Climate change
A lasting change in the average state or variability of the climate, observed over decades or longer.
Example
Human greenhouse gas emissions are the main cause of the warming observed since the mid-twentieth century.
The catch
One unusual day of weather cannot establish a long-term trend.
Related terms
Greenhouse gas, Albedo, Atmospheric lifetime, Carbon budget, Carbon dioxide, Climate feedback
In more depth
Climate change, explained.
Climate change reaches well beyond temperature, shifting rainfall, extremes and sea level, which makes it broader than global warming, the rise in average surface temperature. Scientists can now also judge individual events. Attribution studies estimate how much human influence changed the likelihood or intensity of a particular heatwave or downpour.
Definitions differ in one useful respect. The IPCC uses the term for any lasting change, whatever the cause, while the UNFCCC reserves it for change attributed to human activity on top of natural climate variability. When the cause matters to an argument, say which meaning you intend.