Johann Hari: Don't kill the planet in the name of saving the economy

Continued...But time is exactly what we don't have. The key to understanding why lies in grasping the difference between a two-degree celcius rise in global temperatures and a three-degree rise. At first glance, neither sounds like a big deal. If you go out for a picnic and the temperature rises by three degrees, you take off your jacket. But if your body heats up one or two degrees, you get sick and take to your bed. If it heats by three degrees and doesn't go back, you die. The ecosystem isn't a picnic; it's more like your body. Small variations in global temperatures have vast consequences. The last Ice Age was only six degrees colder than today. A global rise of just 0.8 degrees has melted the Arctic.

Soon, we will have belched so many warming gases into the atmosphere that a two-degree rise will be locked-in and certain. That condemns Bangladesh and the islands of the South Pacific to drowning. But if we choose, we can stop there, and stabilise the climate at this higher temperature.

But if we go beyond two degrees, the climate begins to unravel, and the brakes won't work. At three degrees, almost all the world's ice is gone, and so it stops reflecting a third of the Sun's ray back into space – making the world hotter. At three degrees, the Amazon rainforest burns down, releasing all its stored carbon – making the world hotter. At three degrees, the Siberian peat-bogs melt and release vast quantities of methane into the atmosphere – making the world hotter. So three degrees turns inexorably to four and five and six. Screw the grandchildren and the polar bears: we're on course to heat by three degrees in my lifetime. I wish the deniers were right: I'd be on the first plane to Honolulu. But we can't live for long in an euphoric dream. Two degrees is the point of no return, and we're about to hit it.

The collision of these two crunches could be a boon. Just as the banking system imploded when it was left unregulated, the current carbon-spewing economy is on course to ecologically implode. The path out of both crunches is the same: concerted state action and re-regulation. To get out of the credit crunch, we need a big package of job creation and economic stimulus. To get out of the climate crunch, we need an army of millions of new workers – and billions in public spending – to insulate every home, construct millions of new renewable energy sources, and work on endless innovations that help us to decarbonise. See any overlap? Europe would get a head-start in green technologies – the great boom-market of the 21st century, if the world sees sense. Continued...

"There is no harm in going green I suppose. Even if it was previously claimed by Dr. Spencer that there is no global warming, I still opt for the reduction of CO2."