Emissions are a large part of what's causing the habitat destruction, depending on where, specifically, you're talking about. For instance, the warming oceans are caused by the increasing CO2 levels, and warming oceans and ice cap melt is causing massive changes in weather patterns, which in turn, is leading to droughts, floods, increased wildfires, more and stronger hurricanes, etc. Deforestation in the Amazon is still an ongoing problem, although I understand that the president of Brasil has instituted a program that takes land back from ppl that illegally burned forests to turn it into grazing land. (I think seizing the cattle would help too; the large-scale rancher that do that need to be bankrupted.) Microplastics are definitely A problem, but I don't think that we know how much of a problem they are yet, in that we're not entirely sure how increasing levels of microplastics in animals, etc. is going to affect them in the long term.