My reputation is not 1500 but i wanted to add some new tags. There are some emerging technologies which should be there in Stack Overflow.
I think you would have better luck if you compiled a list of existing questions you think the tag would apply to. Post it here on Meta along with a description of what the tag means. Then someone with enough rep could create it for you if they agreed that it was a good idea.
The fact that you don't have a high enough rep to do it yourself doesn't mean it can't be done. It just means you need to convince the community that it is a good idea. And without concrete evidence at least some things would be improved if it were added, you're not going to convince anyone.
If you don't have privileges to create tags, just add a comment on question to create a new tag for the question and explain the reason and also explain something about the new tag. Probably users with this privileges will create the new tag for you if found helpful if not they will reply you via comment. Please wait for a while (may be a day!), if no one reply you, flag a question for moderator's attention, choose other and explain there the reason. Moderator's action will be the final. If they decline your flag that means there is no need for that tag.