Climate Commission

Is the world still warming?

Question from Grant Conn - Victoria

Records of global temperatures for the last century show that Earth’s surface has warmed by about 0.74°C, and that the warming trend is continuing. Warming of the Earth can also be seen through increasing ocean temperatures and melting of snow and ice.

Those who claim the globe is cooling often base their analysis on short time periods. Natural variability in the climate makes it inappropriate to use short time periods to draw conclusions on long term trends. For example, just because 2011 was cooler than 2010, some people have mistakenly used this to assert that the globe is no longer warming and may be cooling.

One or two cooler years does not provide evidence that warming of the Earth has stopped. Scientists studying the climate are careful to look at trends over 30 years – and preferably much longer – because shorter-term changes can be misleading due to natural variability.

Despite 2011 being a La Niña year (which La Niña years are generally cooler with higher than average rainfall and cloud cover), preliminarily global data indicates that 2011 is likely to be the equal tenth warmest year on record and the warmest La Niña year on record.

Find out more:

• The article Waiting for Global Cooling, written by Robert Fawcett and David Jones of Australia’s Bureau of Meteorology, debunks the claim that the globe has been cooling since 1998, and clearly explains why a ‘trend’ can’t be drawn from one or two years of warmer or cooler temperatures.
•  The Bureau of Meteorology’s Annual Australian Climate Statement 2011 provides up-to-date information on the long-term trends in Australia’s climate. Temperatures in Australia have risen around 0.8°C over the past century.