What achievements are you most proud of from your time leading federal sustainability efforts?

Andrew Mayock: I think our biggest accomplishment was proving we could put the federal government on track to meet ambitious climate goals. President Biden set targets to significantly reduce U.S. government emissions by 2030, and by 2024, we had already achieved a 40% reduction. We demonstrated that the government could make real progress on electrifying buildings, transitioning to clean vehicles, and powering operations with clean energy. We were showing that these weren't just aspirational targets — they were achievable with the right commitment.

What do you hope your sustainability legacy will be?

Andrew Mayock: During our four years, we proved that meaningful progress was possible. While many corporations and organizations made big promises but struggled to deliver, President Biden both made ambitious commitments and achieved significant results to back them up. When President Biden took office, there were fewer than 2,000 zero-emission vehicles across the entire federal fleet of 650,000. By the end of our term, we had 90,000 either in use or on order. Similarly, we went from having barely a thousand charging stations to 60,000 in development with 10,000 actually installed and functioning.

That scale of transformation is comparable to Amazon's partnership with Rivian. They set a goal of 100,000 electric delivery vehicles by 2030, and currently have tens of thousands on the road. The federal government was working at that same ambitious scale, just with less public recognition. This demonstrates our real legacy: we proved that the government can make big promises and actually deliver on them.

How did you use the government's purchasing power to support decarbonization in other areas?

Andrew Mayock: The federal government is a major purchaser of construction materials in the United States. We launched the Buy Clean program using funds from the Inflation Reduction Act, and funneled $1.2 billion through the General Services Administration, which handles a substantial amount of federal construction work across the country.

We leveraged this incredible buying power to signal to the market that we wanted materials with lower climate impact. What we discovered was encouraging — suppliers could deliver a 30% emissions reduction using existing technologies without any dramatic innovations.

We also created opportunities for truly innovative startups. For example, we helped companies developing zero-carbon concrete get their products into government construction projects. This gave these small companies their first major customers and a foothold in the market as they scaled their businesses. We did the same with other technologies, like advanced window systems from a Colorado company that dramatically improve building efficiency.

How are you responding to the current administration's different approach to climate priorities?

Andrew Mayock: I think the changes we're seeing were expected based on campaign promises. That said, it's disappointing to see progress stall, particularly around making government operations more efficient and resilient. Many of our initiatives were fundamentally about smart governance — reducing long-term costs while making federal facilities better prepared for climate impacts. Those improvements benefit everyone regardless of politics, so seeing that work halted is unfortunate.

Are there any areas of energy policy where you see potential for continuity despite the change in administration?

Andrew Mayock: Energy security is an imperative that transcends administrations. I'm seeing continued support for nuclear energy, where the Biden Administration made significant progress shifting public perception and advancing new technologies. Geothermal energy is another bright spot — we established geothermal systems at several defense installations that are likely to remain priorities. Even in areas where progress might slow, like solar and wind development, the economic fundamentals are so compelling that I believe they'll continue to grow despite policy shifts.

What do you see as the biggest challenge for scaling climate technologies?

Andrew Mayock: The fundamental challenge is creating market certainty. Climate technologies often require longer development timelines and more capital than software, so investors and entrepreneurs need confidence that policies supporting these innovations will remain stable. The tax credits and other mechanisms established in recent legislation provide that 10-year window of predictability, which is crucial. If those frameworks remain largely intact, I believe we'll see this ecosystem of climate innovation continue to flourish throughout this decade, helping us compete globally while addressing climate challenges.

What's next for you?

Andrew Mayock: I'm excited to become the inaugural vice chancellor of sustainability at the University of Colorado Boulder. Universities are uniquely positioned at the intersection of research, education, and real-world implementation. Boulder in particular has an incredible ecosystem where cutting-edge climate research can connect directly with entrepreneurs who take those innovations to market. The university has built a strong foundation over decades, and I look forward to helping expand and accelerate that work — for example, bringing together researchers, students, and the local startup community to develop and scale solutions that make a meaningful difference on climate and sustainability.