The IETA  (International Emissions Trading Association) have issued this useful presentation on the consequences of the change in treatment of emissions and instruments under the ETS in terms of MiFID II

The presentation briefly looks at both the implications, of being brought into the entirety of MiFID, which will apply to some,  and also on the implications that apply to everyone, such as the fact that all such trades are now brought into EMIR. This in itself has created a great deal of work for many.