Introduction:
- The historic Paris climate agreement aims to keep global warming under 1.5 degrees Celsius (2.8 Fahrenheit) compared with pre-industrial times.
- However, the recent Emissions Gap Report warned the world would breach the warming mark of 2 degrees Celsius over the preindustrial era, even if the existing nationally determined contributions are delivered by 2030. One of the methods which can be used to quickly arrest this temperature rise is climate engineering.
- The Emissions Gap Report is United Nations Environment Programme’s (UNEP) spotlight report launched annually in advance of the annual Climate negotiations.
- The EGR tracks the gap between where global emissions are heading with current country commitments and where they ought to be to limit warming to 1.5°C.
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What is Climate Engineering?
- Climate engineering is a set of technologies that deliberately modify the Earth’s climate. Climate engineering is classified into two groups of techniques: Carbon dioxide removal (CDR), which removes and stores the emitted carbon dioxide from the atmosphere and solar radiation modification (SRM), which reflects sunlight back to space.
a) Carbon Dioxide Removal (CDR)
- CDR, which is expensive, involves five approaches. These include
- direct air capture,
- land-use management through afforestation/reforestation,
- sequestering carbon dioxide (CO2) produced by biomass,
- ocean fertilisation or the dumping of iron or urea to stimulate phytoplankton growth to absorb more carbon, and
- enhancing natural weathering processes that remove CO2 from the atmosphere.
Carbon Mineralization
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b) Solar geoengineering
- Solar geoengineering or solar radiation modification refers to technologies proposed to rapidly cool down Earth’s temperature.
- SRM approaches include increasing the surface reflectivity of the planet by painting structures with reflective paints, planting crops with high reflectivity, enhancing the reflectivity of marine clouds to reduce the amount of solar energy reaching the surface and removing infrared-absorbing clouds from the atmosphere to reduce trapped heat.
- Injecting aerosols into the lower stratosphere to mimic the cooling induced by volcanic eruptions and lowering the solar radiation reaching the Earth by placing reflectors or shields in space are some more SRM techniques.
Methods of Solar Geoengineering
- Among methods of solar geoengineering, proposals include simulating the cooling effects of volcanic eruptions, and enhancing the reflectivity of marine clouds.
- When volcanoes erupt, they spread into the atmosphere tiny particles, commonly known as “aerosols.” Light-colored aerosol particles can reflect incoming energy from the sun in cloud-free air and dark particles can absorb it. A small fleet of aircraft, for example, could conceivably inject sulfate aerosols or other reflecting particles into the stratosphere and drive large-scale cooling.
- Marine cloud brightening proposals entail using sea salt to stimulate the formation of low-altitude clouds over the ocean, enhance their reflectivity and extend their lifetimes.
- Other possible methods include sending a giant sunshade up into orbit and reducing heat-trapping cirrus clouds.
- Cirrus clouds are high, cold clouds composed of asymmetric ice particles.
- Thin cirrus clouds cause a net heating of the Earth because they allow visible sunlight to pass almost unhindered while at the same time absorbing and reradiating infrared radiation from the surface below.
- Albedo is a measure of how much light that hits a surface is reflected without being absorbed. The albedo value ranges from 0 to 1. The value of 0 refers to a blackbody, a theoretical media that absorbs 100% of the incident radiation. The albedo of Earth’s surface can be increased by increasing the surface reflectivity of the planet by painting structures with reflective paints, planting crops with high reflectivity.
Drawbacks of Geoengineering
- Geoengineering plans do nothing to change the underlying cause of climate change, the buildup of heat-trapping gases, i.e., they distract attention from the need for deep cuts to gross emissions which is achievable with the right political will and resource mobilization.
- However, research shows that using solar geoengineering could indirectly lower the amount of CO2 in the atmosphere by stemming permafrost melt, reducing energy-sector emissions and causing changes to the carbon-cycle feedback.
- Testing of geoengineering methods is required be done on a massive scale to truly understand their effectiveness in impacting the global climate which carries immense risks without knowing the potential harmful effects of such a large-scale deployment.
- Injecting sulfate aerosols in the stratosphere above the Arctic to mimic volcano clouds, for example, can disrupt the monsoons in Asia and increase droughts, particularly in Africa
- Climate geoengineering can exacerbate climate injustice by benefiting some regions while harming others, often disproportionately affecting countries in the Global South that are historically least responsible for climate change.
- Additionally, geopolitical tensions could arise if governments manipulate storms, potentially leading to accusations of acts of war when storms are redirected towards other countries.
Conclusion and way forward
- Geoengineering cannot be treated as a license to continue emitting more GHGs with no changes to current consumption and production patterns.
- Specific technologies that can help us achieve negative emissions need to be publicly funded (most obviously through the diversion of fossil fuel subsidies) and democratically administered to ensure that they serve the public interest. And they can only act as a supplement to scaling back of GHG emissions in all sectors, not a substitute.
- Besides, it is required that we should consider the risks and potential benefits of these technologies and make informed, well-governed decisions about further research and potential deployment.
References:
- https://www.unep.org/resources/emissions-gap-report-2023#:~:text=The%20Emissions%20Gap%20Report%20is,of%20the%20annual%20Climate%20negotiations.
- https://www.downtoearth.org.in/news/climate-change/must-assess-ethical-social-and-cultural-risks-of-climate-engineering-along-with-climate-action-unesco-report-93046
- https://www.downtoearth.org.in/news/climate-change/us-government-considers-controversial-solar-geoengineering-to-counter-global-warming-report-90364
- https://www.downtoearth.org.in/news/climate-change/can-geoengineering-help-fight-climate-change-scientists-think-so-64823
- https://www.downtoearth.org.in/blog/climate-change/why-geoengineering-is-still-a-dangerous-techno-utopian-dream-74828
Practice MCQs for UPSC Prelims:
- Consider the following technologies:
- Dumping of iron in the seas and oceans
- Injecting aerosols into the lower stratosphere
- Amplifying high-altitude cirrus cloud formation
- Augmenting albedo of earth’s surface
How many of the above technologies can be employed in climate engineering to reduce Earth’s temperature?
- a) Only one
- b) Only two
- c) Only three
- d) All four
Answer: c
Explanation:
- Climate engineering is a set of technologies that deliberately modify the Earth’s climate. Climate engineering is classified into two groups of techniques: Carbon dioxide removal (CDR), which removes and stores the emitted carbon dioxide from the atmosphere and solar radiation modification (SRM), which reflects sunlight back to space.
a) Carbon Dioxide Removal (CDR)
- CDR, which is expensive, involves five approaches. These include
- direct air capture,
- land-use management through afforestation/reforestation,
- sequestering carbon dioxide (CO2) produced by biomass,
- ocean fertilisation or the dumping of iron or urea to stimulate phytoplankton growth to absorb more carbon, and (Hence, point 1 is correct)
- enhancing natural weathering processes that remove CO2 from the atmosphere.
b) Solar Geoengineering
- Solar geoengineering or solar radiation modification refers to technologies proposed to rapidly cool down Earth’s temperature.
- SRM approaches include injecting aerosols into the lower stratosphere to mimic the cooling induced by volcanic eruptions and lowering the solar radiation reaching the Earth by placing reflectors or shields in space are some more SRM techniques. (Hence, point 2 is correct)
- Marine cloud brightening proposals entail using sea salt to stimulate the formation of low-altitude clouds over the ocean, enhance their reflectivity and extend their lifetimes.
- Other possible methods include sending a giant sunshade up into orbit and reducing heat-trapping cirrus clouds. (Hence, point 3 is not correct)
- Cirrus clouds are high, cold clouds composed of asymmetric ice particles.
- Thin cirrus clouds cause a net heating of the Earth because they allow visible sunlight to pass almost unhindered while at the same time absorbing and reradiating infrared radiation from the surface below.
- Albedo is a measure of how much light that hits a surface is reflected without being absorbed. The albedo value ranges from 0 to 1. The value of 0 refers to a blackbody, a theoretical media that absorbs 100% of the incident radiation. The albedo of Earth’s surface can be increased by increasing the surface reflectivity of the planet by painting structures with reflective paints, planting crops with high reflectivity. (Hence, point 4 is correct)
Hence, only three of the above technologies can be employed in climate engineering to reduce Earth’s temperature.
Therefore, option (c) is the correct answer.
Relevance: Climatic engineering can be helpful in keeping global warming under 1.5 degrees Celsius (2.8 Fahrenheit) compared with pre-industrial times.
Subject: Current Affairs | Geography
Level of Difficulty: Moderate | Factual
Practice Questions for UPSC Mains:
Q. What are the primary types and techniques of climate engineering, and what are the key challenges associated with their implementation and ethical considerations?