Yes. As a sixteen year-old, cannabis usage is dangerous. This is not to scare you. I am not against marijuana, personally.
The most recent technology has demonstrated that people who smoke weed before they're around age eighteen are more likely to develop schizophrenia, or mental disorders with psychotic components. Though smoking marijuana hasn't been shown to cause schizophrenia by itself, people your age with certain genetics and life experiences who smoke are likely to develop the disease. This means you may or may not be at risk. The only way to know is to find out; you don't want to do that, do you?
Please review the current literature. I know you may not know how to evaluate a study, but each one I've come across, as well as every psychiatrist I've met, has been of the same opinion.
http://www.sciencedirect.com/science/article/pii/S0022395612003512
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055821
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3544398/
http://www.sciencedirect.com/science/article/pii/S1876201813000944
I wish it wasn't so.
I don't want to tell you what to do because I believe in freedom of choice at your age. Also, I started smoking weed at age fourteen. I wish I hadn't, though. I believe it has contributed a fair amount to my current psychiatric illness. I don't have schizophrenia, but i experience psychotic symptoms.
If you choose to smoke:
1: you may view it as the worst choice you ever made
2: don't say you weren't warned (I wasn't, though I don't know how much a difference that would've made)
If you experience any of these symptoms while high, for god's sake, don't do it again:
1. hearing things, seeing things, or otherwise sensing things which aren't there
2. extreme anxiety
3. extreme paranoia
4. deep depression
5. unexplained hopelessness
6. phobia (avoiding something for no reason, like closing the window because it makes you feel more safe)
7. panic attacks/trouble breathing/tremors (physical shaking)
8. irrational anger or aggressive actions
9. crying
10. a general, very uncomfortable feeling of being mentally confined
If you have a bad experience after smoking weed, or experience any of the effects described above, you'll know that it is definitely not a good idea to use. The most unhealthy thing you can do if this happens is (of course) continue to take marijuana, worse, continue to take marijuana along with another drug to make the symptoms not appear again; your brain will still be negatively affected, you just won't know it.
I want to be clear on something else: you do not necessarily have to have these symptoms to develop a later mental illness.
You'll find a lot of people on this site still use the drug despite having psychotic reactions. One of them was me. I finally quit. Its quite sad.
I'll bet that your friends think the drug is harmless, too. I know my friends did. For some, its about as damaging as drinking a cup of green tea. For others, you might as well give them a high dose of pcp, methamphetamine, and lsd at the same time then throw them in a war zone (it can be extremely damaging, as i've said over and over; i just want to make sure you understand).
If you continue to smoke (assuming you don't have an obviously negative reaction), these would be my guidelines:
-watch out for these symptoms in yourself and others
-stay busy while you're high
-don't smoke more than once every two days
-don't smoke in areas you're uncomfortable with
-don't smoke if you have a curious sensation that you don't want to smoke, even if part of you wants to
-don't smoke synthetic cannabinoids, or legal substitutes
-don't let anyone pressure you into smoking more than you're 100% comfortable with
I'm sure others have productive suggestions to add. Any questions?