Cross-government roundtable explores climate scenarios

Climate and risk specialists from the Government Actuary’s Department (GAD) partnered with the Institute and Faculty of Actuaries (IFoA) to host a cross-government roundtable on climate scenarios.

The event, during London Climate Action Week, brought together representatives from 8 government organisations to

• share experience
• identify common challenges
• explore how climate scenarios can support policymaking and long-term decision-making across government

Building resilience through scenario analysis

Government departments increasingly recognise that climate risks affect economic performance, infrastructure, public services and national security.

Many departments already use scenario-based tools for horizon scanning and strategic risk planning. Attendees explored how these approaches could be used more consistently to inform policy and investment decisions.

The event opened with a presentation on how actuaries use scenarios, as opposed to forecasts, to test decisions against severe but plausible futures rather than a single central case.

The IFoA also shared insights from its contribution (PDF, 1.19KB) to HM Treasury’s Green Book Discount Rate review, exploring how long-term, transformational and highly uncertain decisions might be appraised differently from routine investments.

Sharing experiences

Drawing on a range of departmental perspectives, participants took part in facilitated discussions to consider

• where climate uncertainty is already well considered, and where it can be overlooked
• the barriers to wider use of climate scenarios across government
• what would help ensure climate scenarios are best used to support effective decision-making

GAD also shared a practical case study, drawn from separate GAD work with the Ministry of Justice
on prison estate overheating risk. This work examined the potential impact of rising temperatures on the prison estate. It illustrated how scenario analysis can help organisations assess long-term risks, test potential interventions and support practical decision-making in the face of uncertainty.

The roundtable provided a structured opportunity for organisations to compare approaches, share practical experience and identify common challenges.

Discussions highlighted a shared interest in strengthening the use of climate scenarios across government, particularly through improved governance, better analytical tools and increased collaboration between organisations.