Thanks to a huge jump in Chinese emissions, “global carbon-dioxide (CO2) emissions from fossil-fuel combustion reached a record high of 31.6 gigatonnes (Gt) in 2011. “The new data provides further evidence that the door to a 2°C trajectory is about to close,” according to IEA Chief Economist Fatih Birol. Why does that matter?

Scientists say ensuring global average temperatures this century do not rise more than 2 degrees Celsius above pre-industrial levels is needed to limit devastating climate effects like crop failure and melting glaciers.

Birol said “This trend is perfectly in line with a temperature increase of 6 degrees Celsius [11°F], which would have devastating consequences for the planet.Even School Children Know This Will Have Catastrophic Implications for All of Us.” If only school children ran the country.

In fact, the scientific literature now makes clear that even 4°C (7°F) warming would destroy the livable climate 7 billion people have come to depend upon.So what is the ‘good’ news?

We have been reducing our emissions:
CO2 emissions in the United States in 2011 fell by 92 Mt, or 1.7%, primarily due to ongoing switching from coal to natural gas in power generation and an exceptionally mild winter, which reduced the demand for space heating. US emissions have now fallen by 430 Mt (7.7%) since 2006, the largest reduction of all countries or regions. This development has arisen from lower oil use in the transport sector (linked to efficiency improvements, higher oil prices and the economic downturn which has cut vehicle miles travelled) and a substantial shift from coal to gas in the power sector.

Actually, the change in vehicle miles traveled (VMT) predated the downturn. VMT “began to plateau as far back as 2004 and dropped in 2007 for the first time since 1980,” as Brookings has reported. Indeed, per capita driving saw “flat-lining growth after 2000 and falling rates since 2005.”

The point is that given Obama’s strong new fuel economy standards and the reality of peak oil (that high oil prices are here to stay absent a global depression), the U.S. could meet its Copenhagen target of a 17% reduction in CO2 from 2005 levels with a pretty modest carbon tax (see “Bipartisan Support Grows for Carbon Price as Part of Debt Deal”). And that is the prerequisite for a global deal that would take us off the 6C path and give us a fighting chance at 2C.