Keppel-Aleks has made many notable research contributions, especially surrounding greenhouse gas emissions and global climate change. She led several research projects, such as a project titled "Developing a Mechanistic Understanding of Variability in the Atmospheric CO2 Growth Rate Owing to Interannual Climate Oscillations", in which scientists explored how Earth systems react to a changing climate.[4] She has also participates in NASA's OCO-2 research team, in which she and 20 other scientists work to investigate how human populations interact with, and contribute to the presence of CO2 in Earth's atmosphere.[5]