I think it is naive to believe that there will not be an increase in use if it were legalized. Sure, the legality may not dissuade some users, but there is a percentage of people who are dissuaded by it. In my opinion it is also naive to think that it is not a habit forming drug.
I think there may be a slight rise, but I think it is very unlikely that there would be a rise big enough to warrant concern. Figures also might reflect 'more' people smoking pot, but this could also just mean that once it's legalised, people won't feel they have to lie about using it. Like I said - large percentages already use it, the people who are most likely to, or who want to, have easy access to it - the only thing that is likely to significantly change with legalisation is that the number of arrests will go down.
Yes, by eating it, many of the harmful effects of smoking it might not occur, but the reality is that the majority of users DO smoke it. And they are likely to continue to do so. By smoking it, they are not only harming themselves, but also opening up the general public to whole new kind of second hand smoke.
It's true, the majority smoke it and will probably continue to do so. However, until a law is passed that bans all forms of smoking, we can't allow tobacco smoke, and then turn around and say marijuana smoke would be far too unhealthy. Tobacco smoke is in fact more dangerous, so that would make no sense. Many countries now ban public smoking, so most recreational marijuana use, which already takes place behind closed doors, is unlikely to suddenly move out onto the streets.
Furthermore, you claim that it has limited negative effects. Studies have shown that the potency of marijuana being cultivated now is on the rise. What is available now, is way more potent (% of THC) than that which was available several years ago. It can be argued that as the potency continues to increase, so too will the negative side effects of long term use. We cannot assume that filling out body with chemicals of any nature would not affect and change the way in which our body functions, especially over the long term.
Actually, this isn't true. Although it is now a popular myth to bring up in the media, especially as a scare tactic, research into the 'studies' that claim marijuana is worse now than say 50 years ago have been shown to be skewing the figures by using the lowest THC counts from previous years, and comparing them to the highest THC counts in recent times. Obviously this provides a far larger disparity, and makes for better headlines, whereas the truth is most people won't be smoking anything much different from what their parents and grandparents were.
I have a link to back this up:
http://www.drugpolicy.org/marijuana/factsmyths/#potent
Marijuana is not as dangerous nor as likely to cause problems as anti-drugs campaigners would have everyone believe. Having it as an illegal substance only means that people tend to get arrested for possessing or growing it - there's no evidence to suggest it makes people violent or anti-social, and obviously if it were legal it should still be subject to restrictions like other drugs, such as no driving while under the influence.
