We are holding workshops to share and advance best practices in data assimilation, machine learning, and Earth system modeling. Generous support by Charles Trimble and the Heising-Simons Foundation kick-started a series of workshops in 2017 and 2018 on Nucleating a New Generation of Earth System Models. These workshops had the goal of identifying how advances in the computational and data sciences paired with the wealth of Earth observations that are now available can lead to a transformation in Earth system modeling. The Climate Modeling Alliance grew out of these initial workshops, and it continues to engage with the science and engineering community through regular workshops.