Jung et al. (2020) describe a method to map the IUCN habitats classification scheme directly for most terrestrial and inland water habitats. Following a decision tree approach, they intersected data on land cover (Copernicus land-cover product), climate, land use and other ancillary data source, thereby allocating each grid cell to an IUCN habitat class.

You can find the 2015 global habitat map made available as an interactive map here. Also, the Google Earth Engine code to recreate the map is available at https://github.com/Martin-Jung/Habitatmapping.

Jung, M., Dahal, P.R., Butchart, S.H.M. et al. A global map of terrestrial habitat types. Sci Data7, 256 (2020). https://doi.org/10.1038/s41597-020-00599-8