error reading Environmental variables in C

I am trying to read an environment variable on windows platform. I made the variable global as I intend to use it through various function. This is what I tried

#include <stdlib.h>
#include <malloc.h>
#include <string.h>

char* devset = getenv("DEVSET"); //1 for debugging, 0 for normal execution

I get the error

C:\Users\Prateek\Documents\Script Parser\main.c|6|error: initializer element is not constant

I tried the same thing in main, it compiled and I didn't get any errors. However this way I will be required to pass the environmental variable as an argument to all the functions. Is there another approach to make the environment variable globally accessible? Any help appreciated.