National post-2020 greenhouse gas targets and diversity-aware leadership

Achieving the collective goal of limiting warming to below 2 °C or 1.5 °C compared to pre-industrial levels requires a transition towards a fully decarbonized world. Annual greenhouse gas emissions on such a path in 2025 or 2030 can be allocated to individual countries using a variety of allocation schemes. We reanalyse the IPCC literature allocation database and provide country-level details for three approaches. At this stage, however, it seems utopian to assume that the international community will agree on a single allocation scheme.

Here, we investigate an approach that involves a major-economy country taking the lead. In a bottom-up manner, other countries then determine what they consider a fair comparable target, for example, either a ‘per-capita convergence’ or ‘equal cumulative per-capita’ approach. For example, we find that a 2030 target of 67% below 1990 for the EU28, a 2025 target of 54% below 2005 for the USA or a 2030 target of 32% below 2010 for China could secure a likely chance of meeting the 2 °C target in our illustrative default case. Comparing those targets to post-2020 mitigation targets reveals a large gap. No major emitter can at present claim to show the necessary leadership in the concerted effort of avoiding warming of 2 °C in a diverse global context.

Authors

Malte Meinshausen, Louise Jeffery, Johannes Guetschow, Yann Robiou du Pont, Joeri Rogelj, Michiel Schaeffer, Niklas Höhne, Michel den Elzen, Sebastian Oberthür, Nicolai Meinshausen

Specifications

Publication title
National post-2020 greenhouse gas targets and diversity-aware leadership
Publication date
26 October 2015
Publication type
Publication
Magazine
Nature Climate Change
Product number
2038