So, I heard a new and depressing phrase today – “the gigaton gap”.  UNEP published a technical report, just before the Cancun COP, on the gap between likely emissions under any global agreement, and our best scientific understanding of what our emissions levels need to be to prevent warming beyond 2 degrees Celsius over the next 90 years.  The findings were stunning (but sadly not all that surprising)

• To get on a path likely to keep us at or below 2° C of warming, we would need to hold ourselves to emissions levels of  44 gigatonnes of carbon dioxide equivalent (this includes all CO2 emissions, as well as emissions of other greenhouse gases normalized to CO2 by converting their impact to the amount of CO2 required to create that same impact).

Yeah, it is a huge number, so big as to be meaningless – but don’t worry about the huge number – worry about how this number stacks up the next set of numbers

• If we just keep doing what we are doing, projections have us at 56 GtCO2e in 2020, leaving a gap of 12 GtCO2e.  That is a big, big gap.  Horrifically huge.  Hell, we have a gap equal to 21% total emissions!
• Low ambition pledges are not that much better.  Lenient implementation of such pledges would lower emissions to around 53 GtCO2e, leaving a gap of 9 GtCO2e.

But this really gets depressing when we look at the “good” scenario:

• Even under a best case scenario for the agreement, emissions would only drop to about 49 GtCO2e, STILL LEAVING A GAP of 5 GtCO2e.

“But 5 is much better than 12 or 9, right?” you say.  Well, it is better.  But 5 GtCO2e is approximately equal to the annual global emissions from all the world’s cars, buses and transport in 2005.  ALL OF THEM.  So 5 GtCO2e is not good news.
Summary: In Cancun, we kicked any real action down the road a year, making things harder to achieve under any circumstances.  We already knew this.  But, even under the good scenarios, we were going to come up short of what was needed – something many have long suspected, but after Copenhagen and Cancun, we now have numbers people are likely to commit to, so the analysis becomes a lot more read.  Ladies and gentlemen, ditch the global agreement – we can do this other ways.