Sometimes you wonder if anyone actually heeds the warnings any more. There have been so many of impending doom about climate catastrophe, that people seem oblivious to the warnings.

Two scientific reports released today maybe the ones where people sit up and notice.  One of the lead scientists thinks so. “This changes the way we think about climate change,” said Myles Allen, of Oxford University, a lead author of one of the studies.

Myles’ research has shown that the world has already burned half the fossil fuels necessary to bring about a 2C rise in average global emperature.

About a trillion tonnes of carbon have been consumed since the industrial revolution: humans must not emit more than 1 trillion tonnes of carbon into the atmosphere if we are to have a 50:50 chance of limiting global warming to 2 °C. On current rates. That figure will be reached in 40 years, maybe even in 20 years.

Putting this in real terms is that to avoid “dangerous” climate change, we must not burn more than one-quarter of our remaining reserves of fossil fuels.

This adds a new angle to the debate on peak oil, and declining reserves. We know that conventional oil reserves are becoming harder to find, the oil industry is turning to dirtier and more climate intensive unconventional oil, but this cannot be allowed to happen, as the climate costs will be catastrophic.

As Fiona Harvey points out in today’s Financial Times: “It would mean, for instance, that Canada would have to leave its oil tar sands untapped, and Saudi Arabia would need to leave most of its oil reserves in the ground to avert disaster.”

According to Allen “To avoid dangerous climate change we will have to limit the total amount of carbon we inject into the atmosphere, not just the emission rate in any given year.”

So limiting the carbon, means leaving the oil in the ground. That’s a game-changer for the oil industry. Its about time that the investment community understood what this actually means. Oil is no longer a safe buy. Its a sell.