Global sea surface temperatures (SST)

GENERAL STUDIES-3
(TECHNOLOGY, ECONOMIC DEVELOPMENT, BIO-DIVERSITY, ENVIRONMENT, SECURITY AND DISASTER MANAGEMENT)

Why in News-

• Global Sea Surface Temperatures (SST) are a critical climate variable with profound implications for the environment, ecosystems, and human societies. Monitoring and understanding SST trends is crucial for assessing climate change and its cascading effects.

Importance of SST

• Climate Change Indicator:

• Rising SSTs serve as a key indicator of global warming. Oceans absorb a significant portion of excess heat trapped by greenhouse gases, reflecting changes in the Earth’s energy balance.

• Impact on Marine Ecosystems: Warmer waters disrupt marine habitats, leading to:

• • Shifts in species distribution and migration patterns.
  • Increased susceptibility to diseases.
  • Coral bleaching, damaging vital coral reef ecosystems.

• Ocean Circulation and Nutrient Cycling: Changes in SST influence:

• • Ocean circulation patterns.
  • Nutrient upwelling and mixing, essential for marine food webs.
  • Phytoplankton, zooplankton abundance, impacting fisheries and ecosystem health.

• Extreme Weather Events: Elevated SSTs contribute to:

• • Intensification of hurricanes, cyclones, and marine heatwaves.
  • Increased storm intensity, frequency, and precipitation, posing risks to coastal communities.

• Sea-Level Rise and Deoxygenation: Ocean warming leads to:

• • Thermal expansion of water, resulting in sea-level rise, threatening coastal regions.
  • Deoxygenation of marine environments due to reduced dissolved oxygen in warmer water, impacting marine life and ecosystems.

• Implications for Human Societies: Rising SSTs affect:

• • Food security, livelihoods, and cultural heritage in coastal communities dependent on marine resources.
  • Vulnerability to extreme weather events and sea-level rise, exacerbating risks of displacement, economic loss, and social disruption.

Why Rising Sea Surface Temperatures (SSTs) are a Cause of Worry

Impact on Marine Life: Warmer waters disrupt marine ecosystems by altering the distribution, abundance, and behavior of marine organisms. Many species, including corals, fish, plankton, and marine mammals, are highly sensitive to temperature changes. Rising SSTs can lead to:

• Coral Bleaching: Corals expel the algae that provide them with nutrients and color, turning white and eventually dying.
• Habitat Loss: As temperatures rise, suitable habitats for certain species shrink, forcing them to migrate or face population decline.
• Disrupted Migration Patterns: Changes in water temperature can disrupt the timing and location of migrations, impacting breeding and feeding grounds.
• Shifts in Species Composition: The distribution and abundance of various species can change, potentially leading to ecosystem imbalances.

Ocean Stratification and Nutrient Cycling: Rising SSTs contribute to:

• Stratification: Warmer, less dense surface water separates from cooler, denser deep water, hindering vertical mixing.
• Reduced Nutrient Cycling: Essential nutrients trapped in deeper layers become less available to phytoplankton, the base of the marine food web. This disrupts food webs and reduces overall productivity.

Marine Heatwaves (MHWs): More frequent and intense MHWs can have devastating consequences:

• Coral Bleaching: Similar to the effects described previously.
• Mass Mortality: Organisms unable to tolerate the heat may die in large numbers.
• Habitat Disruption: Marine habitats can be significantly altered, impacting entire ecosystems.

Extreme Weather Events: Elevated SSTs contribute to intensified extreme weather events:

• Hurricanes, typhoons, cyclones: Warmer oceans provide more energy to fuel these storms, leading to increased intensity, precipitation, and storm surges.
• Increased Risks: Coastal communities face greater threats from flooding, erosion, and property damage.

Sea-Level Rise and Coastal Vulnerability: Warming oceans contribute to:

• Thermal Expansion: As water warms, it expands, causing sea levels to rise.
• Melting Ice: Melting glaciers and ice caps add freshwater to the oceans, further accelerating sea-level rise.
• Increased Vulnerability: Coastal communities face greater risks of:
  • Inundation: Land being submerged by rising seas.
  • Erosion: Coastal shorelines being eroded by stronger waves.
  • Storm Surges: Coastal flooding due to a combination of high tides and storms.

Overall Impacts: Rising SSTs pose significant threats to:

• Marine Ecosystems: Biodiversity loss, disruptions to food webs, and ecosystem collapse.
• Coastal Communities: Displacement, loss of livelihoods, infrastructure damage, and social disruption.
• Global Climate Systems: Altered weather patterns, disruptions to ocean circulation, and potential for tipping points.

Addressing the Issue:

• Mitigation: Reducing greenhouse gas emissions to limit global warming is crucial.
• Adaptation: Building resilience in coastal communities and managing marine ecosystems for climate change.
• International Cooperation: Collective action is needed to address this global challenge.

Recommendations to Address Rising Sea Surface Temperatures (SSTs)

The urgency to act: Rising SSTs pose a significant threat to our planet. International cooperation and a multi-pronged approach are necessary to mitigate the issue and adapt to its consequences. Here are key recommendations:

• Adherence to Paris Agreement Goals: Limiting global warming to 1.5°C as outlined in the Paris Agreement is crucial. This can significantly reduce risks like drought, heat stress, and flooding. Achieving this target requires:
  • Global Commitment: All nations must cooperate and implement stricter emission reduction policies.
  • Transition to Low-Carbon Economy: Investments in renewable energy, energy efficiency, and phasing out fossil fuels are essential.
• Enhanced Efforts: Current policies are insufficient. We need to:
  • Strengthen Emission Reduction Targets: More ambitious goals are required to achieve well below 2°C warming.
  • Invest in Innovation: Research and development of clean technologies can accelerate progress.
• Expansion of Marine Protected Areas (MPAs): Protecting a wider ocean area:
  • Enhances ecosystem resilience to climate change.
  • Provides refuges for vulnerable species and habitats.
  • Offers opportunities for nature-based solutions like carbon sequestration.
• Balanced Mitigation and Adaptation: Both approaches are critical:
  • Mitigation: Focuses on reducing greenhouse gas emissions at the source.
  • Adaptation: Aims to build resilience and adapt to the inevitable impacts of climate change.

Ecosystem Restoration:

Restoring degraded ecosystems like:

• Forests
• Wetlands
• Mangroves
• Enhances carbon sequestration, removing CO2 from the atmosphere.
• Provides additional benefits like habitat protection and water purification.

The Way Forward:

• The likelihood of exceeding 1.5°C warming in the coming years highlights the urgency for action. By implementing these recommendations, we can work towards a more sustainable future for our oceans, coastlines, and the planet.

Additional Considerations:

• Public awareness campaigns to educate and mobilize individuals.
• Financial and technological support for developing nations to transition to cleaner energy sources.
• Research on climate change mitigation and adaptation strategies.
• By addressing rising SSTs through a comprehensive approach, we can build a more resilient future for generations to come.