Repères 14/05/08 - Concentration de CO2 dans l'atmosphère - Pire que prévu

Le niveau de concentration de CO2 dans l'atmosphère est plus important que prévu et fait craindre que le changement climatique soit d'ores et déjà hors de contrôle, avant même que nous ayons fait quoi que ce soit pour le limiter.

 

World CO2 levels at record high, scientists warn
Guardian May 12 2008

"The concentration of carbon dioxide in the atmosphere has reached a record high, according to new figures that renew fears that climate change could begin to slide out of control.

Scientists at the Mauna Loa observatory in Hawaii say that CO2 levels in the atmosphere now stand at 387 parts per million (ppm), up almost 40% since the industrial revolution and the highest for at least the last 650,000 years...

...Scientists say the shift could indicate that the Earth is losing its natural ability to soak up billions of tons of carbon each year. Climate models assume that about half our future emissions will be re-absorbed by forests and oceans, but the new figures confirm this may be too optimistic. If more of our carbon pollution stays in the atmosphere, it means emissions will have to be cut by more than currently projected to prevent dangerous levels of global warming.

Martin Parry, co-chair of the Intergovernmental Panel on Climate Change's working group on impacts, said: "Despite all the talk, the situation is getting worse. Levels of greenhouse gases continue to rise in the atmosphere and the rate of that rise is accelerating. We are already seeing the impacts of climate change and the scale of those impacts will also accelerate, until we decide to do something about it."

 

Ice cores reveal climate secrets
Nature 14 May 2008

"The amount of greenhouse gas in the atmosphere is higher than an any other point in the past 800,000 years.

Greenhouse-gas concentrations are higher today than they have been at any point in hundreds of millennia, according to researchers who have analysed tiny air bubbles trapped in Antarctic ice that dates back 800,000 years..."