{News} 080710 Qualifying climate change

Qualifying climate change

Fairfax Media, Jul 10, 2008

In the introduction to the CSIRO-BoM assessment of how future climate will drive future droughts is a run of qualifications that show all is not yet done and dusted in the world of climate change research.

Politically, carbon and its derivatives have been held up as a single visible target for addressing climate change.

But as the report preamble notes, many things influence our climate, not all of them well understood, or their interactions.

There is also a significant fudge factor in the authors' assessment of how global warming may be affecting our climate. Phrases like "very likely", "likely" and "partly" leave plenty of room for manouvre.

It would be unwise to ignore the overwhelming consensus by seasoned scientists that something is happening to our climate, and that carbon-based emissions are at the root of it.

Yet this is a planet made fit for life by extremely complex interactions. Each time that science discovers something, it finds more to learn.

A comment by Arctic explorer Dennis Schmitt rings true: "The problem is (climate change) has been streamlined with computer models that limit variable participation to generate predictions. This gives us some solid betting odds that we could well put our money on. But the complexities doom us to many probable reversals that may disappoint us if we come to depend on an 'ideology of global warming' for our psychological well being."

Climate change is occurring in Australia, whatever the cause(s), and as Mr Schmitt observes, we need something on which to lay betting odds. But because we're betting solely on carbon, it has expanded to fill our entire vision. Carbon drives the climate models being used to plan our future, it's capturing virtually all the investment being thrown at the problem, and it’s deciding our economic future.

There's a more complex world out there. While we're tackling our polluting ways, we should not, as Mr Schmitt advises, let carbon become the centrepiece of an ideology. Carbon may remain the hot favourite, but it's unlikely to be the only horse in the race. If we ignore the rest of the field by politicising carbon, we stand to lose our shirt, and a whole lot more.

* Examples from the CSIRO-BoM 'Drought Exceptional Circumstances' report to the Federal Ministry of Agriculture, Forestry and Fisheries:
"Australia has one of the most variable climates in the world. Internal and external factors drive climate variability on a range of timescales. Internal factors are natural and arise from complex interactions within the climate system, such as the El Niño–Southern Oscillation, the Indian Ocean Dipole, the Southern Annular Mode and the Inter-decadal Pacific Oscillation. Natural external factors include the Earth’s rotations, variations in the energy from the Sun, volcanic eruptions and changes in the Earth’s orbital parameters. Some external factors such as changes in concentrations of greenhouse gases, aerosols, stratospheric ozone in the atmosphere, and in land-use are human-induced."

"Most of the global and Australian warming since the mid-20th century is very likely due to increases in greenhouse gases. About 50 per cent of the rainfall decrease in south-western Australia since the 1950s is likely to be due to increases in greenhouse gases. The autumn rainfall decline in south-eastern Australia since the late 1960s may be partly due to increases in greenhouse gases."

Source: http://theland.farmonline.com.au/blogs/out-here/qualifying-climate-change/808530.aspx