There can never be “proof” of human-induced climate change – and we shouldn’t look to science to provide that. Science is about the estimation of likelihood based on available evidence. There will always be uncertainties because the earth-atmosphere system is too complicated to be understood in intimate detail. So judgement is required.
There are two possibilities: either climate change is human-induced or it isn’t. Despite some inconsistencies in the former possibility, the available evidence is overwhelmingly at odds with the latter. If faith can be described as belief held despite a dearth of supporting evidence, then the “sceptical” camp has a far greater need to cling to it.
The most reasonable judgement is that future climate will fall within the range of IPCC scenarios. Both the rosier and the “gloomier” projections are among the least likely of them. But the mid-range projections don’t make for happy reading either. It’s kind of like riding a bike with no brakes onto a busy road (bear with me). You might get across clean or you might get mown down by a freight truck, but most likely, you’ll get clobbered by a mid-sized sedan, say a Commodore. It still won’t be pretty.
The world’s climate has varied throughout geologic time, but there are no natural forcings that can adequately explain the current warming, which is broadly consistent with the radiative effects of more greenhouse gases in the atmosphere.
It would be ridiculous to suggest that scientists who dissent from this view have not been given an adequate airing in the media. In the past ten years their voices have been heard out of all proportion either to their representativeness of the climate community at large or the evidence they bring in support of their views.
Ironically, by refusing to take action on climate change, John Howard is effectively shifting the gloomier predictions up the probability curve. His balance is an artificial one – we can’t meet the climate halfway on this, can’t strike a compromise amenable to both parties. Even confining our arguments to the purely economic, there is every indication that climate change will be disastrous for Australia. In other words, the only thing that seems certain is that things cannot go on as they are.
Nobody wants global warming to be a reality and neither Gore nor Flannery is involved in “forecasting the apocalypse”. They may be making money popularising the subject, but the suggestion that money drives the research agenda only holds if there are a bunch of climate scientists who can no longer see their computer screens for the annoying wads of cash piling up on their desks.
On the other hand, the fossil fuel industry is looking more lucrative by the day. The top 15 US oil CEOs were paid, on average, $32.7 million last year, around 280% more than CEOs in comparably sized non-oil businesses.
But I’m sure that isn’t clouding anybody’s judgement.