New purple alert signals need for climate talks

The colour purple is the new climate alert. It is the shade Australian weather forecasters added to their maps in anticipation of record high temperatures - over 50 degrees Celsius in some parts of the continent. It is not as if Australia is unused to searing heat. But meteorologists say the heat this season is unprecedented for duration, intensity and extent.

Climate-change sceptics will dismiss this as an extreme weather event rather than a sign of global warming. To be sure, a single event is no indicator. But this one follows on the heels of a pattern of extreme events last year - heat waves and freezes, flood and drought - around the world. And a US government agency says last year was America's warmest on record going back to 1895 and the second-worst for weather extremes including drought, hurricanes and wildfires. Scientists have told us to expect more of the same, especially heat waves and floods.

This will prompt some sceptics to think again, but more importantly, it should add urgency to UN talks on globally co-ordinated action on climate change. Since the failure of a summit of world leaders in Copenhagen three years ago, progress has been glacial compared with the loss of Arctic ice cover during last summer alone.

The stage is set for real progress after the latest talks in Doha last month extended the Kyoto protocol until 2020. Kyoto, the sole legally binding plan to halt the growth of global emissions, applies only to rich developed nations. It sends the right signal to poor developing nations, but is relatively ineffective without the participation of the US, China and India. Extending it clears the way for serious negotiations on a new treaty, to take effect from 2020, under which all countries, rich and poor, would tackle global warming. Given the lack of consensus so far, there is no time to lose if a deadline of 2015 for sealing a new agreement is to be met. That would leave a five-year window until 2020 for China, India and other developing economies to prepare for carbon emissions curbs that are seen as fair, rather than an obstacle to growth and higher living standards.