The Danger of Using Just One Climate Scenario

When organisations start looking at climate adaptation, one of the first questions is: what future are we actually planning for?

It’s tempting to reach for a single set of climate projections – perhaps the latest Met Office UK Climate Projections (UKCP) under one Representative Concentration Pathway (RCP) or Shared Socioeconomic Pathway (SSP) – and build your plans around that. It feels tidy. It gives a number to work with. But relying on just one scenario is a risky strategy.

Here’s why.

1. Climate Futures Are Not Linear Predictions

RCPs are scenarios, not forecasts. They represent a range of possible greenhouse gas concentration pathways and their likely impacts. The Met Office (and other modelling centres) provide multiple scenarios because the future depends on global political, social, and technological choices – things that are inherently uncertain. The Met Office emphasises that emissions scenarios are “what-if” storylines, not predictions. Their value lies in stress-testing strategies against a range of futures, helping decision-makers understand how risks might unfold under different circumstances.

If you build your adaptation plan on only, say, RCP8.5 (a high-emission scenario), you risk designing infrastructure and policies that are unnecessarily costly if emissions actually peak earlier. On the flip side, if you plan only around RCP2.6 (a low-emission pathway), you may under-prepare for more severe impacts.

2. Local Impacts Vary More Than You Think

Even within the UK, the same RCP can play out differently across regions. A single scenario can’t capture the uncertainty in rainfall distribution, seasonal shifts, or extreme weather frequency. For example, summer droughts in eastern England may be more intense under certain model runs, while winter flooding in the West Midlands dominates under others.

If you base decisions on just one run, you risk missing the plausible range of outcomes your site or community could face.

3. Overconfidence is an Organisational Risk

Boards and senior leaders like certainty. Presenting one neat projection – “by 2050 summers will be X degrees warmer and rainfall will drop by Y%” – can lead to a false sense of precision. But overconfidence in a single trajectory can actually increase organisational vulnerability, because plans won’t be stress-tested against surprises.

4. Regulators and Investors Expect a Range

Frameworks like TCFD and ISSB standards are clear: you need to test your resilience against more than one climate pathway. Investors, insurers, and regulators increasingly want to see that organisations have considered both best case, worst case, and middle-of-the-road futures. A single-scenario approach doesn’t cut it in disclosure or credibility terms.

5. Adaptation Requires Flexibility

The most effective adaptation strategies are those that are robust across multiple futures. That doesn’t mean trying to predict the “right” one – it means building flexibility, monitoring triggers, and updating plans as new information emerges.

Think of it like sailing: you don’t pick one possible wind forecast and lock your rudder in place – you chart a course that allows you to tack as conditions shift.

The Better Way Forward

Instead of anchoring on one Met Office RCP scenario:

• Use all the scenarios and never use one in isolation: or at least four contrasting pathways (low vs. high emissions) for stress-testing.

• Look at uncertainty: not just averages, but spreads and extremes.

• Plan for robustness: prioritise actions that make sense under most futures (e.g. water efficiency, flood resilience, green infrastructure).

• Build in review points: update your adaptation strategy as new science and policy pathways emerge.

What Boards Should Ask

When reviewing climate adaptation plans, challenge teams with simple questions:

• Have we looked at both higher-risk and lower-risk futures?

• Are we stress-testing plans against a range of plausible conditions?

• Where are the “no-regret” actions that work in any future?

• How often will we review and update our assumptions?

Final Word

Climate adaptation is not about finding the answer in the data – it’s about preparing for a future that is inherently uncertain. Using just one scenario might feel neat, but it risks leaving organisations blind to the very risks they’re trying to manage.

The goal is resilience, not prediction. And resilience requires a wide-angle lens.

How Resilient Horizons Can Help

At Resilient Horizons, we specialise in turning climate uncertainty into actionable strategies for boards and leadership teams.

We help organisations by:

• Scenario testing: Using a range of climate projections (not just one) to stress-test your estate, operations, or supply chain.

• Board-ready insights: Translating technical climate data into clear, decision-relevant messages for senior leaders.

• Adaptation roadmaps: Identifying “no-regret” measures that deliver value across multiple futures.

• Governance and compliance: Aligning your approach with frameworks like TCFD and ISSB, ensuring resilience planning also meets investor and regulatory expectations.

• Review and refresh: Building in practical checkpoints so plans evolve as science and policy do.

Our goal isn’t to tell you which future will happen — it’s to help you be ready for whichever future does.