Please help me identify this ww1 uniform.
Having searched around the suggestions above, I eventually found this badge that is listed as a Imperial Russian Fire Society badge. As you can see, there are several similarities between it and the badge in your picture; the helmet and crossed axes mainly.
So, I'd agree with the others when saying that it appears to be the uniform of a Russian firefighter in the years leading to the revolution.
It's a fireman. If FD is for "fire department", he was a fireman probably somewhere in the US. Is the 2016 his badge ID?