Further action is needed that goes far beyond what has been agreed so far under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol to “prevent dangerous anthropogenic interference with the climate system”, the ultimate objective of the UNFCCC. In stabilising and decreasing global emissions all countries shall act “on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities” (UNFCCC, Art. 3.1). This means that especially emerging economies and developing countries have the ability to develop. On this basis the Greenhouse Development Rights approach (GDRs) was developed by EcoEquity for global effort sharing (Baer et al. 2007).
This report compares the GDRs approach to several other effort sharing approaches, namely Common but Differentiated Convergence (CDC), Multistage, Triptych and Contraction and Convergence (C&C), for the different stabilisation levels of 450, 550 and 650 ppmv CO2eq. The calculations are done with the Evolution of Commitments Tool (EVOC), developed by Ecofys.
The implementation of the GDRs
in this report is very similar to what Baer et al. developed. The main differences are that the scope is a broader as all six Kyoto gases are included in this report and the Responsibility Capacity Index to calculate the GDRs reduction per country is calculated for every year between 2010 and 2050. Effort sharing under the GDRs approach depends very strongly on the BAU assumptions, the reduction paths and the resulting global emission reduction. Our calculations are based on the IPCC SRES scenarios.
Generally, only a reduction path aiming at a stabilisation at 450 ppmv CO2eq or lower will offer a good chance to stay below the 2° limit. However, we also show diagrams per country/group for higher stabilisation levels to understand impact of the choice of the stabilization level.
Countries or regions with a high RCI at the beginning, such as the USA or the EU 27, would have to take a big part of the global emissions reduction effort in early years. Because of this and because of the economic growth of other regions, such as China, India and other parts of Asia, their relative contribution would decrease a bit over time. For Annex I countries this could even lead to slightly increasing emission allowances after 2050, because many rapidly industrialising countries will have to
increase their contribution.
In this approach emission allowances can drop below zero, which means that even allowances have to be bough if emissions are reduced to zero. This would be the case for most Annex I countries in a few decades. Therefore, trading or any kind of infrastructure to transfer emission allowances will be necessary.
The effort under the GDRs is higher compared to other approaches for most Annex I countries since negative emission allowances are possible. However, this does not mean that the actual imposition for developed countries is higher compared to other approaches because also a high amount of financial support for more stringent non-Annex I targets would need to come from Annex I countries under other approaches as well.