The recent attention Solar Radiation Management (SRM) is gaining as a potential strategy against global warming heralds the birth of an important era in climate research. The U.S. government has just published a report emphasizing the need for extensive risk-benefit assessments and a governance structure for SRM. This article will explore SRM in-depth, discussing its concept, methods, advantages and disadvantages.
What is Solar Radiation Management?
Solar Radiation Management entails a series of climate engineering efforts designed to mitigate global warming by deflecting a portion of the sun’s energy back into space before it can raise the Earth’s temperature. This concept, born out of desperation in the face of an escalating climate crisis, could have significant implications for human survival and the health of our planet.
Stratospheric Aerosol Injection (SAI): A Prominent SRM Method
SAI involves the dispersion of reflective particles like sulfate aerosols into the stratosphere. These particles scatter incoming solar radiation back into space, mimicking the cooling effect triggered by volcanic eruptions which also release aerosols into the stratosphere.
Marine Cloud Brightening (MCB): Another Approach in SRM
MCB comprises spraying fine seawater droplets or other substances into marine stratocumulus clouds that hover over oceans. These droplets act as nuclei for cloud condensation, boosting the reflectivity and longevity of these low-level clouds. This amplifies the cooling effect already provided by clouds which reflect approximately 20% of incoming solar radiation. Although MCB is more localized and reversible than SAI, it poses technical hurdles and is highly weather dependent.
Space Sunshades: An Advanced SRM Method
This technique entails positioning large mirrors or screens around the Earth or at a stable point between the Earth and the sun (Lagrange point 1), blocking or deflecting a portion of incoming solar radiation, thus reducing the amount of solar energy reaching the Earth’s surface. Despite being more controllable and adjustable than SAI or MCB, space sunshades are pricier, more complex to deploy, and challenging to maintain.
SRM: Potential Benefits
SRM holds promise for swift reduction in global temperatures, offering momentary relief from severe climate events. Depending on the technique and scale implemented, SRM could be cost-effective compared to other alternatives. Additionally, SRM strategies generally have short-term reversibility if they are halted or modified.
SRM: Potential Drawbacks
However, SRM is not a cure-all solution to climate change. It does not address problems like ocean acidification, biodiversity loss, or sea level rise due to thermal expansion. Moreover, it may also trigger negative or unintended side effects on regional or global climate systems, such as modifying precipitation patterns, influencing monsoons, droughts, storms, or crop yields. Ethical or geopolitical issues, such as creating winners and losers among countries or regions, raising questions of justice, equity, consent, liability, or responsibility, also pose potential challenges.
UPSC Civil Services Examination Previous Year Question (PYQ) Q. In the context of which of the following do some scientists suggest the use of cirrus cloud thinning technique and the injection of sulphate aerosol into stratosphere? (2019)
(a) Creating the artificial rains in some regions
(b) Reducing the frequency and intensity of tropical cyclones
(c) Reducing the adverse effects of solar wind on the Earth
(d) Reducing the global warming
Answer: (d)
Source: DTE
