Tuesday 15 July 2008

climate change continues to bite in australia

The latest information continues to confirm the predictions of climate change models.

2005 was the hottest year on record across Australia, and the five year period 2003-2007 was also the hottest on record (Annual Australian Climate Statement 2007). The worst affected areas are in the southeast where both population and agriculture are greatest.

Graph by Aust Bureau of Meteorology

Much of eastern Australia remains in drought. Recent rainfalls have been slightly above average, but over the last 5 years rainfall has been low. But the biggest problem, as predicted by climate change models, is that the patterns of rain are changing.

  • Some relatively unpopulated parts of northwestern Australia are receiving above average rain.
  • However the southeast, including the Murray Darling River basin which produces 40% of Australia's agricultural production and 70% of its irrigated agriculture, has experienced its lowest rainfall on record overall (ABARE Outlook 2008).
  • Streamflows in the Murray Darling remain very low, with the current drought the worst on record. 2006 had the lowest inflows on record, and while 2007/08 was "only" the sixth lowest, June 2008 was the lowest monthly flow on record (ABC News, Adelaide Now, MDBC).
  • The river supplied the lowest volume of water ever to irrigated agriculture in the 2007/08 year (ABARE Outlook 2008).

It seems that climate change scepticism is increasing along with the temperatures, mostly based, as far as I can see, on isolated statistics, for example, that the hottest year on record was a decade ago in 1998, and it has been cooler since. The above facts seem to present difficulties to this scepticism, at least for us here in Australia. The worldwide data has been examined by Australia's premier scientific body, the CSIRO, which has concluded:

"1998 was the warmest year on record in the last 150 years. Although the eight years since then have not been warmer than 1998, they do include the globe’s second, third, fourth, fifth, sixth and seventh warmest years on record. The planet is not cooling."

Graph by CSIRO.

But in the end, we should base our conclusions on the full worldwide data set and the best expert opinion, which is summed up in the climate models and their predictions. I outlined this evidence in maybe, just maybe, we're starting to get this right.

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