Why is it in the news?
• As a tactic for addressing extreme ocean heat, the concept of marine cloud brightening is gaining prominence.
• Its main objectives are to reduce coral bleaching and ensure the protection of marine ecosystems.

About Marine Cloud Brightening
Historical Context
• The idea of cloud brightening traces back to 1990 and was proposed by British cloud physicist, John Latham.
• His goal was to control global warming by altering the Earth’s energy balance and counteract the warming resulting from a doubling of pre-industrial atmospheric CO2 levels.

Mechanism of Action
• In clean maritime air, larger droplets with lower light reflection form, primarily because clouds originate from relatively scarce sulphates and sea salt crystals.
• The main aim of MCB is to amplify the albedo or reflectivity of marine clouds.
• By using specialized vessels or water cannons, fine sea water droplets are released into the atmosphere.
• As these droplets evaporate, they leave behind salt particles, which serve as cloud condensation nuclei, paving the way for denser, more luminous clouds.

On Cloud Composition
• Warm clouds are characterized by numerous minuscule suspended water droplets.
• These droplets form around “aerosols,” which can either be of natural origin (like sea salt, ash, and pollen) or result from human activities like manufacturing and burning fossil fuels.
• Interestingly, a cloud with many small droplets appears brighter than a cloud with fewer but larger droplets, even if the total water quantity remains the same.

Potential of MCB
• MCB can strategically decrease sea surface temperatures in selected regions.
• It holds the promise of curbing the intensity and occurrence of coral bleaching episodes.
• Specifically, researchers are evaluating the potential of MCB for the Great Barrier Reef, which has suffered from mass bleaching events recently.

Human Involvement
• According to the Intergovernmental Panel on Climate Change, humans are already inadvertently participating in cloud brightening.
• Around 30% of the greenhouse gas-induced warming effect is offset by humanity’s unintentional aerosol emissions.
• Cloud trails known as “ship tracks” are visible because of the potent aerosols in ship exhaust, mainly sulphates.

Challenges & Risks of MCB
• Technical: Significant altitudes require the large-scale spraying of seawater, presenting intricate engineering challenges in terms of design, cost, maintenance, and operation.
• Environmental: MCB might lead to unintended alterations in precipitation and cloud patterns, which can impact the regional climate and might cause droughts or floods.
• Ethical & Governance: The decision-making processes and governance surrounding MCB implementation are contentious, as are the ethical ramifications of interfering with natural processes.
• Moral Hazard: There’s a potential risk that MCB might reduce the urgency to cut greenhouse gas emissions among the public and policymakers.

Conclusion
• MCB is in its developmental phase, necessitating further research to ascertain its governance, risks, feasibility, impacts, and efficiency.
• Rather than being a standalone solution, MCB is a possible short-term respite for coral reefs undergoing extreme heat stress.
• The broader strategy to combat climate change effects on coral reefs should integrate MCB with innovation, restoration, conservation, and adaptation.

Coral Bleaching

• Coral bleaching is when vibrant corals lose theirWhy is it in the news?
• As a tactic for addressing extreme ocean heat, the concept of marine cloud brightening is gaining prominence.
• Its main objectives are to reduce coral bleaching and ensure the protection of marine ecosystems.

About Marine Cloud Brightening
Historical Context
• The idea of cloud brightening traces back to 1990 and was proposed by British cloud physicist, John Latham.
• His goal was to control global warming by altering the Earth’s energy balance and counteract the warming resulting from a doubling of pre-industrial atmospheric CO2 levels.

Mechanism of Action
• In clean maritime air, larger droplets with lower light reflection form, primarily because clouds originate from relatively scarce sulphates and sea salt crystals.
• The main aim of MCB is to amplify the albedo or reflectivity of marine clouds.
• By using specialized vessels or water cannons, fine sea water droplets are released into the atmosphere.
• As these droplets evaporate, they leave behind salt particles, which serve as cloud condensation nuclei, paving the way for denser, more luminous clouds.

On Cloud Composition
• Warm clouds are characterized by numerous minuscule suspended water droplets.
• These droplets form around “aerosols,” which can either be of natural origin (like sea salt, ash, and pollen) or result from human activities like manufacturing and burning fossil fuels.
• Interestingly, a cloud with many small droplets appears brighter than a cloud with fewer but larger droplets, even if the total water quantity remains the same.

Potential of MCB
• MCB can strategically decrease sea surface temperatures in selected regions.
• It holds the promise of curbing the intensity and occurrence of coral bleaching episodes.
• Specifically, researchers are evaluating the potential of MCB for the Great Barrier Reef, which has suffered from mass bleaching events recently.

Human Involvement
• According to the Intergovernmental Panel on Climate Change, humans are already inadvertently participating in cloud brightening.
• Around 30% of the greenhouse gas-induced warming effect is offset by humanity’s unintentional aerosol emissions.
• Cloud trails known as “ship tracks” are visible because of the potent aerosols in ship exhaust, mainly sulphates.

Challenges & Risks of MCB
• Technical: Significant altitudes require the large-scale spraying of seawater, presenting intricate engineering challenges in terms of design, cost, maintenance, and operation.
• Environmental: MCB might lead to unintended alterations in precipitation and cloud patterns, which can impact the regional climate and might cause droughts or floods.
• Ethical & Governance: The decision-making processes and governance surrounding MCB implementation are contentious, as are the ethical ramifications of interfering with natural processes.
• Moral Hazard: There’s a potential risk that MCB might reduce the urgency to cut greenhouse gas emissions among the public and policymakers.

Conclusion
• MCB is in its developmental phase, necessitating further research to ascertain its governance, risks, feasibility, impacts, and efficiency.
• Rather than being a standalone solution, MCB is a possible short-term respite for coral reefs undergoing extreme heat stress.
• The broader strategy to combat climate change effects on coral reefs should integrate MCB with innovation, restoration, conservation, and adaptation.

Coral Bleaching

• Coral bleaching is when vibrant corals lose their colour, turning white, mainly due to stressors like elevated sea temperatures.
• This discoloration happens when the corals expel the symbiotic algae living in their tissues, leading to a loss of nutrients and colour.
• Bleached corals are weakened and become more susceptible to diseases. If the stressful conditions persist, it could lead to the death of the corals.
colour, turning white, mainly due to stressors like elevated sea temperatures.
• This discoloration happens when the corals expel the symbiotic algae living in their tissues, leading to a loss of nutrients and colour.
• Bleached corals are weakened and become more susceptible to diseases. If the stressful conditions persist, it could lead to the death of the corals.