Why Ancient Climates Are Missing From Modern Climate Policy

When policymakers sit down to write climate policy, they almost always reach for the recent past: satellite records, weather stations, and model projections covering roughly the last 150 years. But the climate system has been behaving for millions of years, and the geological archives that preserve that deeper history — ice cores, lake sediments, tree rings, and ocean mud — contain information about climate extremes, tipping points, and natural variability that no instrumental record can match. A new study published in Geoscience Communication has now asked, for the first time, why this wealth of palaeoclimate evidence so rarely makes it into the rooms where climate decisions are actually made, and what could be done to change that.

The research, led by Laura Boyall of Royal Holloway University of London and Bangor University, together with Alice Milner, Klaus Dodds, and Celia Martin-Puertas, took an unusually direct approach: they interviewed the people on both sides of the divide. Six policy advisors from UK Civil Service departments — including the Department for Energy Security and Net Zero, Defra, the Foreign, Commonwealth and Development Office, and the Environment Agency — and five senior palaeoclimate scientists from UK universities were questioned in semi-structured interviews about how they perceive, produce, and use evidence about past climates. The transcripts were then analysed using reflexive thematic analysis, with codes developed inductively from the data and grouped into three overarching themes: evidence, context for climate change, and temporal resolution.

The most striking finding concerns where decision makers actually get their climate information. The interviews revealed what the authors describe as an evidence hierarchy, and at its very top sit the assessment reports of the Intergovernmental Panel on Climate Change. Every single decision maker interviewed named the IPCC as their preferred first source, citing its role as a single, trusted synthesis of thousands of peer-reviewed studies, its rigorous review process, and — for those working on international policy — its global acceptance. Below the IPCC came boundary organisations and knowledge brokers such as the Met Office, the World Meteorological Organisation, World Weather Attribution, and the Climate Change Committee, followed by commissioned research, government websites, and only then peer-reviewed journal articles. Expert advice and seminars sat at the very bottom of the hierarchy, used rarely despite being valued when they occur.

That lowly position for journal articles is significant, because it is precisely where most palaeoclimate evidence lives. The study explains that academic papers are written by scientists for scientists, dense with methodological detail, specialist terminology, and field-specific background that makes them slow to digest for officials working under tight deadlines. Single studies also need to be interpreted alongside a wider body of literature to be meaningful, making them less directly useful than syntheses. And there is a more mundane obstacle: many relevant papers sit behind paywalls that policy departments cannot afford to breach, pushing officials toward freely accessible alternatives. In other words, the default dissemination format of palaeoclimate research is almost perfectly misaligned with how its potential users actually consume evidence.

On the substance, there was genuine agreement between the two groups. Both scientists and decision makers agreed that palaeoclimate has a real role to play, above all in contextualising current and future warming. Records of past climates show how the climate system behaves over centuries and millennia, revealing the full range of natural variability and the frequency of rare but high-impact events that the short instrumental record simply cannot capture. Without that longer baseline, the study notes, policymakers risk systematically under- or over-estimating the likelihood of extremes, misidentifying the drivers of climate variability, and failing to anticipate thresholds or abrupt transitions. Palaeoclimate scientists interviewed for the study described contributing summaries of ecosystem tipping points and reconstructions of past water availability directly to the Foreign Office, and one remarked that everything we know about the climate system is ultimately based on understanding the past.

Yet the interviews also exposed a stubborn practical problem: time. Policy operates on electoral cycles and planning horizons of a few years to a few decades, while many palaeoclimate reconstructions resolve change only on centennial to millennial scales. One decision maker described hitting a wall of insufficient granularity, unable to extract from a coarse reconstruction any information useful for, say, mapping flood risk from a rapid-onset rainfall event. Another noted bluntly that if a graph of past climate looks like a straight line at 100-year resolution, a policymaker has little they can act on. Interestingly, the study suggests the problem is partly one of perception rather than fact: not all decision makers were aware that palaeoclimate reconstructions can achieve decadal or even annual resolution. The mismatch, the authors argue, reflects a failure to communicate why longer timescales matter, not an inherent irrelevance of the data.

Communication emerged as the principal barrier across all three themes — both the format in which palaeoclimate is disseminated and the messaging about its relevance. The study situates this within a well-documented critique of the so-called deficit model, the assumption among many scientists that publishing a paper initiates a linear flow of knowledge into policy. In reality, evidence use is indirect and shaped by institutional cultures, trust, timing, and political priorities. One decision maker even noted a preference for publicly funded research, treating public funding as a safeguard against perceived bias. The academic reward structure compounds the problem: under the UK’s Research Excellence Framework, traditional publications carry a 60 percent weighting in institutional assessments while impact beyond academia counts for just 25 percent, giving researchers little institutional incentive to engage with policy at all.

The authors do not leave the problem hanging. They distil a set of actionable recommendations aimed squarely at palaeoclimate scientists. First, write policy briefs: short, jargon-free summaries of the policy-relevant parts of a study, which surveys in other disciplines have found to be among the most effective tools for crossing the science-policy interface. Second, pursue transdisciplinary collaboration, embedding palaeoclimate evidence within research that already incorporates the socioeconomic and political dimensions that shape real decisions. Third, seek science-policy training, ideally through secondments and placement schemes such as those listed by the UK Government Office for Science, which build networks and first-hand understanding of how evidence is actually used. Fourth, and most importantly, embrace co-production — working with decision makers and boundary organisations such as the Met Office from the very start of a research project, so that the questions asked, the resolutions targeted, and the outputs produced are aligned with genuine policy needs from day one.

There are encouraging signs that the tide may be turning. Within the IPCC’s most recent assessment report, palaeoclimate content was deliberately distributed throughout the document rather than confined to standalone chapters, meaning that officials absorbing the report encounter long-term climate context naturally, without needing to seek it out. The study also points to the influence of individuals: decision makers with a palaeoclimate background could far more readily identify where such evidence would be useful, and past Chief Scientific Advisers — including Defra’s former CSA Gideon Henderson, an Earth-system scientist — have brought exactly that training into government. The authors acknowledge their study’s limitations, including a small sample of eleven interviews and a UK-specific focus, and they call for similar work across other national and supranational policy environments and a broader range of stakeholder groups. But the core message is clear and urgent: the past holds evidence the future desperately needs, and the barrier is not the science — it is the conversation around it. Fix that, the researchers argue, and palaeoclimate could finally take its place alongside instruments and models in the evidence base on which climate policy is built.

Subject of Research: Barriers and facilitators to integrating palaeoclimate evidence into UK climate policy decision making

Article Title: Barriers and facilitators for using palaeoclimate evidence in UK climate decision making

Article References: Barriers and facilitators for using palaeoclimate evidence in UK climate decision making. (n.d.). https://doi.org/10.5194/gc-9-275-2026

Image Credits: AI Generated

DOI: 10.5194/gc-9-275-2026

Keywords: palaeoclimate, climate policy, science-policy interface, UK Civil Service, IPCC, evidence hierarchy, knowledge exchange, co-production, policy briefs, climate decision making, proxy records, Geoscience Communication