Photo by Kyrylo Kalugin.

The "emissions gap" is the difference between "business-as-usual" greenhouse gas emissions, which continue to rise, and the level such emissions actually need to fall to in order to keep average global warming below 2 degrees C (3.6 degrees F) -- the goal that was internationally agreed to at the Cancun climate talks in 2010.

To keep warming below that level, we'd have to have achieved a cut of 12 billion tonnes of greenhouse gas emissions by 2020. That's the gap we must bridge.

In spite of the tremendous effort by the United Nations Framework Convention on Climate Change Secretariat, negotiations to start reducing global greenhouse gas emissions are going through a difficult stretch. The negotiations have increasingly turned into “I will only accept limitations on my economy if I’m absolutely sure you will do the same for yours," obscuring the fact that many emissions reduction measures have multiple benefits. Attention is shifting to a treaty that takes effect from 2020, and the country commitments for the period 2012-2020 would close half of the gap, at the very best.

So how do we bridge this gap? There are plenty of realistic steps we can take. At least a third of them involve energy efficiency. And many of these measures have environmental and economical benefits, beyond their reduction of greenhouse gas emissions. Front-running companies, cities, and individual citizens are taking climate action on their own, demonstrating that the potential and the benefits are real.

As it has become apparent in recent years that top-down approaches alone would not work, many have urged a bottom-up plan. But so far, no concrete proposals for this on a global scale have been put forward.

Our "Wedging the Gap" paper proposes such a bottom-up approach, building on all the rapid developments in technology and implementation and on the great initiatives in many places to bridge the global emissions gap.

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