Since then, many scientific and policy initiatives worked on identifying quantitative indicators at the country level and in the aim of informing the UNFCCC negotiations. To date, these efforts partly failed for three main reasons. First, and this is a long debate in science in general, it is very difficult to identify the “right” indicators, meaning the ones that adequately describe adaptation (i.e. not only the GDP-related dimensions) and can be applied to all countries. Second, even if these indicators are identified, the problem of data availability/gap limits any systematic assessment. Third, the adaptation science community increasingly challenges the relevance of the country-level entry point to describe adaptation efforts, rightly arguing that national statistics are not well-suited to represent the diversity of local situations where, actually, adaptation mostly happens. In the end, it remains difficult to answer whether the global society is on track to climate adaptation or on a path towards higher climate risk levels.

We started to think about this question right after the Paris Agreement. We initially thought that because existing databases are inadequate to assess adaptation progress in a sound and comprehensive way (i.e. across adaptation dimensions and across scales), other types of indicators/data are needed to reflect adaptation as it truly happens on the ground. For instance, satellite imagery diachronic analyses could help highlight trends on built assets’ exposure to sea-related hazards, for example by comparing decadal changes in the spatial footprint of built assets (e.g. more or less close to the shore and in elevated areas) to observed and possibly projected shoreline changes and marine flooding expansion. We however quickly realized that such analyses would require huge technical means that we did not have —IDDRI, my institution, is not the NASA!— and that, more problematic, not all adaptation aspects can be concretely seen on the ground —take the example of the design and implementation of policies…. We therefore decided to shift to another approach consisting of a structured expert judgment exercise, “structured” meaning that there is a robust scientific method behind it. This shift has been driven by the fact that in the meantime, some of us experienced such a method to assess risks from sea-level rise to low-lying coasts in the 2019 IPCC Special Report on Ocean and Cryosphere (see burning embers in chapter 4). This made us realize that structured expert judgment methods allow two things that actually became instrumental to our paper: first, not be constrained by the non-availability of quantitative data and rather rely on a wider diversity of sources of information (also qualitative, not only published material, human experience, etc.); second, be able to reflect a local-scale perspective into global-scale assessments.

It then took a couple of months to establish the methodology —that we call the Global Adaptation Progress Tracker, GAP-Track— and then about a year to apply and refine it with the expert group composed of the authors of the Nature Climate Change paper. Results are presented in this latter and additional elements are discussed in the associated Research Briefing, so I won’t come back to this here. Rather, I would like to stress the following point: getting funds for conducting research that is primarily based on an intuition (“it should work, that’s worth trying”) but without any prior proofs that it will land for sure on valuable outcomes, is particularly difficult. Yet, intuition is key to innovation in scientific research, not only in hard but also social sciences. We have been extremely lucky that two French partners (the French Development Agency, AFD, and the French Energy Agency, Ademe) took such a risk and provided us with ~220 000€ in total. This happened because IDDRI has a long history of collaboration with AFD and Ademe, which allowed us to engage into deep and regular discussions on why betting on a structured expert judgment method to assess adaptation efforts globally was promising in terms of informing key international climate policy processes such as the GGA framework and the Global Stocktake —a UNFCCC 5-year cycle to assess collective progress made toward meeting the goals of the Paris Agreement. This financial support simply made it possible for us to showcase to the international policy community the added-value of the approach, the scientific work having been paired with regular dialogues with people engaged in the UNFCCC negotiations.

Now that the scientific results are out and demonstrate that critical policy-oriented outcomes can be delivered in a relatively short period of time, we hope that at the next Conference of the Parties to the UNFCCC in end-November this year (COP28), the climate policy community will send a green-light to apply the GAP-Track approach to a broader set of key risk areas and adaptation challenges than only coastal ones —that we used until now as a demonstrator of the feasibility of the structured expert judgment method. This would mean considering adaptation in other socio-geographical systems (e.g. cities, rural areas, mountain areas, arctic environments) and sectors (e.g., health, water and food security) to assess global adaptation efforts in a more comprehensive way, and on time to feed the second Global Stocktake in 2028. Now, let’s see what will happen in the coming weeks…