Friday, August 20, 2010

Australian Academy of Science outlines Climate Change Facts

On Monday the Australian Academy of Sciences released a report on Climate Change summarising in seven questions and detailed answers the scientific facts of climate change and Australia in straightforward language with the aim "to contribute to the public understanding of the state of the science and to attempt to tread a path through the often contradictory public commentary on the science."

The report - The Science of Climate Change - Questions and Answers - has been released in the final week of the Australian Federal election in which both the Labor Government and Opposition Parties are offering minimal policy action on climate. Both Government and Opposition parties have not responded to the report which has only received limited media coverage.

In the foreward to the publication Professor Kurt Lambeck, President of the Australian Academy of Science warns that decisions on how to respond to climate change need to be made by general society. "These decisions need to consider the findings of climate change together with many considerations that go beyond the science and must include, amongst others, ethics and equity, economics, risk management and politics."

The report's authors include many of Australia's foremost climate scientists, and was fully reviewed by a committee of Academy fellows.

While average temperatures are forecast to rise this century by 2 to 7 degrees Celsius, future impacts are expected to be severe if business as usual continues and no action is undertaken. The present business as usual approach with limited action will see average temperatures increase by about 4 degrees by century's end.

"If emissions continue unabated, current mid-range estimates are for 4.5°C higher global average temperatures by 2100 (see Question 5), which would mean that the world would be hotter than at any time in the last few million years. Sea level would continue to rise for many centuries. The impacts of such changes are difficult to predict, but are likely to be severe for human populations and for the natural world. The further climate is pushed beyond the envelope of relative stability that has characterised the last several millennia, the greater becomes the risk of passing tipping points that will result in profound changes in climate, vegetation, ocean circulation or ice sheet stability."

To mitigate the rise in average temperatures, reduction of greenhouse gas emissions could significantly reduce long-term warning the report says.

"To have a better than even chance of preventing the global average temperature from eventually rising more than 2°C above pre-industrial temperatures, the world would need to be emitting less than half the amount of CO2 by 2050 than it did in 2000. To do this on a smooth pathway, global emissions (which are still rising) would need to peak within the next 10 years and then decline rapidly."

The report does not outline what policy decisions should be taken for action on climate change:

"Decisions on when and how to respond to climate change involve many factors that lie outside the realm of science, including ethical and economic considerations. An appropriate response will depend on value judgements and an assessment of the risks of various courses of action. Just as in any other sphere of human activity, decisions will need to be made before we have absolute certainty about the future. The role of climate science is to inform these decisions by providing the best possible knowledge of climate outcomes and the consequences of alternative courses of action." concludes the report.

Last December 40 of the world's leading climate scientists said in an open letter released before the December 2009 Copenhagen Climate Conference that industrialised countries such as Australia need to aim for at least a 40 per cent carbon emissions reduction below 1990 levels by 2020, for a reasonable chance of avoiding dangerous climate change.

Signatories to this open letter from Australia included: Professor Ove Hoegh-Guldberg from the Centre for Marine Studies at the University of Queensland; Professor Lesley Hughes, an IPCC Lead Author from the Department of Biological Sciences at Macquarie University; Professor Anthony J McMichael, Professor of Population Health at the Australian National University, and Honorary Professor of Climate Change and Human Health, University of Copenhagen; and Dr Barrie Pittock, IPCC Lead Author and Honorary Fellow, CSIRO Australia.

The report - The Science of Climate Change - Questions and Answers - is available from the Australian Academy of Science - Science Policy page.

Takver is a citizen journalist from Melbourne who has been writing on Climate Change issues and protests including Rising Sea Level, Ocean acidification, Environmental and social Impacts since 2004.