Climate Change
Long-term shifts in Earth's average temperature and weather patterns, currently driven primarily by human emissions of greenhouse gases.
Climate change refers to long-term changes in Earth's average temperatures and weather patterns. While Earth's climate has shifted naturally throughout its history, the rapid warming observed since the late 19th century is overwhelmingly caused by human activities — particularly the burning of fossil fuels, deforestation, and industrial processes that release greenhouse gases like CO₂ and methane into the atmosphere.
The greenhouse effect itself is natural and necessary: gases like water vapour and CO₂ trap solar heat, keeping Earth at a livable temperature. But human emissions have raised atmospheric CO₂ from ~280 ppm pre-industrial to over 420 ppm today, causing global average temperature to rise by about 1.2°C.
Effects include rising sea levels, more frequent extreme weather, ecosystem disruption, glacial retreat, and ocean acidification. The IPCC (Intergovernmental Panel on Climate Change) regularly synthesises peer-reviewed research showing these trends with high confidence. Limiting warming requires rapidly reducing emissions and, eventually, removing CO₂ from the atmosphere at scale.