Few people understand the human dimension at the heart of climate policy as well as Wei Peng.
An assistant professor at Princeton's School of Public and International Affairs and the Andlinger Center for Energy and the Environment, Peng has long brought an engineering focus to her climate policy research. She once viewed technology as the primary solution for regions struggling with energy transitions. Today, she considers that approach overly simplified. Around 2016, when she was finishing her doctorate at SPIA and the Trump administration began rolling back U.S. federal climate policies and regulations, she realized that her computational models, which analyze an energy system's transition from fossil fuels to renewable energy sources, must better account for the human element — the behavioral, political, and institutional factors that often mark the biggest difference between a theoretical model and the real world.
"The fact that something is theoretically optimal doesn't mean that it is actually politically or economically feasible to get implemented in the real world," she said. "We need to make the model world closer to the real world. What we try to do is to improve the institutional and behavioral realism of the models so that hopefully the results will be more useful to the real-world decision makers."
In her modeling work, Peng is mindful that a society's path toward energy transition can create both desirable unexpected benefits and unexpected harms. Sometimes taking action to cut carbon creates a positive synergy: Switching from coal to solar, for example, reduces CO2 emissions and air pollution, slowing global warming and making the air healthier to breathe. But decarbonization is rarely that straightforward. Her models reveal how some strategies — certain forms of bioenergy, for instance — can increase particulate pollution or create land-use pressures that harm public health and livelihoods.
"When you're thinking about very specific energy strategies, there might be serious tradeoffs that policymakers need to consider," said Peng, whose influence on policy debates across the globe includes being a co‑author of the Fifth National Climate Assessment, the U.S. government’s preeminent report on climate change impacts, risks, and responses.
From Peng's perspective, achieving net-zero carbon emissions, which would significantly slow climate change, is no longer primarily a technological problem. Instead, she views it as one goal competing with many priorities dependent on local conditions. Peng understands this personally. Having grown up in China, she retains memories of her extended family who struggled in poverty before economic reforms led to rapid growth. She recognizes that, while urgent and existential, the problem of climate change can feel utterly remote to a person who is still struggling to make their ends meet.
"For some people in the climate world, they may feel that climate is the only thing that we should be caring about," she said. "I disagree with it, though I see where it comes from. I wouldn't have devoted my profession to climate policy research if I didn't think it was important, but at the same time, I realize that, to many people and to many countries, it's a lot more complicated. We really need to be thinking about climate and energy transition in a way that is aligned with more urgent, local priorities and a location’s development stage."
Real-world context is also central to what Peng brings to her students. Her climate and health course incorporates real-world case studies from Latin America, Africa, and Southeast Asia to show students how decarbonization has already improved — or could improve — human health in overlooked places. Beyond the classroom, Peng mentors a deliberately interdisciplinary group of graduate students, postdocs, and undergraduates from policy and engineering backgrounds. In the coming months, her group will start partnering with New Jersey's Department of Environmental Protection to build state-specific modeling capacity that may be used to influence actual policy decisions.
"I really enjoy seeing the students learning from each other and challenging each other," said Peng, who, after working on climate change policy for so many years, still feels hopeful — despite seeing administrations come and go, commitments secured and rolled back, and political attention ebbs and flows.
"I'm still optimistic because I think energy transition is going to continue in the direction that we have been seeing over the past decade — more renewables and more electrification, because that's just abetter world, a better way of using and managing energy," she said. "Simply put, people like better, cleaner and cheaper technology, and a lot of low-carbon technologies are indeed getting better, cleaner and cheaper all the time."
Wei Peng during her appearance on PBS Energy Switch.
Photo courtesy of Energy Switch/PBS