Bridging the greenhouse-gas emissions gap

Twenty-one coherent major initiatives could together stimulate sufficient reductions by 2020 to bridge the global greenhouse-gas emissions gap.

We propose a new approach — which we call 'wedging the gap' — consisting of 21 coherent major initiatives that together would trigger greenhouse-gas emission reductions of around 10 gigatonnes of carbon dioxide equivalent (Gt CO2e) by 2020, plus the benefits of enhanced reductions in air-pollutant emissions.

This supports and goes substantially beyond the emission reductions proposed by national governments under the United Nations Framework Convention on Climate Change (UNFCCC). The approach would play a significant part in bridging the gap between current emission trends and what is necessary to put the world on a path that would limit global temperature increase to 2 °C above pre-industrial levels. The proposed initiatives build on actions that promise numerous benefits to the organizations and individuals undertaking them, and front-runners are already demonstrating that such benefits are real.

These initiatives aim to take these benefits to the mainstream, drastically amplifying their impacts and showing all organizations involved that together they can play a leading role in solving the climate challenge. Many of the initiatives also generate significant 'green growth' benefits, stimulating economic development based on environmentally sound solutions and providing additional motivation to engage. We expect that working together on a grand coalition would serve as a catalyst for action, greatly enhancing the willingness of a range of sub-sovereign and non-state actors to contribute to greenhouse-gas emission reductions. This in turn would support the implementation and strengthening of the pledges for which national governments remain responsible, and eventually stimulate sufficient reductions to bridge the greenhouse-gas emissions gap.

The efforts to reduce greenhouse-gas emissions by 2020 proposed by national governments under the UNFCCC alone are at present insufficient to limit global average temperature increase to 2 °C above pre-industrial levels — a limit agreed by the international community in Copenhagen in 2009 and in Cancún in 2010. A report published by United Nations Environment Programme (UNEP) in November 2011 called Bridging the Emissions Gap synthesized major scientific studies on this subject1, 2. The report shows that for the year 2020 there is an emissions gap of approximately 12 Gt CO2e between business-as-usual development and pathways compatible with a maximum temperature rise of 2 °C.

After the UN climate conference in Copenhagen in 2009, all major governments provided pledges on emissions reduction and limitation (see, for example, ref. 3). The UNEP synthesis concluded that altogether these pledges from national governments will lead to at most an emission reduction of 6 Gt CO2e. Many of the pledges are conditional on each other or on financial support. The exact rules of their implementation are also largely unclear. Hence, the currently confirmed value of all the pledges together is even smaller — less than 3 Gt CO2e.

The international climate negotiations in Durban in December 2011 showed that there has been progress in several areas, but not on the ambition level of emission reductions by 2020. An important achievement was the agreement on the Durban Platform for Enhanced Action. A new ad hoc working group4 will work to agree by 2015 at the latest on “a protocol, another legal instrument or an agreed outcome with legal force to come into effect and be implemented from 2020”. Given the dynamics of the international climate negotiations in the past ten years, it is our assessment that it is unlikely that countries will raise their ambition for the period before 2020 without any positive external input. The Durban decisions alone essentially postpone a discussion on ambition. This means that at the most only half of the 12 Gt gap is covered by the action of national governments under the UNFCCC, although a greater emission-reduction potential is available. Sector-by-sector analysis1 shows that the emission-reduction potential is 17±3 Gt CO2e by 2020.

So, in principle, it is possible to bridge the emissions gap. The question is whether there are other ways to realize this potential, in addition to the pledges and actions from national governments under the UNFCCC. We therefore suggest an approach driven by 21 additional initiatives to reduce greenhouse-gas emissions before 2020: wedging the gap (using the term 'wedges' coined by Pacala and Socolow5 in this context).

To read the full paper with the 21 initiatives, click here.