Climate change

Climate change means big, long-lasting changes in climate, worldwide or in a region: shifts in temperature, rainfall and extreme weather.

For millions of years, natural processes changed the climate. But since the 1800s, the main cause has been people: burning fossil fuels, cutting down forests, harmful industry, and wasteful consumption.

Fossil fuels (coal, petroleum and natural gas) formed from the remains of plants and animals that died millions of years ago, buried deep under soil, rock or sea, where heat and pressure slowly changed them. We are burning in a few centuries what took millions of years to make.

Why does that matter? In nature, carbon dioxide and some other gases slowly enter the air and trap the Sun's heat. This natural greenhouse effect keeps the Earth warm enough for life. The problem is that industry, transport and farming have released huge amounts of these greenhouse gases in just a few centuries. The extra gas traps extra heat, causing fast global warming and upsetting the patterns that plants, animals and people are used to. The trouble is the speed.

India feels it: early in 2025, the country's average temperature was 1–3°C above normal, so winter was much shorter and milder, hurting farming and small industries.

Three words to know:

• resilience: being able to cope with, or recover quickly from, difficulties
• mitigation: steps to slow global warming and reduce its causes
• sustainable: something that can be kept going for a long time

Governments, including India's, promote mitigation: cutting greenhouse gases, planting trees, renewable energy, using energy efficiently, sustainable lifestyles. But these often clash with the wish for faster growth and more consumption. The answers are known; doing them is hard.