Climate change, disasters and sustainable development
What this domain tests
Expect questions on the greenhouse effect, the carbon budget, India's climate commitments, the disaster management cycle and the meaning of sustainable development. Maharashtra's hazard profile - drought, flood, heat and cyclone - supplies the case material.
Core concepts
- Greenhouse gases: CO₂, methane, nitrous oxide and fluorinated gases. Atmospheric CO₂ now exceeds 420 ppm against a pre-industrial 280 ppm.
- Global warming potential (GWP) compares gases over 100 years: methane about 28 times CO₂, nitrous oxide about 265 times.
- India's commitments: cut emissions intensity of GDP by 45% from 2005 levels by 2030, reach about 50% non-fossil installed power capacity by 2030, and net zero by 2070. Mission LiFE promotes household behaviour change.
- Sustainable development: the Brundtland definition - meeting present needs without compromising future generations - carried by the 17 SDGs.
- Disaster cycle: mitigation and preparedness before; response and relief during; recovery and reconstruction after. The Disaster Management Act, 2005, created NDMA, SDMA and district authorities; the Sendai Framework (2015–2030) sets global targets.
- Maharashtra hazards: the 26 July 2005 Mumbai deluge (944 mm in 24 hours at Santacruz), the 2019 Kolhapur–Sangli floods, recurring Marathwada drought, Vidarbha heat waves, and Cyclone Nisarga's June 2020 landfall near Alibaug.
Worked example
A landfill releases 50 kg of methane. With a GWP of 28, its CO₂-equivalent is 50 × 28 = 1,400 kg CO₂e, or 1.4 tonnes. GWP converts different gases to a common unit so one mitigation choice - capturing or flaring that methane - can be compared with, say, a solar installation on the same site.
Traps that cost marks
Saying the greenhouse effect is entirely man-made; without it Earth would average about −18 °C. Confusing mitigation (cutting emissions) with adaptation (adjusting to impacts). Mixing up the Sendai Framework with the Paris Agreement.