Thursday, December 19, 2002. Posted: 21:12:55 (AEDT)

Drought-racked Australia sees hottest year ever

With Australia in the grip of a fierce drought, experts say the year 2002 will turn out to be its hottest ever in terms of maximum daytime temperatures.

National Climate Centre forecaster Blair Trewin says there does not appear to be much relief on the horizon from the hot and dry weather.

Mr Trewin says the El Nino weather phenomenon, which has brought cloudless skies over the parched outback and helped push peak daytime temperatures to record levels this year, has historically tended to be followed by an even hotter year.

"Daytime maximum temperatures this year averaged over Australia will almost certainly come in as the highest on record," Mr Trewin said.

"However, because what you tend to see in dry conditions is lots of clear days, which means big ranges between daytime and night-time temperatures, the average night-time minimum temperatures actually look like coming in very slightly below average."

The obvious culprit for the heat is global warming, which the United Nation's World Meteorological Organisation (WMO) says was reaffirmed by 2002 globally turning out to be the second warmest year recorded since 1860, surpassed only by 1998.

The WMO data was based on mean global temperatures, averaging out daytime highs and night-time dips, rather than the maximums.

Many scientists believe industrial pollution, in particular the emission of so-called greenhouse gases such as carbon dioxide, is responsible for trapping heat.

Mr Trewin says suspicion of this was due to the fact that most of the 0.5 degree Celsius increase in maximum Australian temperatures since 1910 had taken place since 1950.

It is still impossible to predict an end to the drought, which has chopped a percentage point off Australia's projected economic growth for fiscal 2003 and savaged the important agricultural sector.

But if history repeats itself and weather models are correct, average or above average rainfall could be expected to resume some time between January and March.

Mr Trewin added a word of caution for farmers desperate for rain.

"Because this year's drought has been so widespread, it's quite likely that even after you get a general break there will be some residual pockets of drought," he said.

"Where those will be is impossible to predict at this stage."