Alex Hansen stepped foot in a landfill this summer for the first time to study the consequences of methane emissions. What he saw sparked a growing interest in climate change research and environmental data analysis.

Hansen, a rising senior in the Paul M. Rady Department of Mechanical Engineering, spent his summer break in CU Boulder’s Summer Program for Undergraduate Research (SPUR). 

 

Alex Hansen (right) working alongside graduate student SPUR mentor Gabriela Cortes (left) in the Hannigan Air Quality and Technology Research Lab.

The program aims to increase undergraduate research engagement and interest by pairing nearly 125 engineering students from across the college in research labs with faculty members and graduate mentors. For 10 weeks, students foster unique, hands-on research experiences—like a trip to a landfill in Los Angeles—and develop crucial skills that serve them well beyond their undergraduate journey.

For Hansen, it was a special curiosity that led him to the SPUR program. One that started from a simple conversation.

“I spoke with someone I ran into one day a while back who worked at a landfill. He was telling me how dangerous methane is and how important it is to burn off methane,” said Hansen. “I was just so fascinated by it all. When I saw the project description on the SPUR website, I knew it was something I wanted to learn more about.”

And dangerous is an understatement. Methane, one of Earth’s most potent greenhouse gases, is one of the primary contributors to climate change. Its atmospheric lifespan may be shorter than other greenhouse gases like carbon dioxide, but it can trap significantly more heat per molecule, making it extremely hazardous to human and environmental health.

According to the UN Environment Programme, methane is 80 times more potent at warming than carbon dioxide over a 20-year period. It’s also responsible for nearly 30% of global warming since pre-industrial times and is a key culprit for the formation of ground-level ozone, which causes one million premature deaths every year.

It’s a spiraling issue, but Hansen says his SPUR project titled “Characterizing Landfill Methane through a Low-Cost Ground-Based Sensor Network,”  looks to attack the crisis by addressing some of the world’s most prevalent methane emissions sites.

“Landfills are one of the largest emitters of methane in the United States,” Hansen said. “I believe waste is about third for methane emissions across the entire world. If we are able to study a landfill and learn more about the way methane spreads in the atmosphere, maybe we can find a way to make improvements to landfill infrastructure and lower emissions.”

To do this, Hansen and his lab mates in Professor Michael Hannigan’s Hannigan Air Quality and Technology Research Lab started working with a network of 24 low-cost air quality sensors called L-Pods that were deployed across a landfill in Los Angeles at the beginning of 2025. 

The L-Pods are equipped with two metal oxide sensors that collect air pollutant data and another sensor that tracks temperature and relative humidity. The data is then stored locally and transmitted to the cloud every 10 seconds for ongoing monitoring. 

These unique sensors may not be as individually powerful as the industry-grade technology used by the Environmental Protection Agency (EPA), but they are cheap and efficient. This allows the group the ability to position more sensors across a landfill than they previously could, giving them a precise methane reading that represents a much larger region.

 

Hansen showcasing the inner workings of an L-Pod air quality sensor.

Hansen spent a majority of his summer SPUR experience helping the team analyze the data gathered from the sensors. But he was able to see the sensors in action firsthand at the Los Angeles landfill where they are deployed.

It was crazy seeing how much trash we make and the operations needed to contain it all,” said Hansen. “And these low-cost sensors were awesome to see, too. We can add so many more positions and measure way more often than traditional measuring devices. It’s super exciting to see the data we collect in real-time and how impactful it is.”

Hansen’s journey through the SPUR program ended with a final presentation at the end of July. It was a chance for him to share his learning and reflect on his summer. 

In many ways, he said it was a rollercoaster ride filled with highs and lows. Some seasoned researchers might call that the typical research experience.

But Hansen also said it was valuable and fulfilling. So much so, that he might be eyeing a future career in research.

“Being in the lab was definitely a learning curve at first. Just learning the terminology and trying to get up to speed as quickly as possible was tough,” Hansen said. “But there’s so many opportunities to make a big impact in research. I’ve learned so much from amazing people this summer and I am definitely curious about pursuing research in a master’s program after graduation.”