The room was filled with round tables, each containing blank sheets of paper and several markers. We sat down at a table and introduced ourselves to our soon-to-be partners. With the opening remarks of the workshop, we looked at each other and immediately knew what the paper was for: solving Fermi problems.

The workshop was part of the Sigma Pi Sigma Physics Congress (PhysCon) held in Providence, Rhode Island, last November. During PhysCon we had the chance to engage in several events centered around the idea of how physics can be beneficial and affect the quality of human life. One of the commonalities we noticed among these experiences was a focus on climate change and how we as physicists can help mitigate the impacts. The goal of this particular workshop was to apply “physics thinking” to get to the heart of our connection to climate change.

The workshop leaders, University of Maryland professor Ellen Williams and University of Wisconsin – River Falls professor Earl Blodgett, explained that many climate change–related questions seem too broad or wide-ranging to solve easily, but with logic and sensible assumptions it’s possible to arrive at a reasonable answer. For instance: How much carbon dioxide is produced by cars every year worldwide? How much money could a household save by switching to windows that trap more heat inside?

Each table received one such Fermi problem, named after the physicist Enrico Fermi who often engaged students and colleagues with questions like, How many piano tuners are there in the city of Chicago? We were expected to work together to make reasonable assumptions in pursuit of an answer. Imagine the scene as tables of newly acquainted physics students discussed the logistics of how many cars are owned and driven in the world!

“We have understood the effect of C02 on the world for well over 100 years.”
-Ellen Williams, University of Maryland professor and former director of the Advanced Research Projects Agency – Energy, during her 2019 Physics Congress plenary.

Amid this chaos was a deeper point. Despite the complexity of climate change and how we must sometimes rely on approximations in our quest for understanding, the questions forced us to confront, as humans, our habits and how they affect the Earth. Thinking through how many people drive a car every day and how far, and then considering gas mileage, really started to put the human contribution to climate change into perspective. “It was an absolutely groovy exercise that really gives us insight into the scope of the everyday,” said Nicholas Stubblefield, a workshop participant from Boston College. If one person decided to change their routine, the impact would be minute. But what if many people shared this mentality?

We saw this topic from another angle during a PhysCon tour of the Naval Submarine Base New London in Groton, CT, the world’s first submarine base at just over 150 years old. The Naval Submarine School is one of the largest parts of the base, home to around 1,200 sailors studying to become submariners. The base has many tools to help students prepare for life on a submarine, including piloting simulations, rooms where students practice making repairs in a flooded submarine, and a 40-foot-deep pool where they practice escaping from a flooded submarine. Along with these skills, the sailors also learn how to live efficiently—on a submarine there is not much extra space for food and waste! On the tour, we also learned that the Navy has been moving submarines from diesel to nuclear power. This enables them to stay at sea longer and reduces their emissions. While this is only a small step, it is heartening to see these changes being made.

“The science is not confusing and it’s certainly not poorly understood.”
-Ellen Williams on climate change and the effect of CO2 on the Earth (2019 Physics Congress plenary).

We have taken the knowledge from our PhysCon experience and started implementing changes in our physics department. For example, we recently reinstalled a monitor on our building that tracks weather, wind speed, and temperature in real time. We are thinking about how to use this information to track environmental patterns.

There are many opportunities for action before us, and if we all implement changes, no matter how small, the impact will add up. We encourage you to challenge yourself or your chapter to invent something or change something about your lifestyle that benefits you, those around you, and our Earth. You may be surprised with the creative solutions you find. Hopefully, instead of solving Fermi problems related to how much more carbon dioxide is released into the atmosphere each year, someday we’ll be able to address problems related to how much progress we’ve made.