Activism is the practice of strong, vigorous support (through action) in support of or against a controversial issue. Environmental activism efforts include battling climate change and greenhouse gas emissions, defending the oceans, protecting forests, creating a toxic-free future, campaigning for sustainable agriculture, protesting animal testing, promoting vegetarianism/veganism, protecting endangered species and many more. (Source: Merriam-Webster Dictionary, Greenpeace / Photo: Flickr)