This report shows national GHG emissions reductions for 2030 and 2050 that are consistent with the Paris Agreements’ long-term temperature goal, both based on fairness and cost-effectiveness approaches. The range of fair shares was derived from an evaluation of a broad spectrum of fairness-based approaches by the Climate Action Tracker. The cost-effective reduction shares are based on recent marginal abatement cost curves, which were used to derive globally cost-effective national pathways.

Main findings:

In the Paris Agreement, which came into force in November 2016, the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) agreed to limit global warming to "well below 2°C above pre-industrial levels" and to make efforts to "limit the temperature rise to 1.5°C above pre-industrial levels". Achieving this temperature goal will depend on sufficient national action by all countries, which will have to be strengthened and accelerated on an ongoing basis, as laid down in the review mechanisms of the PA. The current reduction commitments of the states, including those of Germany and the EU, are not sufficient to achieve the objectives of the Paris Agreement.

In the years prior to the 2009 United Nations Climate Change Conference in Copenhagen (COP15), the international community had an intensive discussion about suitable approaches for the regional allocation of greenhouse gas (GHG) reduction targets. Essential criteria that played a role in this discussion were the historical responsibility of the industrialised countries (in terms of cumulative GHG emissions caused), the mitigation capacity of the states (in terms of the level of development of the states, e. g. on HDI and GDP), the right to development (in terms of per capita emissions of GHG), technical and economic potentials for mitigation, as well as associated cost efficiency/welfare losses. However, the international community reached neither a consensus nor a compromise how to distribute the mitigation efforts.

The Paris Agreement, which stresses that contributions from the states have to reflect “the highest possible ambition” and “respective capabilities”, has shifted the focus to emissions pathways that limit global warming to well below 2°C, and undertaking effort to not exceed 1.5°C. In the following, global emissions pathways that are consistent with the 2°C temperature goal of the Cancun Agreements are referred to as 2°C-consistent pathways. Pathways that are consistent with the Paris Agreements’ long-term temperature goal will be called 1.5°C-consistent pathways.

The study underlying this policy brief has derived national GHG emissions reductions for 2030 and 2050 that are consistent with the Paris Agreements’ long-term temperature goal, both based on fairness and cost-effectiveness approaches. The range of fair shares was derived from an evaluation of a broad spectrum of fairness-based approaches by the Climate Action Tracker. The cost-effective reduction shares are based on recent marginal abatement cost curves, which were used to derive globally cost-effective national pathways.

A comparison of those approaches yields insights whether or not a country can or should increase the ambition of its NDC, for example because the NDC is much less ambitious as the mitigation potentials or the fair share of the country. The data can also show how large the efforts in the country domestically should be and indicate need for support to or from other countries, if there is a mismatch between the potentials for emissions reduction at a low cost and the fair share. The analysis focuses on countries that are particularly relevant because of their share in global GHG emissions and their role in international climate policy, namely Brazil, Canada, China, the EU, India, Japan and the United States of America. In addition, particular emphasis is given to the role of Germany.