Explaining climate change
What is climate change?
Climate is the average weather experienced over a long period of time, which includes temperature, wind and precipitation (rainfall, hail, sleet and snow). The Earth’s climate is not fixed and in the past has changed many times in response to a variety of natural causes.
Climate change refers to an identifiable change in the climate that persists for an extended period, typically decades or longer, and is often taken to mean man-made changes that have occurred since the onset of the industrial revolution.
Facts about climate change
- The Earth’s surface has warmed by about 0.75°C on average since around 1900 and by around 0.4°C since the 1970s.
- More than 30 billion tonnes of CO2 are emitted globally each year by burning fossil fuels.
- Average global temperatures may rise between 1.1°C and 6.4°C above 1990 levels by the end of this century.
Global warming
The Earth’s surface has warmed by more than 0.75°C since around 1900, with much of this warming occurring in the past 50 years.
The 2007 Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) concluded it is very likely (more than 90% probability) that most of the observed global warming since the mid-20th century is due to the observed increase in human-caused greenhouse gas (GHG) concentrations.