The Baku to Belem Roadmap to 1.3T is about mobilising and directing climate finance, yet it says relatively little about how the underlying climate risks are to be measured, compared and fed into economic decision-making. For countries already grappling with rising debt, tightening fiscal space and escalating climate impacts, this is no longer a technical issue, it is also central to both their ability to plan and their leverage in climate finance negotiations.
The report does acknowledge the role of exposure indices and other related metrics but treats them largely as supporting diagnostics. In practice, they need to be understood as core infrastructure for the climate finance system. Without credible, country developed metrics that show how climate hazards are affecting growth, sectoral output and public finances, demands for adaptation finance, loss & damage support remain vulnerable to being dismissed as “aspirational”. With such metrics, especially when grounded in transparent methodologies, these demands can be reframed as responses to quantifiable risks.
Recent work by ICRIER on Estimating the Future Cost of Adaptation for India provides useful illustration of climate risk measurement. The study develops exposure indices for five key climate stresses, namely rainfall variability, floods, droughts, heat stress and sea level rise using national observational data and climate projections. These indices, scaled between zero and one, capture how exposed the country is to each hazard. They are then used to weight sector-wise damage functions drawn from the literature, producing estimates of how much climate change is already shaving off GDP and how this might evolve under different scenarios. Further, it is not enough to measure today’s exposure, countries will increasingly need regularly updated exposure indices linked to standard climate scenarios, so that future trajectories of risk can be built into fiscal planning and long-term investment decisions.
Exposure indices combine long-term climate variables (rainfall patterns, temperature extremes, sea-level trends) with information on who and what (people, land, infrastructure, ecosystems) gets exposed. Flood indices, for example, can blend the share of land inundated with the proportion of population affected, drought indices can draw on precipitation anomalies over several decades, heat indices can capture both the frequency of “heat days” and the intensity of maximum temperatures, and sea-level exposure can integrate coastal elevation and population density. This is directly relevant to the growing ecosystem of climate-related financial sector methodologies. As more climate-related financial sector methodologies are being developed, from stress testing to integration of climate scenarios into macroeconomic modelling and budget forecasts, countries with the least capacities will benefit from institutionalised international collaboration and peer-learning networks, recognising existing challenges such as lack of standardised and quality data resulting in underestimation and only partial measurement of climate-related risks. If these tools evolve without a parallel investment in exposure metrics and data systems, there is a risk that they will function primarily as compliance exercises imposed from outside, rather than as instruments vulnerable countries can use to strengthen their own negotiating position.
At the same time, taking exposure indices seriously exposes just how demanding this agenda is. Even in relatively data-rich settings, constructing robust indices requires long, consistent climate time series data that is harmonised across multiple agencies, high-quality socio-economic and sectoral data at sub-national level, and enough empirical work to link climate variables to outcomes such as labour productivity, health, ecosystem services etc. Many low-income countries are still struggling with basic data gaps for rainfall, temperature, land use or coastal elevation, and their national statistical systems are already stretched thin. Expecting them to match the analytical standards implied by stress-testing and scenario-based fiscal planning, without targeted support, risks deepening existing asymmetries in the climate finance system.
This is precisely where the Roadmap could have been more forward-looking. Rather than a generic call for better vulnerability metrics, it could have recognised climate risk analytics, including exposure indices, as a global public good that requires its own financing and governance arrangements. The emerging GIRI model can be seen as a promising first step in building this kind of shared infrastructure for climate risk measurement, but it will need to be complemented by sustained investment in country-owned data systems and analytics. An ambitious extension of the Baku to Belem agenda would propose an international facility for climate risk measurement and modelling, with three concrete pillars: grant-based support for data collection and statistical capacity in vulnerable countries; open-source toolkits for building exposure indices and embedding them in macro-fiscal and financial models, and structured peer-learning platforms where countries can adapt and improve these tools in practice.
Multilateral development banks and UN agencies would also need to adjust their role. Beyond project finance and policy lending, they could be mandated to co-develop and adopt standards for climate risk measurement, aligning their own risk assessments and country strategies with nationally generated exposure metrics wherever possible. Over time, such convergence could help reduce the current fragmentation of approaches, and limit the space for opaque modelling choices that systematically understate the risks faced by climate-vulnerable states.
Ultimately, this is about credibility as much as capacity. A climate finance architecture that claims to mobilise trillions, but continues to operate with only a partial view of the risks it is addressing, will struggle to convince that resources are being directed where they are most needed. Bringing exposure indices and related climate risk measurement tools into the centre of the Baku to Belem agenda would signal a shift from ad hoc, narrative-based justifications towards a more disciplined, evidence-based approach to needs and priorities. It is not a substitute for the hard political choices on revenue sources or instruments, but it is a necessary complement without which even the most ambitious Roadmap risks remaining a statement of intent rather than a guide to action.
(Views expressed are the author’s own and do not reflect those of ICRIER)
