The ECOnomic Evaluation for Climate Action (ECO-CHICA) consensus guidance is now on SSRN, with the scoping review and methodological deep dives available alongside it. Here is what they say, and why the question in the title is harder than it looks.
Climate action does more than cut emissions, help control flooding, or prepare cities for extreme heat. The health gains can be substantial: reduced water induced infections anf fewer heat strokes and respiratory diseases, for example. But these health gains can often be neglected in the appraisals that decide which policies go ahead.
In our recent ECOCHICA research project, we investigate the methods that have been applied to value these health impacts and found big discrepancies. Part of the problem is that health economists and environmental economists value the same avoided death differently. Neither is wrong— it’s that they are both using the language of their respective disciplines, rather than a shared vocabulary. Even within disciplines, there is wide variance in the methods used.
When we went looking for how this plays out in the published evidence, the divergence was vast. Across the studies we reviewed, the value of a statistical life ran from about $0.6 million in one setting to more than $13 million in another. Estimates of the social cost of carbon ranged from roughly $51 to $228 a tonne, driven largely by which model the analyst applied. Most studies said they took a “societal perspective”. Fewer said what they meant by it. The lowest life values turned up in lower-income settings, and the literature barely looked at Africa at all.
None of this means the numbers are necessary wrong. It means the methods were built from different sources and for different purposes, and they co-exist in ways that often do not align together. What this means in practice is that the same low-emission zone can look like good value or poor value depending on whose framework you reach for. For anyone trying to compare options or add up evidence, that is not a rounding error.
The ECO-CHICA guidance is based on consensus and, thus, it does not choose a single winner. But it does produce something more useful after analysing the state of the question/landscape. It suggests that methods are applied consistently, chosen explicitly, and matched to the budget the decision affects. If the impact lands on a health budget, value it in the terms that budget already uses, e.g., the value of a QALY or a DALY; if it lands on another department or organisation, use the value that body relies on to make its own decisions. What undermines comparability is not that these values differ, but that the choice between them often goes unstated. Working through targeted reviews, five focused deep dives, and a three-round Delphi process with practising health economists, environmentalists, climate scientists, etc. (46 of the 84 invited completed every qualifying round), the project arrived at 11 guidance statements across two domains: how to measure and value health impacts, and the wider methods that surround that valuation. Two foundational statements anchor each domain. The aim is not to mandate one approach but to make the choice explicit, justified, and reported in the open.
Three sets of materials are now available.
- The consensus guidance is the first consensus-based framework for valuing the health impacts of climate action. It covers mortality and morbidity valuation, the social cost of carbon, discounting, equity, uncertainty, and environmental spillovers, and it is written to be read selectively rather than cover to cover. Start with the summary table and the two foundational statements.
- The scoping review maps what analysts are doing. It draws on 121 studies and is honest about the state of play: benefit-cost analysis dominates, the value of a statistical life is the workhorse metric, and transparency about sources and adjustments is patchier than it should be despite the problems each present.
- The deep dives put under the microscope five contested highly relevant issues when estimating the health impact of climate action: the social cost of carbon, the value of a statistical life, equity and distribution, macroeconomic modelling, and discounting. This is where the disagreements live, and where the guidance draws its evidence.
We are not pretending the guidance solves the disagreements. But disagreeing in the open, with reasons attached, is a good deal better than disagreeing by accident. If you value health impacts in climate appraisal, or commission the people who do or are interested on where we are with this subject, these are for you.