What is a coastline?
A coastline is the area where land meets the ocean or sea. These areas can vary greatly in their geographical features, ranging from rocky cliffs and sandy beaches to expansive mangrove forests and estuaries.
How do coastlines vary globally?
Globally, coastlines are diverse. Some coastlines feature rugged cliffs and rocky shores, while others have wide sandy beaches. The ecological and geological characteristics of a coastline influence its vulnerability and resilience to environmental changes.
What are the primary threats to coastlines from climate change?
Climate change poses several major threats to coastlines, including:
Sea Level Rise: As global temperatures increase, glaciers and ice sheets melt, contributing to higher sea levels that can lead to flooding and erosion of coastal areas.
Increased Storm Intensity: Warmer ocean temperatures can intensify storms, leading to more severe storm surges and increased coastal damage.
Ocean Acidification: Increased CO2 levels lead to ocean acidification, which can degrade coral reefs and alter coastal marine ecosystems.
What is a Concurrent Heatwave and Extreme Sea Level (CHWESL) event?
A CHWESL event occurs when a heatwave and an extreme short-term sea level rise happen simultaneously at the same coastal location. This simultaneous occurrence can amplify the impacts of each individual event, posing increased risks to coastal infrastructure, ecosystems, and communities.
How have occurrences of CHWESL events changed over time?
Research indicates that occurrences of CHWESL events have increased between 1998 and 2017 compared to the preceding twenty years. This rise has been especially noted in tropical regions, where such events are becoming more frequent and intense.
Why are CHWESL events particularly dangerous?
CHWESL events are dangerous because they combine the hazardous impacts of heatwaves (such as health risks from extreme temperatures) with those of sudden sea level rises (such as flooding and coastal erosion). These combined effects can severely compromise public safety, damage property, and disrupt ecosystems.
What does the future hold for CHWESL events under climate change scenarios?
Studies project that under high emissions scenarios, such as the IPCC’s SSP5-8.5 scenario, CHWESL events may become five times more likely between 2025 and 2049. This suggests that global coastal areas could face significant challenges, including increased days of CHWESL conditions annually, impacting both human populations and the environment.
Understanding these dynamics is crucial for planning and implementing adaptation strategies to protect coastlines and the communities that depend on them.
► COASTAL CHALLENGES AND CLIMATE CHANGE: INDIAN CONTEXT
What are some examples of Indian coastlines facing environmental challenges?
India's extensive coastline, spanning over 7,500 kilometers across the mainland and its islands, encounters diverse environmental challenges exacerbated by climate change. Here are some significant examples:
Sundarbans, West Bengal:
Challenges: This region is notorious for its vulnerability to rising sea levels and increased cyclone activity. The Sundarbans, home to the world’s largest mangrove forest, faces severe threats from flooding and salinity intrusion, which jeopardize both biodiversity and local livelihoods that depend on agriculture and fishing.
Mumbai, Maharashtra:
Challenges: Mumbai’s coast is increasingly at risk of flooding due to high tides and storm surges. Urban sprawl and inadequate drainage exacerbate the risk during the monsoon season, leading to significant economic and human impacts.
Chennai, Tamil Nadu:
Challenges: Chennai has experienced substantial coastal erosion and waterlogging. The city's encroachment into coastal zones and wetlands reduces natural barriers, increasing vulnerability to storms and sea level rise.
Kerala Coast:
Challenges: Kerala's coast suffers from high rates of erosion, impacting densely populated regions. The 2018 floods in Kerala highlighted the additional risk of extreme rainfall events, which are likely to become more frequent and intense with climate change.
How do Concurrent Heatwave and Extreme Sea Level (CHWESL) events affect India?
India, with its high population density in coastal areas, is particularly susceptible to CHWESL events, which can lead to:
Public Health Emergencies: Extreme heatwaves coupled with flooding increase health risks, particularly heat-related illnesses and waterborne diseases.
Economic Disruptions: These events can disrupt economic activities, especially in ports and coastal cities integral to India’s economy.
Ecological Damage: Sudden sea level rises can cause saltwater intrusion into freshwater habitats and agricultural lands, leading to long-term ecological shifts and loss of biodiversity.
What steps is India taking to mitigate these risks?
India has initiated several measures to combat the effects of climate change on its coastlines:
Coastal Regulation Zone (CRZ) Notifications: These regulations aim to protect and conserve the coastline by restricting certain activities near the coast.
Integrated Coastal Zone Management (ICZM) Projects: These projects focus on improving coastal management practices, enhancing livelihood options, and preserving the coastal environment.
National Action Plan on Climate Change (NAPCC): The plan includes missions like the National Water Mission and the Green India Mission, which indirectly support coastal resilience by promoting sustainable water and forestry management practices.
Understanding and addressing the complex challenges posed by CHWESL events and other climate-related impacts are critical for safeguarding India's coastal regions and ensuring the safety and well-being of millions of people living in these vulnerable areas.
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