Gary, the claim that global warming is causing widespread coral bleaching right now is complete rubbish.

The global increase in temperature is an average of 0.5 degrees, that of the Coral Sea less than that. As the article itself said, bleaching occurs after a prolonged period of temperatures 2-5 degrees above the current average. Even then, despite being quite sensitive to short term temperature changes, coral reefs are millions of years old, and have survived highly variable temperatures throughout that period. Some science would even seem to indicate that an increase in temperature will be good for the reef -- at least over the long term, and it is over the long term that global warming is occuring.

What your map shows very well (and the Wikipedia article on reefs discusses) though, is that even in periods (such as the summer of 1998 shown) when sea temperatures are much higher, it is pollution along the coast that is the biggest danger to coral. If you are going to spend resources protecting reefs pollution is far and away more important -- not to mention, better value for money.

Russ,
I'm more open minded about the argument---tis more than a claim---than saying it is 'complete rubbish.' I've never been one for absolute certainity on complex issues such as global warming.

Your complete rubbish brings you close to an argument in the weekend AFR from Nigel Lawson, a former UK Chancellor of the Exchequer, entitled 'Beware the greens' age of unreason.' It is downloaded from the Nov.issue of Prospect

By 'greens' Lawson means the Intergovernmental Panel on Climate Change(IPCC). On his account natural science stands for the age of unreason(it is closed to reason and suppresses dissent)whilst economics stands for reason. The article ends with a rant about green absolutism, the quasi-religion of greenery replacing the vacuum of organized religion and any questioning of green mantra being seen as blasphemy, and green religion being harmful to economic growth.

However, I do agree with you that pollution from the sugar farms along the east coast are one helluva problem. And I would argue that little is being done to address this because it questions economic growth in terms of ecological market externalities.

Gary, my apologies if you read that against yourself. I was referring specifically to the article and the widespread myth regarding the current effects of global warming on coral reefs (and probably to a more general satistical illiteracy). It is probably worth adding as well: most of the problems of global warming involve an increased frequency of existing weather events. Local environmental issues tend to exacerbate the problem when it occurs (be it a drought, flood or a hurricane), so fixing local issues is probably the best defense against global warming anyway.

The IPCC is both fairly and unfairly characterised. The science within it is far more nuanced than either its supporters or detractors claim, but it tends not to get out. This is a journalistic error as much as anything; there is always someone, somewhere willing to say "such-and-such a weather event was caused by global warming", whereas you can never prove that.

Making future projections is perilous at the best of times so I doubt it will suprise anyone if they are wrong. I have seen a number of articles over the past few years that have said the economics is wrong and/or the carbon projections have been overstated within the report(s). That would indicate that temperature increases will be closer to the lower bounds -- but who knows?

Russ,
yeah I did read your comments as being directed against me.

I agree with your comments about journalism in general in Australia .I do think that you are a bit harsh on Fyfe's piece above.

On the surface it does look a bit dodgy-- eg., the 'undisputed scientifically' phrase. That may show a basic misunderstanding of how science works in terms of paradigms, hypothesis, and revision.

But to be fair to Fyfe she did say 'the problem with global warming and coral is quite clear and undisputed scientifically.' And she does talk in terms of the 'current prediction is that by the end of the century tropical ocean waters will be 1 to 3 degrees warmer.'

She also says that rising acid levels in the oceans and warming waters are equal threats to the reef and acknowledges the threats such as run-off from farms and outbreaks of pests such as the crown -of-thorns starfish; and she acknowledges the some coral has adapted to heat:
Some coral lives in 24- degree water off Lord Howe Island, while others can survive in 36-degree water in the Persian Gulf.