Townsville Bulletin: Global warming or ordinary weather? [ 03jun06 ]

GLOBAL warming is one of those issues which brook no debate.The prevailing, in fact overbearing, thought seems to be that any questioning of the basic premise, that the world is just about to come to boiling point if we don't all change our ways, is akin to blasphemy and makes the questioner not just an idiot, but irresponsible and uncaring.
Islands will sink beneath the waves, all the coral reefs will die, the polar ice caps will melt and we'll all be rooned.
The proponents of this viewpoint may well be right. I ride a bike and try not to use plastic bags and all those other responsible things just in case.
But it is interesting to see that not all scientists are in agreement with this gloomy theory and some argue just as vehemently that the global warming we are seeing is nothing to do with us and is well within the parameters of what we should expect.
PROFESSOR Bob Carter of James Cook University's Marine Geophysical Laboratory said in an address in Townsville in 2004 that during some climate changes, temperatures can swing by several degrees over periods as short as a few years, to a few decades. "Much discussion about global warming and climate change is based almost exclusively on the climatic record of the past 1000 years," he said.
"This is an inadequate period over which to assess the magnitude and rate of natural climate change, especially in judging whether contemporary climate change is unusual.
"Geological studies show the climate is always changing. It also reveals that climate change often occurs cyclically, with periods of change ranging between 11 years, through to 20,000, 41,000 or even millions of years."
PROFESSOR Carter also points out that greenhouse gases and land-use changes are not a recent phenomenon.
"An influence on climate through enhanced greenhouse gases and land-use changes has been hypothesised to date back to the development of agriculture in the Neolithic age, about 8000 years ago," he said.
"The cause of many rapid climate changes remains unknown but it's unlikely that greenhouse gas fluctuations are responsible for them.
"Greenhouse gases are a benefice, which we can thank for raising Earth's average temperature from a chilly minus 18 degrees Celsius, to the estimated modern value of about 15 degrees. Carbon dioxide plays a role, though a minor one, in that effect."
And he's not alone in his beliefs. William Kininmonth, meteorologist and head of the National Climate Centre for 12 years until 1998 agrees.
b>"THE science linking human activities to climate change is simplistic ... We are in a relatively warm part of the Ice Age cycle that has lasted more than 8000 years, but temperatures have been higher during this period," he said. "The evidence that the climate system may pass some imagined critical point that leads to runaway global warming is not convincing. Our future is one where we will have to adapt to a naturally changing climate. It is a delusion that dangerous climate events are new and will be averted by reducing carbon dioxide emissions."
THEN there's the scare campaign about polar bear numbers - global warming devotees are determined that numbers are falling because the ice fields are decreasing. Other equally qualified commentators dispute this, saying that not only are the icefields increasing, both at the north and south poles, but polar bear communities are mostly either stable or growing, so who to believe? Do we have polar bears or don't we?
SO it's far from a laydown misere that the world is about to boil us off its surface. It seems clear that the world is getting warmer, the dispute is whether this is because of humankind's efforts to wreck the atmosphere, or because of a natural cycle of warming and cooling. A British House of Lords committee concluded last year after grilling dozens of the world's top climate scientists: 'The science of climate change remains debatable.'
The answer is, then, that we don't know the answer. If global warming is not due to human pollution, then it will probably just keep to its own private pattern - this could well mean the polar ice caps will melt, Magnetic Island will be covered by the sea and we'll all be rooned. Or it could mean a new Ice Age will happen and we'll all be frozen off the face of the earth. The natural cycle is no respecter of our houses, or our persons. Either way, I don't suppose my bike is going to make much difference.