Sustainability & carbon in DOOH

Sustainability is now a buying criterion, and DOOH sits in an awkward spot: digital screens are always-on and visibly power-hungry, yet out-of-home is one-to-many — one screen, many viewers — which should make its per-impression footprint low. So which is it? This analysis sorts the credible measurement infrastructure from the vendor-modelled numbers, and lands on an honest position: per-screen power is real and measurable; per-impression carbon is favourable but the industry “marks its own homework.”

Key findings

Real measurement infrastructure now exists — the Global Media Sustainability Framework (Ad Net Zero) and Scope3’s DOOH model, with buyable “green” deals (Ad Net Zero, Scope3 — primary).
The hard end is screen power: a large digital billboard can draw on the order of ~40,000 kWh/yr (planning filing — directional/primary).
The soft end is per-impression carbon — it depends on an estimated audience multiplier and is produced only by self-interested parties (Scope3 method — primary; figures — directional).
DOOH-vs-other-media efficiency claims (e.g. 20–30× better than display/video) all come from OOH vendors — the direction is plausible, the multiples are marketing (VIOOH — directional).
Regulation is tightening on screen energy — overnight switch-offs, display efficiency standards (France, EU — primary/directional).

The real infrastructure: standards and green deals

The encouraging news is that DOOH sustainability is no longer pure hand-waving — there’s genuine measurement infrastructure:

The Global Media Sustainability Framework (GMSF), run by Ad Net Zero, gives the industry a shared methodology across channels, splitting OOH into classic/transient/digital. It was built because 30+ rival methodologies existed before it (Ad Net Zero — primary). One important caveat: GMSF versions are not back-comparable, so any “emissions fell X%” claim spanning a version change is invalid.
Scope3 added DOOH to its carbon model and powers buyable “green curated deals” (launched via Perion/Hivestack in 2024) and a screen-data partnership with Broadsign — so a buyer can transact a lower-carbon DOOH deal as a deal ID (Scope3, Perion, Broadsign — primary that the products exist).

These are real, and they matter: the channel now has a common language for carbon and a way to act on it. What they don’t yet provide is an independently audited number.

The hard end: screen power is measurable

The most defensible data is absolute screen energy, because it’s metered. Planning filings put a large digital billboard at on the order of ~40,000 kWh/year — comparable to roughly a dozen households — with smaller digital units proportionally lower (JCDecaux/Daktronics planning filing, via an advocacy group — directional/primary; trust the metered number, not the framing). Industry-commissioned analysis frames OOH as a small slice of advertising’s footprint — around 3.3% of UK advertising’s power and under 3.5% of its carbon (KPMG, commissioned by Outsmart — directional; ratios only, self-reported operator data). That’s credible on direction but is an industry-commissioned ratio, not an absolute audited total — and “small share of ad spend → small share of energy” is partly a denominator effect.

So: a screen’s power draw is real, non-trivial, and measurable. The always-on critique isn’t wrong — a digital screen uses meaningfully more energy than a printed poster.

The soft end: per-impression carbon

This is where to be sceptical. The case for DOOH’s footprint is per-impression: one screen shared by many viewers should beat a per-device channel like CTV or display. The numbers that express this — e.g. DOOH at ~0.04 gCO₂e per impression vs ~0.84 for display and ~1.24 for video, i.e. “20–30× more efficient” — come entirely from OOH-selling vendors measuring themselves against comparators they don’t control, with no independent auditor (VIOOH — directional). And the mechanism reveals the catch: per-impression carbon is a ratio whose denominator is an estimated audience multiplier; when a screen lacks data, the model uses a generous default (e.g. the 80th percentile of comparable screens) (Scope3 method — primary). A more generous assumed audience mechanically lowers per-impression carbon. So:

The one-to-many advantage is physically plausible — but the specific multiples are vendor-modelled artifacts, not independently audited facts. No independent per-impression DOOH carbon figure exists.

The honest line to hold: per-play screen energy is measurable; per-impression carbon depends on an estimated audience multiplier and is currently produced only by self-interested parties — directionally favourable to DOOH, not independently verified.

Regulation is tightening on energy

The pressure that’s most concrete isn’t about carbon accounting — it’s about screen power directly:

Overnight switch-offs. France requires illuminated ads off roughly 01:00–06:00 (digital may show fixed images only), with fines, in force since late 2022 (France — primary/directional).
Display efficiency standards. The EU’s Ecodesign rules for electronic displays set energy-efficiency limits tied to size and luminance; professional signage is treated separately, but the direction is toward stricter panel efficiency (EU — primary regulation; exact thresholds directional).

For an operator, this makes energy management — scheduling, brightness control, efficient panels — an operational and compliance issue, not just an ESG talking point.

The honest position for beauty

Where does this leave a beauty network or advertiser? Claim what’s defensible and flag what isn’t:

Use the real infrastructure — GMSF methodology and Scope3-powered green deals are legitimate ways to measure and act, and worth adopting.
Be honest about per-impression claims — cite the mechanism (shared screen, one-to-many) confidently; attach a “vendor-reported, not independently audited” flag to any specific multiple.
Manage screen energy — scheduling and brightness aren’t only cost levers, they’re the part regulators are actually tightening.
Don’t greenwash a salon screen — an in-venue beauty screen is small-format and indoor (far below a roadside spectacular), but it’s still a powered device; the credible story is “measured and managed,” not “carbon-free.”

Sustainability in DOOH is a real, maturing discipline with genuine standards — and a field where the headline numbers still come from the people selling the screens. Cite the standards confidently, the numbers carefully.

Methodology & caveats

Verified (primary): the Global Media Sustainability Framework (Ad Net Zero) as a real cross-channel methodology (and its non-back-comparable versioning); Scope3’s DOOH carbon model, the green curated deals (Perion/Hivestack, 2024) and Broadsign screen-data partnership existing as products; the Scope3 per-impression method using an estimated audience multiplier with an 80th-percentile default; EU Ecodesign display rules and France’s overnight illuminated-ad switch-off as real regulation. Directional (vendor / industry-commissioned — not independently audited): the ~40,000 kWh/yr large-billboard figure (planning filing, presented by an advocacy group); OOH at ~3.3% of UK ad power / under 3.5% of carbon (KPMG, commissioned by Outsmart — ratios, self-reported); the per-impression efficiency multiples (~0.04 vs 0.84 vs 1.24 gCO₂e; “20–30×”) from VIOOH and similar OOH-vendor sources measuring themselves. Not asserted — none exists: any independent, peer-reviewed per-impression DOOH carbon figure; an OAAA carbon program; AdGreen covering DOOH delivery (it governs production); absolute audited OOH energy/carbon totals. Cite the standards and mechanisms; flag every specific number as vendor-reported.