How Aon automated its carbon footprint measurement

The global professional services firm opted for software over spreadsheets for its carbon accounting

houses next to solar panels


Aon is a global professional services firm that exists to shape decisions for the better to protect and enrich the lives of people around the world. The firm helps clients assess and address risks associated with ESG issues, such as the impact of climate on reinsurance portfolios. Sustainability is embedded in its strategy, and the firm considers reducing its own corporate footprint to be a top priority.

"The risk of impact from climate to our global economy and society is massive and rapidly growing, which is driving one of the largest reallocations of capital in history to spur innovation, protect communities, and reduce risk.”
-Greg Case, CEO of Aon

In early 2021, Aon committed to net-zero emissions by 2030 to reduce the firm’s carbon footprint and help mitigate significant climate impacts. We spoke with Abby Neary, head of sustainability at Aon, to get her perspective on building a sustainability program and why integrating Watershed recently was a critical part of Aon’s journey.

Challenge: Increasing requests for climate data

Like many companies, Aon has seen an increase in requests for its climate data and future strategy—from regulatory bodies, current & potential clients, and employees.

“In the first half of 2023 alone, we've seen a doubling in the number of client inquiries about our climate data,” Neary said. “Other companies are making commitments and want to learn from our approach and ensure we’re aligned with their efforts.”

Neary knew that a meaningful action plan started with an up-to-date carbon footprint. But the existing greenhouse gas accounting process presented opportunities for enhancement.

Solution: Use Watershed to build a comprehensive footprint

Aon began working with Watershed in late 2022 to define its 2022 footprint and enable additional scaling of its sustainability program. In particular, through Watershed, Neary was able to achieve:

One of the primary differentiators we saw with Watershed was the capability to get more detailed with our Scope 3 emissions – enabling us to further focus our net-zero plans.

Abby Neary

Neary continued: "In addition to modeling out the emissions, Watershed has a data library of over 60,000 emissions factors and automatically pulls available vendor emissions data from CDP, which eliminates much of the manual work we were doing.”

Insights: A clear view into what’s driving emissions

Now, with a detailed footprint in Watershed, Neary is planning to bucket emissions reduction actions into three different categories:

Neary shared: "We're constantly focused on all three of those buckets, because if you just focus on any single one of them, you’re going to miss some opportunity either today or in the future to make critical reductions.”

Result: A differentiated business

As she looks to the future, Neary sees Aon’s focus on net zero as a real differentiator:

“Companies that are evaluating risk management services and that have their own net zero commitments are going to need to consider the carbon consequences of each vendor option and determine who’s paying for the cost of that carbon.

Because Aon has a concrete plan to get to net zero, the cost of doing business with us is inherently going to be less than somebody with a longer-term or no net zero goal.”
-Abby Neary

The last word on why climate action matters

According to Neary, there are two key reasons why corporate leaders should be focused on creating an actionable footprint:

"Number one is regulation—it’s becoming increasingly mandated and companies should plan for that. Number two is that there is a real hard dollar return on investment from reducing emissions that we see in our work.”
-Abby Neary

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