Government Climate Scenario Roundtable on Future Risk

If you hear climate scenario analysis and switch off, you are not alone. But the basic question is one every government should ask: if the climate changes faster, hits harder or costs more than expected, will today’s decisions still hold up? That was the purpose of a cross-government roundtable held during London Climate Action Week, where the Government Actuary’s Department worked with the Institute and Faculty of Actuaries to bring together representatives from eight government organisations. According to GAD, the aim was simple but important: share experience, compare common problems and look at how climate scenarios can help shape policy and long-term decisions across government.

This matters because climate risk does not sit neatly inside one department. It affects economic performance, infrastructure, public services and national security. So while climate change is often talked about as an environmental issue, civil servants increasingly have to treat it as an everyday planning issue too. **What this means** is that when officials talk about resilience, they are really asking whether public systems can keep working under pressure. Scenario analysis gives them a way to test that before a crisis arrives, rather than after one.

One of the most useful ideas raised at the event was the difference between a scenario and a forecast. A forecast tries to say what is most likely to happen. A scenario asks a different question: what happens if the future turns out harsher, less stable or more extreme than the central expectation? Actuaries often use scenarios to test decisions against severe but plausible futures rather than one neat middle case. That matters for climate policy because long-term risk rarely behaves in a tidy, predictable way. If government plans only for the most comfortable version of the future, it can end up exposed when reality is tougher.

Many departments already use scenario-based tools for horizon scanning, which is a structured way of looking ahead for emerging risks, and for strategic risk planning. So the roundtable was not about inventing something brand new. It was about asking how these methods could be used more consistently when policy is written or public money is committed. The Institute and Faculty of Actuaries also shared insights from its contribution to HM Treasury’s Green Book discount rate review, which is about how government values future costs and benefits. That work explored whether very long-term, highly uncertain and potentially transformational decisions should be judged differently from routine investments. The discussion showed why many officials think the answer may often be yes.

From there, the conversation turned practical. Participants discussed where climate uncertainty is already taken seriously, where it can still be overlooked, what stops wider use of climate scenarios and what would help departments use them better. That may sound dry, but it gets to the centre of how policy succeeds or fails. Good analysis is not enough on its own. It also needs clear governance, usable tools and teams willing to share methods instead of working in isolation. The value of a roundtable like this is that it gives organisations a chance to compare what works, learn from each other and avoid repeating the same mistakes in separate corners of government.

GAD also brought a case study from its separate work with the Ministry of Justice on overheating risk across the prison estate. This looked at the possible effects of rising temperatures on prisons and showed how scenario analysis can help officials examine long-term risks, test possible responses and support practical decisions under uncertainty. **What this means for you as a reader** is that climate planning is not only about emissions targets or distant global summits. It is also about whether existing public buildings are safe in hotter summers, whether staff and residents are protected, and whether governments are acting early enough to avoid bigger problems later.

There was one detail from the day that made the whole subject feel especially immediate. Matt Gurden, Deputy Government Actuary, said the roundtable took place during a period of extreme heat and had to move to a hybrid format after a Met Office red heat alert. A meeting about climate risk was itself disrupted by climate conditions. That is why this story matters beyond Whitehall process. The shared direction from the roundtable was that stronger use of climate scenarios across government will need better governance, stronger analytical tools and closer collaboration between organisations. Put plainly, long-term decisions work better when governments stop pretending the future comes in only one version.