Climate change refers to variation in the Earth’s climate and weather systems over thousands or even millions of years.
More recently, the term climate change has come to signify observable differences in the climate caused by human activity and the greenhouse gas effect. Climate change first entered colloquial language after the discovery of the hole above the Antarctic in the atmosphere’s ozone layer.
Since the 1990s we have become very aware of the impact humans are having on the planet through the release of carbon dioxide and other greenhouse gases from power stations, businesses, homes, vehicles and air travel. These effects range from the loss of polar ice to an increase in the average warmth of the world’s oceans and average surface temperatures.
The greenhouse effect, whereby heat is trapped in the atmosphere, has always been with us. Indeed, it is essential for sustaining life on Earth. But since the 1950s, this natural process - one that is credited with causing several extinction events in the ancient past - has been accelerated due to rising atmospheric concentrations of greenhouse gases, particularly carbon dioxide. This has triggered an international response led by the UN Framework Convention on Climate Change (UNFCCC), and further research under the auspices of the Intergovernmental Panel on Climate Change (IPCC).