From the Copenhagen Accord to efficient technology protocols

As the Copenhagen Conference of Parties (COP) failed to negotiate a binding Post-Kyoto agreement, an alternative is proposed based on the Copenhagen Accord (CA). The CA, as endorsed by COP16 in Cancun, aims to combat global warming with differentiated reduction targets of greenhouse gas emissions and by mobilizing resources supporting adaptation and carbon-free technology in developing countries (DCs). Using a special version of MERGE, we study the global implications of the CA postulating extensions of the Accord in the direction of Technology Transfer Protocols (TTPs). We assess scenarios needed to reach sustainable climate targets under such Protocols. It is shown that without binding commitments for DCs, the warming target of 2 °C will be exceeded with a probability above 50%, even if Annex B countries eliminate their emissions. However, moderate commitments of DCs (when they reach sufficient economic development), make the 2 °C scenario feasible. TTPs combined with binding emission reduction targets thus provide a mechanism to reduce climate change damages, and may generate significant secondary benefits. For example, the reduced tax-subsidy scenario (RTS20) has 77% to 40% chances to remain below 2 °C of warming and an undiscounted cumulative gross domestic product (GDP) cost of 0.75% relative to baseline (not accounting for the benefits of avoided damages).