When James Hansen talks climate change, people listen. The head of climate studies at NASA, Hansen first gave evidence on the issue to the US Congress in 1988, and is now an eminent scientist and a prominent public advocate.

In new research just out, Hansen concludes that at the current temperature, no "cushion" is left to avoid dangerous climate change, and that the Australian government target goals  "... of limiting human-made warming to 2° and CO2 to 450 ppm are prescriptions for disaster".