The overriding climate goal of the European Union is to achieve 20% less greenhouse gasemissions by 2020, with a subsidiary goal of saving 20% of the energy consumption.Transport will have to provide its share of these cuts. This paper starts by presenting theoverall trends regarding energy consumption in total and transport in particular. The specificsof all transport modes are addressed, and so is an investigation regarding what previously hasbeen done to calculate and compare the carbon footprint for each of them. A main challenge isrelated to how to compare solutions which transports both freight and passengers with purefreight or passenger carriers. RoPax is considered to be the most challenging of these types ofcarriers since they transport both freight and cargo. A methodology for how to deal with allcombined carriers based upon the approach which we suggest for the RoPax vessels isdescribed. Finally, the results are used to present the challenges for the RoPax-s regardingrequired energy efficiency improvements required to meet EU goals.