Climate science
Global Warming
Definition
Global warming is the phenomenon of increasing average air temperatures near Earth's surface over the past one to two centuries. The IPCC's Sixth Assessment Report concluded that human activities, principally through emissions of greenhouse gases, have unequivocally caused global warming, with global surface temperature reaching about 1.1 °C above 1850–1900 in 2011–2020, and warming accelerating since 1975.
References
definition and magnitude
attribution and rate
Overview
What it means
Warming is not uniform: land warms faster than ocean, the Arctic fastest of all. Each increment raises the frequency and intensity of heatwaves, heavy precipitation, drought, and sea-level rise. The term is often used loosely as a synonym for climate change, though strictly it names the temperature rise itself, of which wider climatic changes are the consequence.
How it is used
The term anchors public communication, the Paris Agreement's temperature limits, and attribution science linking emissions to observed changes.
Why it matters
It is the master variable of the climate crisis: every mitigation target, carbon budget, and adaptation plan is calibrated against how much warming occurs.