A new global climate agreement by 2015 is crucial to keep global warming below the target of maximum 2 degree increase in this century. This will require enhanced ambitions for all Parties and transformational change towards sustainable, low-carbon development and green growth. In six articles, including one by PBL Netherlands Environmental Assessment Agency, crucial aspects of a possible new agreement are addressed.
In the book chapter on the global mitigation challenge, Niklas Höhne (Ecofys, Germany) and Michel den Elzen (PBL) describe the gap between the emission level expected for 2020 according to countries' pledges and the emission level that would be consistent with achieving the 2 °C target, assuming the emission reduction pledges in the Copenhagen Accord and Cancún Agreements will be met. This is based on the Emissions Gap Report 2012 of the United Nations Environment Programme (UNEP), updated with decisions taken in late 2012.
The emission gap estimated for 2020 will be 8 to 12 gigatonne (billion tonnes) CO2 equivalent, depending on how emission reduction pledges are implemented. The emission gap could be narrowed through implementing the more stringent, conditional pledges, minimising the use of ‘lenient’ credits from forests and surplus emission units, avoiding double-counting of offsets and implementing measures beyond current pledges. Closing the gap will become more difficult as more time passes.