Chemistry is not exactly the worst enemy of the environment. Its actually not at all an enemy, we ( the humans) have made it into one. Plastic, which is one of the leading causes of global warming was invented by chemistry. In fact behind every cause of global warming, there is some kind of chemistry behind it. Anything that not natural is considered bad for the environment and what can be more unnatural than chemicals???
Due to chemistry, we have learnt about and also discovered new elements, some of which are helpful to mankind and some which that aren't. The impact of the life threatening chemicals is much more than that of the ones that help us. For example uranium causes high level of radiation, which effect cannot be reversed by any other element. You want chemicals?? How about hydrochloric or sulphuric acid, which cause SOME damage. Chemicals are continuously and irreversibly damaging the earth. It's ripping a hole in the ozone. Well, chemistry isn't. We are. But I still believe that we would have been better off without this much development of science or chemistry.