Guardian Unlimited | Barrier reef bleaching worsens:

Coral bleaching caused by global warming could devastate swaths of Australia's Great Barrier Reef within 50 years, according to a report.

The study, commissioned by the Queensland government, found that bleaching could be an annual occurrence by 2050.

Coral bleaching happens when high water temperatures kill off the algae which live alongside coral polyps and give reefs their vibrant colours. At first the only serious damage is to the reef's appearance, but serious bleaching can destroy coral altogether.

Scientists classify the event as catastrophic if high temperatures occur for more than 100 days in a year. Such reefs do not regain their appearance for 10 years, and can take 50 years.

The main reason given for our failure to ratify Kyoto is the cost to the Australian economy. Even in terms of dollars and cents that is indefensible. if the Great Barrier Reef collapses that will have an effect on tourism. If the Murray-Darling basin falls victim to river failure or salination that will cripple our agrosector. The government should think again.