The Australian's judgement is wrong on two counts. First, climate is not determined by a single year’s average observed temperature. To suppose otherwise is just incorrect. Keith Colls and Richard Whitaker’s excellent, The Australian Weather Book, Second Edition, 2001 define climate as the probability distribution of the various elements of day-to-day weather. To determine this probability distribution, for weather patterns as variable as those for Australia, the authors suggest that it is necessary to draw on rainfall records dating back 150 years and temperature records drawing on 50 years (page 156). Second, there may well be medium term deviations from warming trends due to climatic effects related to cooling of the oceans. This is the reason I am strongly opposed to viewing the current drought as a reflection of climate change. If the public come to accept that medium term droughts reflect climate change they may falsely believe that medium term reductions in average temperatures imply that anthropogenic global warming arguments are false.
The difficulty with the foolish reasoning presented in The Australian is that it may cast sufficient doubt in the minds of the public and in politicians to forego activist climate change policy particularly given the current economic difficulties.
In fact the current cooling trend has been analysed at length by the Bureau of Meteorology. Their December 23, 2008 ENSO Wrap-Up states:
The equatorial Pacific has continued to cool during the past fortnight, with large areas in the east and centre of the basin between 0.5°C and 1.5°C cooler than normal. This raises the possibility of indicators reaching La Niña levels, even if only briefly, if the cooling persists. In the atmosphere, Trade Winds have been persistently stronger than normal for some months across the western half of the basin, cloudiness is suppressed along much of the central and eastern equatorial Pacific, and the SOI remains strongly positive, with an approximate 30-day value of +13 as of 21st of December.Thus there is the possibility of a cooling related to a La Niña event during the current summer.
Given current conditions and recent trends, the development of a La Niña during the southern summer cannot be ruled out. However, for the first quarter of 2009 the majority of climate models forecast neutral conditions, but with a cooler than normal equatorial Pacific. Historically, it is unusual for La Niña thresholds to be reached during the southern summer, though this did occur as recently as the summer of 1999/2000.
Further comments on The Australian’s arguments are provided at Deltoid.