Global climate models are software behemoths, often containing more than a million lines of code. Inevitably, such complex models will contain mistakes, or "bugs." But because model outputs are widely used to inform climate policy, it's important that they generate trustworthy results. Ulrike Proske and Lieke Melsen set out to understand how climate modelers think about, identify, and address bugs. They interviewed 11 scientists and scientific programmers from the Max-Planck-Institut für Meteorologie who work on the ICON climate model for their study published in Earth's Future. When new code is developed for ICON, it's screened and tested to catch bugs...