The Federal Government’s adviser on climate change, Professor Ross Garnaut, has released his update on the science of climate change finding that observations and research outcomes since 2008 have confirmed and strengthened the position of scientists who maintain that the Earth is warming and that human emissions of greenhouse gases are the primary cause.

 

Professor Garnaut was commissioned by the Australian Government in November last year to provide an update to his 2008 Climate Change Review for the Australian community.

 

The recently released paper is the fourth in a series that will lead to a final report by the end of May.

 

In his overview of current climate science, Professor Garnaut concluded that:

  • global temperatures continue to rise around the midpoints of the range of the projections of the Intergovernmental Panel on Climate Change (IPCC) and the presence of a warming trend has been confirmed;
  • the rate of sea level rise has accelerated and is tracking above the range suggested by the IPCC; and
  • rates of change in most observable responses of the physical and biological environment to global warming lie at or above expectations from the mainstream science.

 

He found no reason to hope that the conclusions reached in the 2008 Review overestimated the risks of climate change. 

 

“The judgement of the Review that the greater risks of severe consequences under a scenario of 550 ppm concentrations of greenhouse gases make the extra mitigation cost to achieve a 450 ppm outcome worthwhile has been confirmed”, he concluded.

 

Further, Professor Garnaut found increasing discussion in scientific literature of the possibility that large damage will occur at smaller increases in global average temperature than the IPCC focus and United Nations (Copenhagen and Cancun) agreement on holding temperature increase to 2 degrees C or less above pre-industrial level. He argued that there is a case for seeking to reduce emissions concentrations below 450 ppm carbon dioxide equivalent, and to avoid high risks of dangerous climate change large changes in the trajectory of greenhouse emissions will be required at an early date.

 

The full text of the Update Paper 5: The science of climate change is available at http://www.garnautreview.org.au/