Virtually all environmental groups, parties, scientists and academics who care about the environment wanted remain.
Weirdly, I know quite a few hardcore environmentalists (the kind whose idea of living sustainably actually means living as though it is 1732, albeit with a compost toilet, a bicycle and a biomass fuel stack), and all of them voted Brexit.
Their public argument was that they don't want EU wide rules on the environment (that would apply to the UK) to have to compromise with the needs of German industry or Eastern European economic development, which is a fair point, but I largely suspect, privately, it is more because they see consumerism, global trade, freedom of capital and free movement of people, all facilitated by EU principles, as being anathema to their cause of sustainability.
And I also have to say ... err ... they kinda have another point there too. 
I think any perceived correlation between Brexiteers and climate change deniers is more to do with people who automatically do not accept an establishment line because they essentially distrust most forms of authority: be it hegemonic or alternative.
I dare say if the establishment denied climate change, most Brexiteers would become climate change obsessives.
The question really is why these people distrust authority so much, and why the number of these people is growing year on year. I suspect it speaks to interesting social and cultural dynamics that, unless addressed, are already starting to blow up in our faces.