One seemingly minor and unreported component of the recent UN climate talks in Doha highlights the drawbacks of old-school scientific assessments and the need to modernize the IPCC process. It is especially relevant given last week's leak of draft IPCC reports and the ensuing discussion about changing the arduous and close IPCC assessment process.

IPCC Chair Rajendra Pachauri addresses the COP18 in Doha

Starting in at the Copenhagen meeting three years ago, the countries participating in the UN climate talks agreed to regularly revisit whether a +2°C warming 'limit' is sufficient to avoid dangerous impacts of climate change. The text of that agreement, and all since, have specifically indicated a +1.5°C threshold should be evaluated.

Put aside for a moment whether you or I think either goal is attainable; in fact, the final Doha text itself raises that question right off the start:

Noting with grave concern the significant gap between
the aggregate effect of Parties’ mitigation pledges in terms 
of global annual emissions of greenhouse gases by 2020 and aggregate emission pathways consistent with having a likely chance of holding the increase in global average temperature below 2 °C or 1.5 °C above pre-industrial levels

The parties to the UN climate talks agreed to evaluate the temperature targets, because of concern in developing nations, particularly the small island states, that +2°C warming will lock-in unacceptable climate impacts. The outstanding question at Doha and the last meeting in Durban was how will those evaluations happen.

At the bottom of the agreed Doha text, after all the publicized issues like the Kyoto extension, long-term agreements and financing arrangement, is the plan:

79.  Decides that the review should periodically assess, in accordance with the relevant principles and provisions of the Convention, the following:
(a)  The adequacy of the long-term global goal in the light of the ultimate objective of the Convention;
(b)  Overall progress made towards achieving the long-term global goal, including a consideration of the implementation of the commitments under the Convention;


After outlining some of the logistical details, come the guts (italics are mine):

86.  Decides to establish such a dialogue under the guidance of the subsidiary bodies on aspects related to the review in order:
(a)  To consider on an ongoing basis throughout the review the material from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change as it becomes available, as well as relevant inputs referred to in decision 2/CP.17, paragraph 161, that are published after the cut-off date of the Fifth Assessment Report, through regular scientific workshops and expert meetings and with the participation of Parties and experts, particularly from the Intergovernmental Panel on Climate Change;


The Doha text effectively states that the UN climate policy process requires something more "nimble" than the IPCC. This matches what many in the climate science and policy community have been saying since the last IPCC assessment was published in 2007. The IPCC is an amazing institution, with no real parallels in science. In what other field have the countries of the world agreed to gather panels of experts to conduct exhaustive, lengthy assessments of all the science on a subject, which are then open for review by anyone in the science community and representative of the government, and all on a volunteer basis? The IPCC process, though hardly perfect, is without peers.

It is also very old school. The IPCC is a product of the late 1980s, before the internet, before smart phones, and before we had overwhelming evidence for a human role in climate change. The IPCC assessments are the product of a long, exhaustive writing and reviewing process. They can only be completed every few years, and can not reflect research conducted within 1-2 years of when the assessment are published. As such, they do not cover some recent findings or advances in modelling. The process, and the desire for consensus, also leads to conservative decisions, like the decision to exclude then-uncertain contributions from ice sheet melt in the summary estimates of future sea level rise in the last IPCC assessment.

That sea level rise dispute likely drove the inclusion of the published after the cut-off date to the Doha text. The projections of sea level rise published after, and in response to, the last IPCC assessment presents a very different future for low-lying small island states, many of which were already lobbying for the lower temperature target. There's a good chance the lack of a permafrost methane feedback in most climate models, and hence conclusions of the upcoming fifth IPCC assessment ("AR5"), will lead to similar disputes after that assessment is released.

This raises an important question:  If the UN negotiation process requests quicker turnaround reviews of climate science, reviews conducted by IPCC members, why continue doing full IPCC assessments after AR5? It is time to move to shorter, faster targeted reviews of key outstanding issues and areas of scientific uncertainty.