Climate change refers to a change in the average weather experienced in a particular region or location. The change may occur over periods ranging from decades to millennia. It may affect one or more seasons (e.g. summer, winter or the whole year) and involves changes in one or more aspects of the weather e.g. rainfall, temperature or winds. Its causes may be natural (e.g. due to periodic changes in the earth’s orbit, volcanoes and solar variability) or attributable to human (anthropogenic) activities e.g. increasing emissions of greenhouse gases such as CO2 and CH4, land use change and/or emissions of aerosols. However, ‘Climate change’ often refers to changes due only to anthropogenic causes.
Global warming refers only to the overall warming of the Earth, based on average increases in temperature over the entire land and ocean surface. Climate change is more than simply an increase in global temperatures; it encompasses changes in regional climate characteristics, including temperature, humidity, rainfall, wind, and extreme weather events, which have adverse economic and social impact.
Carbon-dioxide (CO2) emissions are the main contributor of global climate change. It is commonly acknowledged that, in order to avert the worst effects of climate change, the world must cut emissions as soon as possible, limiting warming to 1.5°C for manageable scenarios, at any degree higher than that, the impacts will be largely irreversible.