Long-term shifts in global temperatures and weather patterns driven primarily by greenhouse gas emissions from burning fossil fuels. South Asia is among the most vulnerable regions.
climateWhat is Climate Change?
Climate change refers to long-term shifts in temperatures, rainfall patterns, ocean conditions, and atmospheric chemistry. While Earth’s climate has always changed over geological timescales, current climate change is occurring far faster than any natural change in millions of years, and is driven overwhelmingly by human activity.
The primary cause is the release of greenhouse gases — mainly carbon dioxide (CO₂) from burning fossil fuels (coal, oil, natural gas), methane (CH₄) from agriculture and waste, and nitrous oxide (N₂O) from fertiliser use. These gases trap heat in the atmosphere through the greenhouse effect, raising global average surface temperatures.
The numbers are unambiguous:
- Atmospheric CO₂: 280 ppm (1850) → 425 ppm (2026) — highest in 3+ million years.
- Global temperature: +1.2°C above pre-industrial average (and rising).
- Sea level: +21–24 cm since 1880; accelerating to 3.7 mm/year.
- Arctic sea ice: declined ~13% per decade since 1979.
- Mountain glaciers: net loss every year since 1980.
For South Asia, climate change is not a future concern — it is a current, observable, escalating crisis affecting 1.8 billion people.
How South Asia is changing
Temperature:
- Subcontinent-wide warming of 0.7°C since 1900, with the past three decades showing the fastest rise.
- Cities warm even more because urban heat islands amplify global warming locally — Delhi, Mumbai, Kolkata, Dhaka, Karachi have all warmed by 1.5–2°C.
- Himalayan warming is approximately double the global average — alarming for glacial water supplies.
Heatwaves:
- More frequent: a 1-in-50-year heatwave is now 1-in-5.
- More intense: 2022 and 2024 saw record-breaking pre-monsoon heat.
- Longer: heatwave durations extending from 4–5 days into 7–10 days.
- 2026 outlook: IMD projects above-normal heat over northwest India.
Monsoon:
- Total rainfall mostly unchanged, but concentrated into fewer, more intense events.
- More extreme rain days (above 150 mm in 24 hours) and longer dry spells between them.
- Western Disturbance behavior changing — winter rain pattern shifting.
Tropical cyclones:
- No clear trend in total numbers, but higher proportion intensifying to severe categories.
- More rapid intensification — cyclones strengthening from depression to severe in 24–48 hours.
- Higher rainfall within cyclones.
Sea level:
- Mumbai, Karachi, Chennai, Kolkata, Dhaka facing rising flood risk.
- Bangladesh delta projected to lose up to 17% of land area by 2050.
- Maldives existentially threatened.
Glaciers and rivers:
- Himalayan glaciers losing ~0.5% mass per year.
- Glacial lake outbursts (GLOFs) becoming more frequent — Sikkim 2023, Chamoli 2021.
- River flows projected to peak by 2050 then decline as glaciers shrink — major water security concern for the Indus, Ganga, Brahmaputra basins.
Air quality:
- Climate change interacts with pollution. Reduced rainfall fails to scrub PM2.5.
- More frequent stagnant air episodes intensify Delhi/Lahore winter smog.
Climate scenarios for South Asia
The IPCC AR6 projects under different emissions scenarios:
| Scenario | 2100 warming | Description |
|---|---|---|
| SSP1-1.9 (best case) | 1.0–1.8°C | Rapid net-zero by 2050 |
| SSP2-4.5 (moderate) | 2.1–3.5°C | Current policies extended |
| SSP5-8.5 (worst) | 3.3–5.7°C | High emissions, fossil-fuel intensive |
South Asia faces compounding effects:
- Land warming faster than oceans — already +1.5°C in northwest India.
- Wet-bulb temperatures approaching survivability limits in coastal cities.
- Glacial water peak followed by decline.
- Coastal inundation in deltas (Bangladesh, Sundarbans, Mumbai).
What South Asia is doing about it
India has committed to:
- Net-zero by 2070.
- 500 GW renewable energy by 2030.
- 50% non-fossil electricity by 2030.
- Major solar and wind expansion under PM-KUSUM and ISA.
Pakistan has committed to:
- 60% renewable energy by 2030.
- Tree plantation drives.
Bangladesh has committed to:
- Climate-resilient agriculture.
- Cyclone shelter expansion (world-leading evacuation system already).
- Mangrove restoration in the Sundarbans.
But emissions are still rising regionally. Coal still dominates India and Pakistan’s electricity mix. Per-capita emissions in South Asia remain below the global average — but total emissions are large because populations are large.
How climate change affects daily life
Even today, the impacts are felt by ordinary people:
- Heatwave deaths — 2025 saw 5,000+ heat-stroke deaths in India + Pakistan.
- Crop failures during erratic monsoon years.
- Power cuts during heatwave demand peaks.
- Higher AC costs as summer extends.
- Water rationing in cities — Chennai, Bengaluru, Delhi periodically.
- Health impacts from worse air quality.
- Climate migration — coastal Bangladeshis moving to Dhaka, Pakistani Sindhis after 2022 floods.
Adaptation strategies
South Asian cities and farmers are adapting through:
- Heat action plans — Ahmedabad’s plan has reduced heat mortality by 30%.
- Cyclone shelters — Bangladesh’s network of 14,000+ shelters.
- Climate-resilient crops — drought-tolerant rice, heat-tolerant wheat.
- Renewable energy — rooftop solar, microgrids.
- Urban tree planting — Hyderabad, Mumbai, Chennai initiatives.
- Coastal protection — sea walls, mangrove restoration.
- Insurance — PMFBY crop insurance, parametric weather insurance.
Frequently asked questions
Is climate change really happening, and is it caused by humans? Yes and yes. The scientific consensus — supported by 97%+ of climate scientists, the IPCC, every major scientific academy, and overwhelming observational data — is that the planet is warming at an unprecedented rate, and this warming is caused primarily by human greenhouse gas emissions.
Why is South Asia particularly vulnerable? Three reasons: (1) High exposure — densely populated coasts, monsoon-dependent agriculture, Himalayan water dependency; (2) High sensitivity — many people live close to climate thresholds; (3) Lower adaptive capacity — poverty, limited infrastructure.
Can we still avoid the worst climate change? The IPCC says yes — but only with rapid, deep, sustained emissions cuts. Limiting warming to 1.5°C requires global emissions to fall ~45% by 2030 and reach net zero by ~2050. Current policies put the world on track for ~2.7°C warming.
What can ordinary South Asians do?
- Reduce energy use; prefer renewable electricity.
- Buy efficient appliances (5-star BEE rating).
- Plant trees; protect existing forests.
- Reduce meat consumption.
- Take public transport, cycle, walk.
- Vote for climate-positive policies.
- Support local climate adaptation initiatives.
Where can I track climate-related weather events for my city? Mausam Online displays current and forecast weather, heatwave alerts, AQI and severe-weather codes on every city page. See Delhi, Mumbai, Karachi, Dhaka, Chennai.