Brightening (MCB) are the two primary approaches under consideration for solar geoengineering. Sulphate aerosol particles are excellent reflectors of sunlight. Many climate models have indicated that even if 1% of present incident solar radiation is reflected back into space, a significant amount of global warming can be avoided. However, if the SAI technique is implemented, it will have worldwide consequences, lowering temperatures and changing precipitation patterns all across the world.
On the other hand, marine cloud brightening, also known as marine cloud seeding and marine cloud engineering, is another proposed climate engineering method. It would brighten clouds by reflecting a small fraction of incoming sunlight back into space, thereby offsetting global warming. MCB is positioned as a potential alternative for dealing with worldwide environmental harm caused by extreme climate changes. It can be used for brief periods of time to regulate extreme temperature events and is not required to be utilised all year. Use of MCB technique can help in preventing long-term changes in weather cycles and atmospheric composition.
What are the concerns regarding solar geoengineering?
Solar geoengineering is a contentious concept that many people oppose since it involves not just science but also ethical and moral concerns. Unlike traditional techniques to dealing with climate change, geoengineering solutions do nothing to reduce carbon dioxide levels in the atmosphere, which are the primary cause of global warming. Solar geoengineering would not address the underlying causes of climate change, but it could help to slow it down. Initiatives to undertake small-scale atmospheric experiments are increasingly included in proposals and plans to expand solar geoengineering research. Since solar geoengineering has global ramifications, its consideration as a climate response necessitates competent international governance.