The unfortunate reality is that genuine action on climate change will require that existing coal-fired power stations cease to operate in the near future. We feel it is vital that you understand this and we are happy to work with you and with governments to begin planning for this transition immediately.
The letter is from David Karoly, a scientist at the University of Melbourne and a lead author of the IPCC Fourth Assessment. It was co-signed by five colleagues, two of whom were also IPCC co-authors.
In their letter, the authors argue that the world is poised on the threshold of a number of climate tipping points:
Evidence is mounting that climate change is occurring faster than previously predicted and we are perilously close to a number of tipping points which, if passed, would amplify the effects of climate change and make it much more difficult to bring further warming under control. We cannot emphasise enough just how serious the situation has become.
In a post at Crikey (an Australian online venue for independent journalism), Karoly explains why he and his colleagues have waded into the debate over climate policy:
As scientists, we have refrained in general from proposing policy, but when the direction we continue to take in this country is so clearly at odds with the scientific evidence, we have no choice but to speak out.
The consequences are too severe to do otherwise.