EY Nederland
CO2 reduced
Challenge
From promise to proof
Sustainers helps organisations turn small, practical actions into measurable CO2 and business impact. Step by step, change becomes part of how work is done.
Get in touchBy deleting 60,000 emails alone, I saved an estimated 1,400 kg of CO₂ — Sustainers made our digital footprint visible and gave us concrete steps to reduce it.
EY already had its own tool to calculate the exact CO₂ footprint of employees. Precise, personal, and serious. For employees who were already intrinsically motivated, it worked well. But the tool did not reach the broader audience. The large middle group did not engage. Not because the willingness was missing, but because a calculator does not create movement.
EY lacked scalability and an approach that also gets people moving who do not yet see sustainability as their theme. Sustainers fills exactly that gap. Not as a replacement, but as an addition. The EY tool for depth. Sustainers for support and broad behavioral change.
The approach
In November 2025, EY started a two-week pilot around two themes directly connected to daily work practice: Digital Waste and Sustainable AI, created specifically for EY.
The pilot was launched with a hybrid kick-off. 21 employees divided across two teams, with sponsors from management and two team captains who drove the competition on the work floor.
No mandatory program. A competition with a serious goal.
What happened
Engagement was high from the start. Participants logged daily check-ins, accepted challenges, and challenged each other. The biggest awareness shift emerged around digital behavior. Employees understood for the first time how much energy is involved in the way they organize their working day.
Not because they did not want to know. But because no one had ever shown it to them in a concrete way.
The winning team, the Super Green Troopers, achieved 7,183 kg CO₂. Top scorer Rens Altinga personally achieved 1,984 kg.
The results
21 participants. Two weeks. 11,952 kg CO₂ reduced and avoided.
The initial goal of 4,500 kg was more than doubled. The ambitious final goal of 12,000 kg was reached at 98%.
95% of participants remained actively involved throughout the full pilot. 213 activities were started, and 951 check-ins were logged.
Participants rated the insights gained with a 4.22 out of 5, and the applicability in daily practice with a 4 out of 5.
The estimated business value through reduced material use, lower energy costs, and productivity gains: between €2,500 and €8,000.
Based on 21 participants, in two weeks.
The learning
An existing measurement tool and Sustainers do not compete with each other. They reinforce each other.
Exact measurement and broad activation are what a sustainability program needs to grow from the frontrunners to the entire organization.
What this means
Two weeks is enough to set something in motion that lasts.
People who previously saw no connection between their digital behavior and CO₂ now saw that connection. And changed their behavior.
In the coming year, we will continue exploring how we can create impact together.