For more than 30 years, David Harwood, professor in the Department of Earth and Atmospheric Sciences at the University of Nebraska-Lincoln, has been a leading scientist investigating how global temperature change affected Antarctic ecosystems and the stability of the large southern ice sheets over millions of years in the ancient past. He and other Nebraska scientists, engineers, drillers and students have helped lead international efforts using drills to retrieve water samples, ice and sediment cores to understand Antarctica's past climate and what it portends for the future as the world warms in the coming decades. In this Q&A, he discusses his work in light of the recent United Nations' Conference of the Parties (COP26) in Glasgow on climate change. Opinions expressed in the following Q&A are Harwood's own.