Advancing carbon transparency in digital out-of-home with Broadsign and Scope3

March 10, 2025Liseanne Gillham

The out-of-home (OOH) advertising industry is undergoing a major transformation, with companies across the sector working to reduce the environmental impacts of advertising. As more brands and agencies set ambitious corporate carbon reduction goals this year, businesses need reliable carbon measurement data to track and minimize marketing’s impact on their footprint.

With programmatic display advertising alone generating 3.8 million metric tons of CO2 emissions globally each year, the pressure is on to find lower-impact alternatives. And the advertising industry is already responding— two-thirds of Fortune 500 companies have set significant climate commitments, with many aiming for net-zero emissions by 2030.

At Broadsign, our commitment to tracking, improving, and offsetting our own carbon footprint is constant, and our latest partnership with Scope3 builds on this belief. Together, we’re working to make it easy for brands and agencies to plan and buy OOH media with carbon impact in mind. At the same time, we’re focused on enhancing carbon reporting for the OOH industry. 

Partnering for a greener future in OOH 

Scope3, a leader in carbon measurement for advertising, provides comprehensive emissions data across multiple media channels with the mission to decarbonize media and advertising. However, up until recently, its platform didn’t include a large amount of data from DOOH. We teamed up with them to bring more DOOH carbon measurement data to the platform, so media buyers and owners can make more informed, sustainable decisions while advancing carbon transparency and reduction efforts.

With Scope3’s DOOH carbon measurement data now accessible to brands and agencies, they can easily factor DOOH’s environmental impact into their omnichannel media plans. Our collective efforts have enabled DOOH property and format emissions data for over 1 million screens globally on the platform, providing media planners with more comprehensive carbon impact data across their media channels like social, CTV, and digital online. 

For media owners, Scope3’s data helps position DOOH as a low-carbon media choice, provides carbon impact reporting to advertisers, and demonstrates its role in reducing emissions across omnichannel campaigns. Additionally, DOOH media owners can contribute inventory data to refine Scope3’s emissions model for more precise reporting.

Broadsign’s first partnership with a carbon measurement platform also sets the stage for future innovations, like dynamic campaign planning based on carbon footprint. We’ve been aware of Scope3 for some time, but our initial focus was on addressing our carbon footprint and achieving carbon neutrality internally. Once that plan was in place, we shifted our attention to supporting the OOH industry. Given that Scope3 is the industry standard for advertising carbon measurement, partnering with them to help launch the DOOH channel and provide additional insights for their modelling was a natural next step.

DOOH: A carbon-efficient advertising channel

Through our contributions to  Scope3’s model, Broadsign is helping to improve carbon measurement and transparency, giving media buyers more accurate sustainability insights. As brands and agencies prioritize sustainability, data collected to date highlights the benefits of including DOOH in a media mix, reinforcing its position as one of the most carbon-efficient advertising formats. 

Compared to other digital channels, DOOH generates significantly lower emissions, standing out as the greener advertising format on a per-impression basis. Web-based ads produce 3.7 times more gCO2 per impression than DOOH, while CTV generates 14.7 times more—and that figure doesn’t account for the impact of personal devices like mobile phones and laptops. 

Under the Scope3 measurement model, DOOH’s carbon footprint mainly comes from the electricity used to power screens, with factors like operating hours, brightness settings, and the local energy grid all playing a role. For example, running screens 24/7 uses more energy, brighter displays require more power, and fossil fuel-based grids lead to higher emissions. That said, DOOH remains highly efficient, thanks to its ability to reach large audiences in high-traffic areas. By delivering impressions at scale, its emissions are more impactful in terms of business outcomes while remaining lower than other digital advertising formats.

This graph illustrates the grams of carbon emitted per thousand impressions across all channels measured by Scope3. In countries with available DOOH benchmarks, the channel stands out as a significantly lower-emission option than others.

For brands and advertisers looking to reduce their carbon footprint, choosing high-quality, low-emission screens is a great place to start. Optimizing campaign timing can also help—certain hours may align with a cleaner energy grid mix or higher foot traffic, making ads more effective and sustainable. Even a small shift toward DOOH can make a big impact while keeping omnichannel campaigns effective and engaging. Plus, incorporating DOOH into a broader media mix enhances the performance of other channels, making it a win-win for sustainability and strategy. 

With benchmark data now available from Scope3, media owners also benefit. They can create carbon intensity reports to highlight DOOH’s sustainability advantage. Looking ahead, we anticipate more sustainability-focused media owners will use this data to strengthen how they position DOOH’s impact in the larger omnichannel ecosystem, and illustrate how the medium can help offset the carbon footprint of more energy-intensive channels like CTV, video, and web. 

As the industry evolves, Broadsign’s dedication to driving both our own sustainability initiatives and supporting the advertising industry is unwavering. We will continue to equip our team and partners with the transparency and insights needed to make more informed, responsible decisions.

Liseanne Gillham
Liseanne Gillham

VP Marketing