Can I change this '下‘ for '前面‘？
No. The grammatical pattern is 


  在x下


which means "with x as true/under". An example would be: 


  在共产党的统治下，中国变强了。


So the sentence means something like (though it's kinda hard to translate this semi-literally without sounding very weird): 


  With a green and environmental world as the consensus background for
  society...