Since its creation in 1906, Lake Carnegie has had a reputation as a place for winter skating. But in recent years, the lake has witnessed infrequent freezes, precluding skating or other winter sports, like hockey.

“The freeze proportion has decreased pretty alarmingly in the past several years,” said Grace Liu, a sophomore and computer science major. “Within a matter of decades, the probability of safe ice skating on Lake Carnegie has dropped from 1 to 0.2.”

Liu wanted to see whether this infrequent freezing on the lake might be part of a larger trend linked to global warming.

Working with her advisors, including geosciences professor Gabriel Vecchi, Liu used past media accounts and interviews to create a timeline of the years when skating was allowed on the lake.

She discovered that since 1950 the chance of the lake supporting ice thick enough for skating has plummeted dramatically. This trend was even more dramatic since 2000, when the chance of ice freezing sufficiently for skating dropped by more than half. These data match the trend observed at other lakes globally.

“When people see how climate change affects their activities and what they like to do for fun, it can send the message that it actually affects us personally,” Liu said.