About climate change
Climate change occurs due to the worldwide gradual temperature increase and associated complex climatic changes resulting from higher concentrations of greenhouse gases in the earth’s atmosphere and the increased trapping of infrared radiation.
Greenhouse gases are a natural part of the atmosphere. They absorb and re-radiate the sun's warmth, maintaining the earth's surface temperature at a level necessary to support life.
The problem we now face is that human actions - particularly burning fossil fuels (coal, oil and natural gas), agriculture and land clearing - are increasing the concentrations of the gases which trap heat. This is known as the enhanced greenhouse effect, which is contributing to warming the earth’s surface.
Since the industrial revolution and expansion of agriculture around 200 years ago, humans have been raising the concentration of carbon dioxide gas in the global atmosphere. Human activity, particularly the burning of fossil fuels, has made the blanket of greenhouse gasesaround the earth thicker.
Levels of other greenhouse gases (methane and nitrous oxide) have also increased due to human activities.
The resulting increase in global temperatures is altering the complex web of systems which allow life to thrive on earth - such as cloud cover, rainfall, wind patterns, ocean currents, and the distribution of plant and animal species.
For answers to frequently asked questions about climate change, click here.