Understanding climate change
Climate change science
Climate change is a change in the average pattern of weather over a long period of time.
There is clear evidence that our climate is changing, largely due to human activities. The Fourth Assessment Report, produced by the Intergovernmental Panel on Climate Change (IPCC) in 2007, states global warming is 'unequivocal' and 'most of the observed increase in globally-averaged temperatures since the mid-20th century is very likely due to the observed increase in greenhouse gas concentrations'.
In other words, there is overwhelming evidence for human-made global warming.
The IPCC report represents the international consensus on climate change science from literature that has been extensively peer-reviewed and published in scientific journals.
There are multiple lines of evidence that show the Earth's climate system is warming. These include increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.
When scientists talk about climate change they mean warming of the climate system as a whole, which includes the atmosphere, the oceans, and the cryosphere (ice, snow and frozen ground). The evidence clearly indicates that the climate system is continuing to warm, including increasing land temperatures, warming oceans and melting snow and ice.
Climate change is not just about global warming. The science indicates that the climate will be altered in many other ways. For example, there will be changes in rainfall patterns and ocean currents, changes to the intensity and frequency of extreme events such as storms, droughts and floods, rising global sea level and ocean acidification.
Further information
The Australian Academy of Science is the peak Australian science body made up of Australia's most distinguished scientists. The Academy has prepared a short report—The Science of Climate Change—which provides answers to key climate questions.
Similar organisations in other countries have also produced reports addressing climate change issues, for example the United States National Academy of Science and the Royal Society in the United Kingdom.
A Joint Science Academies' Statement—signed by the national scientific academies of Brazil, Canada, China, France, Germany, India, Italy, Japan, Mexico, Russia, South Africa, the United Kingdom and the United States—reaffirms the importance of taking action to reduce greenhouse gas emissions and begin the transition to a low-carbon global economy.
Australia's CSIRO runs a climate change website and provides 'comprehensive, rigorous science to help Australia understand, respond to and plan for a changing climate'. They've also released a book, Climate Change: Science and Solutions for Australia, drawing together the latest scientific knowledge on a series of climate change topics.
Australia's Bureau of Meteorology also runs a climate change website, aimed at providing decision-makers and the general public with access to accurate and reliable observations and information on the science of climate change.
The Climate Commission's report, The Critical Decade, brings together an up-to-date summary of climate science, the risks and responses.