I was planning to write about this, but now the discussion already reached Norway; where Norwegian scientists points out that a gouvernment advisor who did'nt speak up about such reasearch should be fired. Anyways, now I have to push my post. Like the Norwegians say: "Ja, ja."
Now, I don't have complete faith in this ranking; for instance it does'nt divide between methods of 'getting high'. An easy example is the difference between smoking your tobacco and using nicotine patches or gum. I have never seen anyone get in 'real' trouble from sniffing amphetamines - and I've never seen anyone walking unscathed away from shooting it.
With that said scientists Ole Røgeberg (with the Frisch center) and Hans Olav Melberg with the University of Oslo and Sirus (Norwegian Insitute of Alcohol and Drug Research) has a good summation of some of the most important de-criminalization arguments in todays Dagbladet. I'm not going to go through their article - you can check it out if you're still in doubt. I will, though, quote the now unemployed Dr. Nutt who calls the practice of jailing people for cannabis use "infantile and embarrasing".