Do we need to refine our yardsticks for carbon comparisons to make them more relatable?

When environmentalists tell us a reservoir holds “enough water to fill 400 Olympic swimming pools,” we instantly grasp the scale. When a development spans “50 football pitches,” we can visualise it. These comparisons work because they translate abstract numbers into mental images the average person can relate to. Yet when it comes to carbon emissions, the metric driving every net-zero policy decision, have we failed to create similarly powerful reference points by talking about carbon savings per tonnes moved?  Does the voting public really relate to a tonne moved?

This matters enormously. Take Scotland as an example. ‘Tackling the Climate Emergency’ is one of the four primary Governmental objectives under which all other policies are measured and sit. Consider this: one 44-tonne HGV travelling one mile emits roughly the same CO₂ as six average cars covering the same distance. Every mile a HGV travels produces the carbon equivalent of six miles in the average (non EV) family car. For those already switched to an EV, clearly the carbon impact comparison is considerably greater.

Now scale that up. A typical Scottish intermodal rail freight service runs between Daventry and Mossend, a 660-mile return journey. Just one such service, carrying the equivalent of twenty HGVs – and its often more than that, prevents emissions equal to 89,000 car miles. That’s twelve years of average UK motorist driving, eliminated in a single round trip. And these trains operate five to six days per week, every week of the year.

The mathematics (and benefits) quickly scale. Twenty HGVs making that journey five days a week generate annual emissions equivalent to roughly 2.3 million car miles. One established freight service, running reliably, delivering that saving, year on year.

Our industry regularly cites that rail freight delivers approximately 75% less CO₂ per tonne moved than road freight, and in a recent presentation, Freightliner quoted the even more impressive figure of 95% if that tonnage is electrically hauled. While a great statistic, evidence suggests it perhaps needs a leg-up to really grab policymakers’ attention and action.

Grants and policy choices

Scotland’s recent policy choices serve to confirm this. The Mode Shift Revenue Support Grant, which helps companies move freight from road to rail, has been cut from £700,000 to zero in each of the last three budgets. Freight Facility Grants have been sporadic, just £5.8 million total from 2020-26, and £4m of that as a one off in 2025/26 with no funding confirmed again in the 2026/27 budget.

• Incentives to encourage rail freight operators to use electric traction?
• Incentives to encourage rail freight services to be established on highly congested road routes?
• Any consideration of the benefits using rail freight might bring to the Government regarding maintaining our crumbling road infrastructure?

Meanwhile, active travel received approximately £600 million over the same three-budget period, alongside substantial private EV incentives.

To be clear: There are clear long-term health and wellbeing benefits to supporting cycling infrastructure which satisfy other Government priorities, and EV adoption must be part of the decarbonisation solution, however legislation and vehicle manufacturer incentives influencing the marketing of what you can buy are doing much of that heavy lifting. And the evidence of real, tangible, quantifiable impact of that spend is much harder to find than that from rail freight grants given their basis in actual traffics and investments supported.

But here’s the uncomfortable comparison. Converting one daily freight service from twenty HGVs to rail delivers annual carbon savings roughly equivalent to persuading 3,300 average drivers to abandon their cars entirely, whether switching to cycling, busses or trains. And if they are cycling, the freight train keeps running whether it’s raining, snowing, or dark at 4pm in January when any sane person could be forgiven for returning to the comfort and convenience of four wheels.

This isn’t about pitting one good policy against another. It’s about understanding what moves the needle toward net zero. We need our “Olympic swimming pool moments” for carbon; comparisons that make policymakers see where the real opportunities lie.

With roughly 9,000 HGVs crossing the Scottish border daily, and 70-80% of Scottish rail freight being cross-border traffic, the opportunity for decarbonisation is substantial. Maybe it’s time to develop and use these more relatable ‘mental models’ that make the case for rail freight at scale. Else risk Governments will continue making earnest policy choices that feel virtuous but deliver marginal results, whilst the structural changes offering transformational impact go unseen, misunderstood and unfunded.

The maths is clear. We just need better ways to see it, and in an election year in Scotland at least, the political will to act on what the numbers tell us.

By Martin Bignell, RFG’s North of England and Scotland Representative.