“More people probably would have attended the event if they knew what “environmental justice” means.”
Rule of thumb: “xxx justice” means, in leftist speak, “justifying socialism with xxx as the excuse”.
“Racial justice”: justify socialism with racial inequalities as the excuse
“Social justice”: justify socialism with gender/sexual inequalities as the excuse
“Economic justice” justify socialism with economic inequalities as the excuse
“Environmental justice”: justify socialism with some hypothetical environmental disaster as the excuse
As soon as an abstract quality like justice has a qualifier, it is no longer justice.