Climate change refers to any change in the climate over time, whether due to natural variability or as a result of human activity.
The IPCC defines climate change as it has been done above. This definition differs from the one made by the United Nations Framework Convention on Climate Change (UNFCCC). They have chosen to define climate change as: “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods”.
Our environment consists of many things, the climate being only one of them and this should not be mistaken for weather. Climate is generally defined narrowly as “average weather” and is usually calculated over an amount of years. According to The World Meteorological Organization (WMO), the usual time span is 30 years. “Average weather” generally consists of surface variables including temperature, precipitation and wind.
Climate can therefore broadly be defined as the state of the climate system calculated through average statistics.