Next to the Copernicus Climate Change Service (C3S) CDS toolbox for online access, there is another option for land cover data: the ESA CCI land cover tool available at the following link http://maps.elie.ucl.ac.be/CCI/viewer/ .
On a more general note, there is also the popular Geospatial Data Abstraction Library or GDAL, with an utility called gdal_translate, that is able to read and write many file formats. Recent versions have good support for reading netCDF and are integrated into nearly all open source geospatial and GIS tools, notably QGIS (menu Raster). Moreover, some GDAL options are available in ArcPy too, see the following link for details: https://www.arcgis.com/home/item.html?id=bbe841db0b144578a05d85735010596e
