Impacts of climate change

Globally, temperature increases have already led to observed melting of sea ice, permafrost and mountain glaciers.  Almost all the glaciers in the world are now receding, many of them quite rapidly.

In 2002, a section of the Antarctic Larsen Ice Shelf, the size of Kakadu National Park, collapsed due to thinning of the shelf as a result of extensive warming in that area.  The west coast of the Antarctic Peninsula is the most rapidly warming part of the planet with an average temperature rise of nearly 30C.

Satellite date since 1978 shows that the Arctic sea ice extent has shrunk substantially.  In the summer of 2005, the area of ice was 20% below the average minimum from 1978 to 2000.

These events, as well as seawater expansion due to higher temperatures, have caused a measurable rise in sea levels.  Over the last century, the average global sea level rose by 17cm, with the rate increasing in the last 10 years.

Extreme weather events, such as heatwaves, drought, hurricanes, storms and flooding, are increasing.  Eleven of the twelve years to 2006 rank in the twelve hottest years on record (since 1860).

The Intergovernmental Panel on Climate Change’s (IPCC’s) best estimate from its Fourth Assessment Report 2007 is that the average global temperature will rise by 1.80C by the end of this century in a low emission scenario and by 4.00C in a high emission scenario.  Allowing for uncertainties, the rise could be as high as 6.40C.

Temperature rises of this order will have wide-ranging and significant impacts on the world’s ecosystems, water resources, food supply, public health, infrastructure, forestry and economy.  A summary of possible impacts under a range of temperature rises can be viewed here

back to top

Impacts in Australia  

In Australia, the average temperature has increased by 0.90C since 1950.  This change has already had a measurable impact with significant decreases in regional rainfall and unprecedented rates of coral bleaching at the Great Barrier Reef.

Projections are for temperatures to continue to rise, by 1 to 50C by 20701; rainfall to decrease in the south by up to 30% under a high emission scenario, while extreme weather events, such as storms and floods, increase elsewhere; tropical cyclones to become more severe; heatwaves to become more frequent; and for sea levels to continue to rise.

These changes are expected to have significant impacts on Australia’s environment, economy and communities.  Australia is particularly vulnerable to these impacts with its fragile ecosystems, coastal communities and existing water supply concerns/constraints. 

Australia has over 580 flora species and over 145 fauna species listed as endangered or critically endangered.  Small variations in climate could have serious impacts on these species.  Particularly vulnerable ecosystems include the wet tropics, Kakadu, alpine areas, coral reefs, freshwater wetlands and heathlands in south-western Australia.

Further information:
• Climate Change in Australia Technical Report 2007.
• CSIRO report, ‘Climate Change Impacts on Australia and the Benefits of Early Action to Reduce Global Greenhouse Gas Emissions’ 2007.