Weather data for 1999 being published this week will probably cause less fuss than much of the economic data that is published through the year.
The latest data show that the 1990s was the warmest decade since 1910 when reliable records were made. Moreover, it is a steady increase since the 1960s, not a one-off event. The national annual mean temperature during the 1990s averaged 0.33°C higher than the average for the rolling 30-year reference period of 1961 to 1990. Compared to the beginning of the century, national annual average temperatures at the end are about 0.8°C higher. Five years during the 1990s were among Australia’s top 10 warmest years with 1998 being the warmest on record. Last year’s average maximum temperature was equal to the long-term average but the minimum was higher than average, as forecast.
The Australian experience is similar to that in the rest of the world. The 1990s was the hottest decade since instrument records began in the 1860s. And last year was the fifth warmest on record.
Increasingly, the evidence is showing that the world is warming. The question is whether the warming is being caused by increases in greenhouse gases, such as methane and carbon dioxide. The increase in greenhouse gases have come with industrialisation. These gases trap heat in the earth’s atmosphere.
It may be, however, that the warming is a short-term phenomenon. It may be being caused by other things outside human control. On the other hand, the warming might be preventing the onset of a natural ice age, so we are doing ourselves a favour. There are several hypotheses which can be dreamed up to allow us to continue to put our heads in the sand. None of them have the same observable evidence as the greenhouse effect and the resultant global warming.
Humankind now has to face the fact that the earth is warming and that the most probable cause is industrialisation’s emission of greenhouse gases. It can be ignored. And we may get away with it. But because the potential damage is so high it would be prudent to take steps to reduce greenhouse gases, particularly as there would other beneficial environmental effects.
Some efforts have been made to reduce greenhouse gases with the 1997 Kyoto accords. But they may not be enough, especially in Australia’s case. Under the agreement, Australia has to limit the growth of its greenhouse emissions to 8 per cent over 1990 levels by 2008 to 2012. (Even by 1997 they were 11 per cent over the 1990 level, excluding landclearing.) Australia argued that as land-clearing was declining it should have a more lenient target, but that position has been under-mined by panic clearing in Queensland as farmers sought to beat tough controls belatedly introduced by the State Government last year.
The warmer climate patterns make Australia’s position look even more selfish. Australia and the rest of the world should get more serious about greenhouse emissions than the Kyoto targets. It would be better to take reasonable preventative measures than have sudden, disruptive measures forced upon us. Or worse, have a climatic catastrophe that cannot be reversed. We cannot say we were not warned.