Write a note on Global Warming.

Mechanism and evidence

• Carbon dioxide from fossil fuels and land-use change, methane from livestock, rice, and fossil leaks, nitrous oxide from fertilisers, and industrial fluorinated gases trap outgoing long-wave radiation — the enhanced greenhouse effect.
• The IPCC’s assessment cycles show that the post-1850 warming is not explained by solar or volcanic forcing alone; the last decade has been the warmest in the instrumental record.
• Observed signs include retreat of mountain glaciers, Arctic sea-ice loss, ocean heat content rise, and global mean sea-level rise from thermal expansion and ice melt.
• Extreme heatwaves, heavier short rains, and longer dry spells are the distributional face of the same mean warming, which is why ‘global warming’ is also a story of extremes.

India, equity, and response

• For India the risks are Himalayan glacier loss feeding the Ganga–Brahmaputra–Indus, monsoon irregularity, coastal flooding on the east and west, and heat stress on labour and wheat in the Indo-Gangetic plain, including Uttar Pradesh.
• The UNFCCC (1992), Kyoto Protocol (1997), and Paris Agreement (2015) frame common but differentiated responsibility; Paris asks for nationally determined contributions and a well-below-2°C / 1.5°C effort.
• India’s National Action Plan on Climate Change (2008) eight missions, later updates, and the 2021 Glasgow Panchamrit (500 GW non-fossil capacity, 50 per cent non-fossil electricity, 1 billion tonne emissions reduction, 45 per cent intensity cut, net-zero 2070) are the domestic note.
• Mitigation (coal peak, renewables, efficiency) and adaptation (heat action plans, climate-resilient agriculture, coastal regulation) must run together; a note that only names polar bears misses the Gangetic farmer.