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Increase DEFRA budget and fund nature-based solutions

Green · what the evidence says

An independent, source-checked look at Green’s policy “Increase DEFRA budget and fund nature-based solutions” — what it would actually do across the things that affect your life. Every claim below quotes the source behind it. How this works.

Public finances & the next generation — Mixed picture

moderate · low confidence

The policy adds £1.5bn to public spending with no stated funding source, worsening the near-term fiscal position; but the evidence suggests much of this spending has the character of productive investment with long-run returns that could offset the initial cost. Whether the net effect on the debt path is positive or negative depends on whether projected benefit-cost ratios materialise and how the spending is financed.

The evidence

Biggest unknown: Whether the £1.5bn is funded (by tax, reallocation, or borrowing) and whether the projected benefit-cost ratios for nature-based solutions translate into real Exchequer savings at scale.

Our reading: For O12 the critical questions are: is the spending funded, and does it finance consumption or productive investment? On the first question, the policy states a £1.5bn budget increase with no identified funding source. In the near term this represents an unfunded spending commitment that adds to borrowing or requires cuts elsewhere — a negative for the debt path on standard fiscal accounting. On the second question, the evidence consistently characterises the proposed spending as productive investment rather than consumption. Projected BCRs of £4.62–£10 per £1 over 30 years, and annual avoided costs from flooding (£2.2bn, rising) and soil degradation (£1.2bn), suggest that if these returns materialise, the long-run fiscal position could be improved by more than the initial outlay. This is precisely the 'borrow to invest' scenario the O12 criteria says can improve long-run sustainability. However, the confidence in this positive long-run case is low for two reasons. First, the BCR figures come from varied sources (some commercial or advocacy-adjacent) and are not validated by OBR or IFS assessments of this specific package; they remain projected benefits, not guaranteed Exchequer savings. Second, a parliamentary committee has flagged that government NbS plans are at severe risk of delivery failure — if implementation is poor, the investment rationale collapses and only the near-term cost remains. The verdict is therefore 'mixed': a near-term worsening of the fiscal position (unfunded spending increase) that could convert to a long-run improvement if BCRs are realised, but with low confidence given delivery risk and the absence of any independent fiscal costing.

Prosperity & living standards — Helps

minor · moderate confidence

Investing £1.5bn in nature-based flood prevention, river restoration, and soil health is projected to reduce costly flood damage and improve agricultural productivity over the long term, but most gains are diffuse, slow-maturing, and partly dependent on delivery capacity that has historically been weak.

The evidence

Biggest unknown: Whether delivery institutions (Environment Agency, Natural England) have the capacity to deploy £1.5bn effectively at scale, given past warnings that NbS plans are 'at severe risk of failure' without adequate resourcing.

Our reading: The policy targets two well-evidenced drags on long-run living standards: flood damage (£2.2bn/yr and rising) and soil degradation (£1.2bn/yr). Both are real economic costs borne by households, farmers, and businesses, so reducing them would meaningfully improve prosperity. The projected benefit-to-cost ratios for natural flood management, peatland restoration, and woodland planting are substantial (up to 10:1, 4.62:1, and 2.79:1 respectively), and independent projections suggest NbS can raise agricultural productivity and create jobs — plausible pathways to improved living standards. These gains are real but long-horizon: woodland planting, peatland restoration and river restoration take years to decades to deliver their full economic benefit. Near-term, the main effect is public expenditure and some job creation in implementation; material productivity and flood-resilience gains accrue over 10+ years. A 2022 House of Lords committee found NbS ambitions 'at severe risk of failure' without adequate delivery capacity — this policy directly addresses that constraint by funding the EA and Natural England, which lends credibility to the mechanism. However, that same analysis warns that underresourced institutions historically struggled; £1.5bn is a significant uplift but delivery risk remains genuine. An additional limit is that conventional Treasury appraisal systematically undervalues NbS benefits, creating friction in scaling up effectively. The magnitude is rated minor rather than moderate because: the gains are diffuse across sectors and geographies; much of the return is non-monetised (biodiversity, amenity); realisation requires sustained institutional delivery over many years; and the £1.5bn, while substantial, is unlikely to eliminate flood or soil-degradation costs at population scale within a parliament. Confidence is moderate: the benefit-cost evidence is reasonably consistent across independent projections, but delivery uncertainty is high.

Clean environment & nature — Helps

moderate · moderate confidence

Funding the Environment Agency and Natural England while restoring rivers, tackling storm overflows, and monitoring soil health would materially improve water quality, biodiversity, and flood resilience — especially over the long term. The main caveat is that nature-based solutions take years to mature, and traditional cost-benefit frameworks may under-fund the integrated, catchment-wide approaches needed for full impact.

The evidence

Biggest unknown: Whether £1.5bn is sufficient to deliver at the scale needed, given that existing government NbS plans were already assessed as 'at severe risk of failure' without adequate budgets for delivery bodies.

Our reading: This policy combines a concrete funding commitment (£1.5bn to DEFRA, the EA, and Natural England) with specific environmental mechanisms: river restoration, nature-based flood management, storm overflow reduction, and soil health monitoring. Each mechanism is backed by credible evidence of real-world environmental benefit. The EA has been demonstrably underfunded against growing responsibilities, so restoring its capacity is a precondition for any meaningful enforcement or delivery improvement. River restoration and NbS flood management are well-evidenced for improving water quality and biodiversity, and the long-run cost-benefit ratios for NFM are strongly positive (£10 return per £1 invested over 30 years). Soil monitoring addresses a £1.2bn annual degradation cost and supports carbon storage and biodiversity alongside agricultural resilience. The main constraints are timing (NbS typically take years to deliver benefits — woodland planting matures over decades), and the risk flagged by the House of Lords that without adequate institutional capacity, ambitious NbS plans fail in delivery. There is also a genuine caveat that for some storm overflow targets, NbS alone may be insufficient and hybrid grey/green approaches may be needed. Absent this policy, the status quo of underfunded regulators and continued river and soil degradation would persist. The policy's funded, specific mechanisms — rather than aspirational language — earn more than a negligible rating. Near-term gains would be modest (regulatory capacity, early monitoring), but long-term effects on water quality, biodiversity, and climate resilience are material. Overall direction is improves, with moderate magnitude and long-term time horizon, at moderate confidence given delivery risks.