What is climate change? A simple breakdown of the global crisis
- Climate change refers to long-term shifts in temperatures and weather patterns, primarily due to human activities like burning fossil fuels.
- Greenhouse gases such as carbon dioxide trap heat in the atmosphere, leading to global warming and extreme weather events.
- Impacts include rising sea levels, melting ice caps, and more frequent storms, floods, and droughts.
- Efforts to combat climate change focus on reducing emissions, switching to renewable energy, and adapting to unavoidable changes.
What exactly is climate change?
Climate change is the long-term alteration of temperature and typical weather patterns in a place. It is not the same as everyday weather, which can change from hour to hour or day to day. Instead, climate change refers to shifts that last for decades or longer.
Scientists have observed that the Earth's average temperature has been rising steadily since the late 19th century. This warming is closely linked to the increase in greenhouse gases in the atmosphere, mainly from human activities such as burning coal, oil, and gas.
Why is it happening now?
The main driver of modern climate change is the greenhouse effect. When sunlight reaches Earth, some of it is reflected back into space. But greenhouse gases like carbon dioxide (CO2) and methane trap some of the heat, preventing it from escaping. This keeps the planet warm enough for life to exist.
However, human activities have dramatically increased the concentration of these gases. The burning of fossil fuels for energy, transportation, and industry releases vast amounts of CO2. Deforestation adds to the problem because forests absorb CO2. The result is an enhanced greenhouse effect — more heat is trapped, causing global temperatures to rise.
Key greenhouse gases
- Carbon dioxide (CO2) — the most abundant long-lived greenhouse gas, primarily from fossil fuel combustion.
- Methane — from agriculture, livestock, and landfills. It is more potent than CO2 but shorter-lived.
- Nitrous oxide — from fertilisers and industrial processes.
- Fluorinated gases — man-made gases used in refrigeration and aerosols.
What are the effects?
Rising temperatures are already causing visible changes. Ice sheets in Greenland and Antarctica are melting faster, contributing to sea level rise. Glaciers in the Himalayas — a source of water for millions in India — are retreating. Extreme weather events, such as heatwaves, heavy rainfall, and cyclones, are becoming more intense.
In India, farmers face uncertain monsoons. Coastal cities like Mumbai and Chennai are at greater risk from storm surges and flooding. Around the world, coral reefs are bleaching, and species are shifting their ranges. The World Meteorological Organization says the past decade was the hottest on record.
What can be done?
Countries have agreed under the Paris Agreement to limit global warming to well below 2°C, preferably 1.5°C, compared to pre-industrial levels. This requires cutting greenhouse gas emissions drastically.
Solutions include shifting to renewable energy sources like solar and wind, improving energy efficiency, protecting forests, and developing technologies to capture carbon. Individuals can also help by reducing waste, using public transport, and choosing sustainable products.
But experts caution that action must be swift. The United Nations says emissions need to peak by 2025 and decline 43% by 2030 to keep the 1.5°C target alive.
Negotiations continue at annual climate summits. The next major milestone is the COP meeting later this year, where countries are expected to submit updated national plans to cut emissions.