Archive for May, 2011

Another Letter on Climate Change

May 23, 2011

CLIMATE CHANGE AGAIN.

It rained last night, what a fantastic start to the 2011 season. Long may it continue. The Climate Commission released its first report today, written by Prof. Will Steffan, a world renowned climate scientist. Already I have heard angry calls to the radio exclaiming that “no one can predict the future!” No they can’t, but they can make a pretty accurate guess. The report does make the following conclusions with certainty because they are based on actual measurements: I quote-

 ––“The average air temperature at the Earth’s surface continues on an upward trajectory at a rate of 0.17 °C per decade over the past three decades.

––The temperature of the upper 700 m of the ocean continues to increase, with most of the excess heat generated by the growing energy imbalance at the Earth’s surface stored in this compartment of the system.

––The alkalinity of the ocean is decreasing steadily as a result of acidification by anthropogenic CO2 emissions.

––Recent observations confirm net loss of ice from the Greenland and West Antarctic ice sheets; the extent of Arctic sea ice cover continues on a long-term downward trend. Most land-based glaciers and ice caps are in retreat.

––Sea-level has risen at a higher rate over the past two decades, consistent with ocean warming and an increasing contribution from the large polar ice sheets.

––The biosphere is responding in a consistent way to a warming Earth, with observed changes in gene pools, species ranges, timing of biological patterns and ecosystem dynamics.”

The report also states the following:-

 –– “There is no credible evidence that changes in incoming solar radiation can be the cause of the current warming trend.

–– Neither multi-decadal or century-scale patterns of natural variability, such as the Medieval Warm Period, nor shorter term patterns of variability, such asENSO(El Niño-Southern Oscillation) or the North Atlantic Oscillation, can explain the globally coherent warming trend observed since the middle of the 20th century.

–– There is a very large body of internally consistent observations, experiments, analyses, and physical theory that points to the increasing atmospheric concentration of greenhouse gases, with carbon dioxide (CO2) the most important, as the ultimate cause for the observed warming.”

 I couldn’t have put it better myself. Chapter 2 of the report discusses the risks associated with a changing climate. The report looks at five risks (i) sea-level rise; (ii) ocean acidification; (iii) the water cycle; (iv) extreme events; and (v) abrupt, non-linear and irreversible changes in the climate system.

 The report emphasises the limitations of any predictions but it does say this in bold letters:-

“Apart from these insights, what we can say with certainty is that rainfall patterns will change as a result of climate change, and often in unpredictable ways, creating large risks for water availability.”

 This is an important debate. We are talking about the effect we are having on the lives of our children and grandchildren. They cannot afford for us to simply go red in the face and say we can’t change anything here. I commend this report to you, it is a very worthwhile read. Please post any comments on my blog- viewfromthefarm.wordpress.com.

 Regards.

Robert Lee

ps. Climate Commission web site is http://www.climatecommission.gov.au/