Discuss the role of climate change in altering the frequency and intensity of extreme rainfall events like cloudbursts in India.

Q. Discuss the role of climate change in altering the frequency and intensity of extreme rainfall events like cloudbursts in India. (15 marks, 250-350 words)

The IMD defines a cloudburst as rainfall of 100 mm or more within an hour over roughly 20-30 sq. km [1]. Though such convective extremes are natural to India's orographic terrain, a warming atmosphere is measurably shifting their frequency, intensity and geography.

How warming alters extreme rainfall - A warmer atmosphere holds more moisture, so convective systems discharge it in shorter, sharper bursts. The IPCC AR6 records increased frequency and intensity of heavy precipitation over most of South Asia with high confidence, projected to intensify further beyond 1.5°C of warming [2]. - The MoES Assessment of Climate Change over the Indian Region found the frequency of daily rainfall extremes exceeding 150 mm/day over central India rose by about 75% during 1950-2015, even as mean monsoon rainfall declined — rain is compressing into fewer, more violent spells [3]. - Localised heavy rain occurrences across India rose during 1951-2015 [3].

Why the Himalaya bears the brunt - Orographic lifting of moisture-laden monsoon air over steep slopes triggers deep convection; IMD's analysis of five Uttarakhand cloudbursts in 2017 traced them to specific synoptic and thermodynamic setups [1]. - Recent disasters at Kishtwar and Mandi show the cascade — cloudburst to flash flood to landslide and debris flow — striking pilgrimage routes and hill settlements with thin evacuation capacity.

Climate change as multiplier, not sole cause - MoES attributes rising heavy-rain occurrences partly to urbanisation, land-use change and aerosols [3]; unregulated hill construction and blocked drainage convert a rainfall event into a fatality event. - Forecasting lags because the small footprint and hour-scale duration defeat coarse-resolution models; Mission Mausam (2024, ₹2,000 crore) is expanding the Doppler radar network from 39 towards about 126 [4].

Climate change is therefore best read as an amplifier acting on an already fragile Himalayan system. Denser radar coverage, hyperlocal nowcasting and enforcement of hill-town zoning together offer a workable path — aligning India's disaster response with SDG-13 on climate resilience.

(~320 words)

Sources: 1. Cloudburst events observed over Uttarakhand during monsoon season 2017 and their analysis, MAUSAM (IMD), 2022 — IMD cloudburst definition (100 mm/hour over 20-30 sq. km); synoptic and thermodynamic conditions behind Uttarakhand events 2. IPCC AR6 WG1, Chapter 11: Weather and Climate Extreme Events in a Changing Climate — increased heavy precipitation over South Asia with high confidence; intensification beyond 1.5°C 3. Assessment of Climate Change over the Indian Region, Ministry of Earth Sciences (2020) — ~75% rise in >150 mm/day extremes over central India (1950-2015); rising localised heavy rain; role of urbanisation, land use and aerosols 4. Mission Mausam: ₹2,000 crore initiative to enhance India's weather and climate forecasting, PIB (2024) — Doppler weather radar network expansion from 39 towards ~126