The development of EC-Earth4 was started by the EC-Earth consortium in 2020. One of the major changes is that in EC-Earth4 the atmospheric model will be based on OpenIFS instead of IFS, which will weaken the licensing restrictions and make it much easier for academic groups to use the model for their research.

The first release of EC-Earth4 was based on OpenIFS 43r3 and NEMO 4.2.

The EC-Earth 4.1.1 release is the first EC-Earth release based on OpenIFS 48r1. Further it is based on NEMO 4.2.2, XIOS 2.5+ & OASIS3-MCT 5.2. The main features and known issues are described in the EC-Earth 4.1.1 release notes. The basic configuration will have dynamic vegetation and an interactive modal aerosol scheme based on HAM-M7.