I argued in this post earlier this month that the upcoming Paris Agreement climate change negotiations will require parties to confront two simultaneous dynamics. On the one hand, the strategy of allowing each country to determine their climate change mitigation benchmarks (Intended Nationally Determined Contributions or INDCs) has been successful in fostering participation in the Paris Agreement framework, particularly among developing countries who might have scoffed at multilaterally-created mitigation rules and norms. On the other hand, we know that the combined impact of the INDCs (and at this point most have been submitted) is not enough to meaningfully combat climate change.
This aggregate shortcoming will force negotiators to consider how INDCs should evolve across time. Clearly a static commitment to, for example, reduce GHG emissions by 22% by 2030 (in the case of Mexico's INDC) would expire in 2030, and may prove woefully inadequate as climate science provides more feedback on the relationship between GHGs and the climate system. So at what point would these INDCs need to be revised, and with what criteria should revised INDCs be evaluated?
One proposal being floated around suggests a five-year submission and evaluation cycle in which countries must progressively submit more ambitious INDCs than the previous five-year commitment. Something like the following:
Five year intervals probably strike the right balance between the need to re-evaluate mitigation actions and the political capital required to address the issue on a periodic basis. What is lacking from this proposal though, is any kind of stick that would complement the carrot of determining mitigation commitments nationally. The INDCs appear to be a good model if securing broad-based participation is your objective, but so far the approach isn't doing enough to reduce climate impacts. There is a risk that the Paris Agreement - by endorsing the INDC approach and cementing it as the global climate paradigm - will perpetuate an inadequate global response.
A 5-year INDC cycle might rest on the hope that the momentum created by the INDCs does enough to make countries address their own emissions that they recognize and pursue the benefits of a climate friendly agenda on their own, and step up their mitigation efforts out of self-interest. It's a plausible, if tenuous, path to success.