CURRENT AFFAIRS | 12 MAY 2026
An IMD-anchored explainer (Indian Express, 12 May 2026) walks the reader through the climate phenomena likely to dominate India’s summer 2026: Western Disturbances, the three phases of ENSO (El Niño, La Niña, neutral), the IMD’s Heat Wave declaration criteria, and the increasingly cited concept of Wet Bulb Temperature — the threshold beyond which prolonged human exposure becomes physiologically lethal.
For CLAT 2027 candidates, this Environment + Geography piece is a triple-purpose anchor: it tests geography fundamentals, IPCC science vocabulary, and the environmental law framework (UNFCCC, Paris Agreement, India’s NDC, the Article 48A-21 jurisprudence).
Constitutional & Statutory Framework
India’s climate-environment legal scaffolding rests on four pillars: (i) Article 48A (DPSP, 42nd Amendment 1976) — State’s duty to protect and improve the environment and to safeguard forests and wildlife; (ii) Article 51A(g) (fundamental duty) — every citizen’s duty to protect and improve the natural environment; (iii) Article 21 — the SC’s recognition of the right to a clean and healthy environment as part of the right to life, beginning with Subhash Kumar v State of Bihar (1991) and M.C. Mehta v Union of India (multiple cases since 1986); and (iv) statutory anchors — Environment (Protection) Act 1986, the new Energy Conservation (Amendment) Act 2022 (carbon market), and the Climate Resilient Agriculture Mission framework.
At the international level, India is a party to the UNFCCC 1992, Kyoto Protocol 1997, and Paris Agreement 2015. India’s Updated NDC (August 2022) commits to: (a) reducing emissions intensity of GDP by 45% by 2030 from 2005 levels; (b) achieving 50% cumulative installed power capacity from non-fossil fuels by 2030; (c) net-zero by 2070.
Why CLAT 2027 Cares
This is a core Environment + Geography anchor. CLAT examiners love the trap on weather vs climate (short-term vs long-term), the El Niño → weak monsoon relationship, the precise IMD heat-wave thresholds (40 degree C plains, 37 degree C coast, 30 degree C hills), and the human-survivability threshold for Wet Bulb Globe Temperature (WBGT) of 35 degree C.
Equally testable: the IPCC AR6 (2021-23) finding that India is among the “highest-risk” geographies for heatwave intensification, and the SC’s recent M.K. Ranjitsinh v Union of India (2024) recognition of a fundamental right against the adverse effects of climate change — an explicit Article 14 + 21 reading.
Key Facts — Climate Terms Decoded
| Term | Definition / Threshold |
|---|---|
| Western Disturbance | Extra-tropical cyclone, originates over Mediterranean/Black/Caspian Seas; brings winter rain to North India |
| El Niño | Warming of central/eastern Pacific; weakens Indian monsoon |
| La Niña | Cooling of central/eastern Pacific; strengthens Indian monsoon |
| ENSO-neutral | Neither El Niño nor La Niña; SSTs near long-term average |
| Heat Wave (IMD plains) | Tmax ≥ 40 degree C AND departure 4.5-6.4 degree C for 2 consecutive days |
| Severe Heat Wave | Departure ≥ 6.4 degree C or Tmax ≥ 47 degree C in plains |
| Wet Bulb Temperature | Lowest temperature to which air can be cooled by evaporation at constant pressure |
| WBGT 35 degree C | Human survivability ceiling (Sherwood & Huber 2010) |
| India’s NDC 2022 | 45% emissions-intensity cut by 2030 (from 2005 baseline) |
Western Disturbances — The Mediterranean Connection
A Western Disturbance is an extra-tropical cyclone — not a tropical one. It originates over the Mediterranean, Black, or Caspian Seas, picks up moisture, and is steered eastward by the sub-tropical westerly jet stream. Between November and April, it brings winter rain to the Western Himalayas and parts of North India. The IMD has forecast a fresh Western Disturbance between 11 and 13 May 2026, expected to moderate the late-pre-monsoon heat across Delhi, Punjab, Haryana, and western UP.
ENSO — The Pacific Driver of the Indian Monsoon
The El Niño Southern Oscillation (ENSO) is a periodic oscillation of sea-surface temperatures in the central/eastern equatorial Pacific. Three phases: El Niño (warming, weakens Indian monsoon), La Niña (cooling, strengthens Indian monsoon), and neutral. The US Climate Prediction Center stated in April 2026 that ENSO-neutral conditions are currently prevailing, but El Niño is likely to emerge during May-July 2026 (61% probability) and persist till the end of 2026. IMD has factored this into its long-range monsoon forecast.
IMD Heat-Wave Criteria — The Numbers to Memorise
The IMD declares a heat wave when the maximum temperature departure from normal is 4.5-6.4 degree C, and the actual temperature is at least 40 degree C in plains, 37 degree C in coastal regions, or 30 degree C in hills, for 2 consecutive days. A severe heat wave is declared when the departure exceeds 6.4 degree C or the actual temperature exceeds 47 degree C in plains. The colour-coded warning system (Green-Yellow-Orange-Red) is issued jointly by IMD and the National Disaster Management Authority (NDMA).
Wet Bulb Temperature — The Lethality Threshold
Wet bulb temperature reflects what a human body can actually cool itself down to via sweat evaporation. A wet bulb of 35 degree C is considered the upper limit of human physiological tolerance — at this point, even a healthy person resting in shade with unlimited water cannot dissipate metabolic heat fast enough. A 40 degree C wet bulb day in Delhi can “feel like” 50 degree C+ on the dry-bulb scale, well into life-threatening territory.
Mnemonic for the Exam Hall
WD-ENSO-WBGT = Western Disturbances (winter rain from the West) + El Niño-Southern Oscillation (Pacific monsoon driver) + Wet Bulb Globe Temperature (survivability index).
IMD heat-wave numbers: 40-37-30 = plains-coast-hills (degree C). Departure: 4.5-6.4 for heat wave; ≥6.4 for severe. WBGT survivability: 35 degree C.
India’s NDC commitments (the “45-50-2070” trio): 45% emissions intensity cut by 2030 (from 2005), 50% non-fossil power capacity by 2030, 2070 net-zero target.
CLAT Probes Likely
- El Niño → weak monsoon → below-normal rainfall → agrarian distress (the causal chain).
- The 35 degree C wet bulb threshold and why it matters for India’s outdoor labour force (over 70% of NREGA work is outdoors).
- The legal status of India’s NDC under the Paris Agreement (Article 4) — politically binding, legally soft.
- SC’s M.K. Ranjitsinh v Union of India (2024) recognition of a fundamental right against climate change effects under Articles 14 and 21.
- Difference between weather (short-term, days-weeks, IMD) and climate (long-term, decades, IPCC).
Pair this with the recent CoP-30 at Belém (November 2025) negotiations on climate finance, where India and the G77 pushed for USD 1.3 trillion annually in developed-country contributions, and the operationalisation of the Loss and Damage Fund agreed at CoP-28 (Dubai, 2023). CLAT 2027 examiners will test the Common But Differentiated Responsibilities and Respective Capabilities (CBDR-RC) principle of the UNFCCC.
Practice Quiz — 10 CLAT-Style Questions
Click an option to reveal the answer and explanation.
