Why in the news?
- A recent study shows an increase in cyclone and flood events in the south and southeast Asia due to the influence of climate change and deforestation.
Cyclone
- What is it?: A cyclone is a large-scale atmospheric system characterized by inward-spiraling winds rotating around a center of low pressure. Cyclones rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere due to the Coriolis effect.
Cyclone in South and Southeast Asia
- Role of Climate Change:
- Global Warming Effect: World ~1.3°C warmer since mid-1800s; atmosphere holds ~7% more moisture per 1°C rise, intensifying rainfall.
- Sri Lanka: 5-day heavy precipitation 28-160% more intense.
- Malacca Strait (Indonesia/Malaysia): Extreme rainfall up 9-50%.
- Sea Surface Temperatures (SSTs): North Indian Ocean SSTs 0.2°C above 1991-2020 average during storms
- Limitations: Precise climate change attribution challenging due to El Niño-Southern Oscillation and data gaps.
- Global Warming Effect: World ~1.3°C warmer since mid-1800s; atmosphere holds ~7% more moisture per 1°C rise, intensifying rainfall.
- Role of Deforestation:
- Causing Accelerated runoff, higher flood peaks, landslides killing. E.g.: Sri Lanka
- Reduced flood barriers, slope instability in Sumatra and intensified floods/landslides in Indonesia.
- Role of Urbanisation:
- Increased Exposure: More people, roads, railways, cropland in flood-risk zones in Sri Lanka and Indonesia.
- Vulnerabilities: Informal housing, service failures, poor land-use planning.
Source: Indian Express