Whitehall’s climate planning is moving into a more practical phase. On 24 July 2026, the Government Actuary’s Department and the Institute and Faculty of Actuaries said they had brought together eight government organisations during London Climate Action Week to compare how climate scenarios can guide policy and long-term decisions. (gov.uk) The point of the exercise was straightforward. As GAD explained, scenarios are not predictions but a way to test decisions against severe yet plausible futures instead of relying on one central forecast. That matters when the risks in question include damage to infrastructure, weaker economic performance, pressure on public services and wider security concerns. (gov.uk)

The timing gave the meeting unusual force. London Climate Action Week ran from 20 to 28 June 2026, and the roundtable was shifted into a hybrid format during a spell of extreme heat after red warnings and alerts were issued for London and other parts of southern England. The weather was not background noise; it was a live reminder that climate risk can already disrupt how government works. (london.gov.uk) For Eco Current readers, that is the useful shift in focus. Climate scenarios sound technical, but their value is immediate: they help officials ask whether a policy, a building upgrade or a service plan still holds up when hotter summers, flood shocks or supply disruption stop being edge cases. (gov.uk)

That urgency sits against a difficult national picture. In its 2025 report to Parliament, the Climate Change Committee said UK preparations for climate change remain inadequate, with no outcome rated good for adaptation delivery and 12 of 46 outcomes scored as insufficient. The committee also said adaptation is still only weakly joined up across departments, sectors and spending decisions. (theccc.org.uk) The same report is clear about what is at stake. Public assets and critical services need to cope with current and future weather without costly retrofitting, yet the UK is already seeing rising disruption from heat and flooding on rail and road networks. That makes climate scenario work less of a specialist exercise and more of a basic test of whether the state is planning for the conditions already taking shape. (theccc.org.uk)

GAD’s Ministry of Justice case study shows what this looks like when it is tied to real-world assets. Work published in April 2026 examined how climate risks could affect the justice system across the 2030s, 2050s and 2080s, covering prisons, courts, probation and supply chains. The MoJ’s latest climate resilience plan adds a stark baseline: 89% of prisons are at high flood risk and 65% of all buildings are at high or very high overheating risk under a 2°C warming scenario. (gov.uk) The response being tested is practical rather than abstract. The MoJ says it will carry out further scenario analysis, pilot flood measures including Sustainable Drainage Systems, and trial passive, fabric-first steps to cut overheating without heavy dependence on mechanical cooling. That is the sort of evidence-led adaptation other departments can use now, rather than waiting for a larger failure to force the issue. (gov.uk)

The actuarial contribution matters because public investment rules still decide what gets built, repaired or delayed. In its November 2025 paper for HM Treasury’s Green Book review, the Institute and Faculty of Actuaries warned that viable long-term projects can fail to progress because current discount-rate guidance and over-reliance on cost-benefit analysis can undervalue uncertain, long-duration benefits. The paper argues for more use of scenario analysis and closer attention to the costs of inaction. (vle.actuaries.org.uk) That lines up with the wider science. The IPCC says adaptation decisions can still be made under uncertainty, using approaches such as robust decision-making and dynamic adaptation pathways rather than waiting for a perfect forecast. For departments managing prisons, hospitals, transport links or flood-prone estates, the message is plain enough: uncertainty is a reason to test options harder, not a reason to delay them. (ipcc.ch)

The roundtable itself ended with familiar but important themes: better governance, stronger analytical tools and closer collaboration across government. Those only become meaningful if they change how projects are appraised, how estates are upgraded and how climate risk moves from a policy note into everyday operational decisions. (gov.uk) A sensible next step, based on the direction already set out by the Climate Change Committee and the Ministry of Justice, would be common scenario standards across Whitehall, clearer trigger points for heat and flood action, and routine checks that major spending choices still work in a hotter climate. The roundtable did not settle those questions on its own, but it did show that parts of government are beginning to treat climate resilience as present-day public service planning rather than a distant add-on. (gov.uk)