The Australian – WIDELY-HELD assumptions that climate change is responsible for an upsurge in extreme drought, flood and storm events are not supported by a landmark review of the science. And a clear climate change signal would not be evident for decades because of natural weather variability.Despite the uncertainties, politicians – including US President Barack Obama in his address to federal parliament yesterday – continue to link major weather events directly to climate change.Greens leader Bob Brown yesterday highlighted Mr Obama’s climate change comments and said the extreme weather impacts were “not just coming, they are happening”. But rather than bolster claims of a climate change link, the scientific review prepared by the world’s leading climate scientists for the UN’s Intergovernmental Panel on Climate Change highlights the level of uncertainty. After a week of debate, the IPCC will tonight release a summary of the report in Kampala, Uganda, as a prelude to the year’s biggest climate change conference, being held in Durban, South Africa. The full report will not be released for several months but a leaked copy of the draft summary, details of which have been published by the BBC and a French news agency, have provided a good indication of what it found. While the human and financial toll of extreme weather events has certainly risen, the cause has been mostly due to increased human settlement rather than worse weather. Read Article
There is only “low confidence” that tropical cyclones have become more frequent, “limited to medium evidence available” to assess whether climatic factors have changed the frequency of floods, and “low confidence” on a global scale even on whether the frequency has risen or fallen.