Several of M²LInES members and affiliates (Bhouri, Gentine, Zanna, Abernathey, Busecke, Mooers, Shamekh, and Yuval) have contributed to this LEAP paper presenting ClimSim, the largest-ever dataset designed for hybrid ML-physics research. It comprises multi-scale climate simulations, global in coverage, spans multiple years at high sampling frequency, and is designed such that resulting emulators are compatible with downstream coupling into operational climate simulators. The data and code are open access.