Those are great ideas! There are actually some amazing environmental science and environmental policy programs at various schools. I’ve been helping a girl who wants to focus on those areas so I’m familiar with some of the options 
You should look at Wash U in St Louis specifically: they have a full ride scholarship that is specifically for students who want to major in the sciences, including environmental science (highly competitive, but still!). Wash U also has some great writing courses in their English department, and I think it would be easy to grab a minor, or even double major, there.
And life is weird–you never know where you’ll end up! I majored in journalism, dead set on being a journalist, and now I work in international TV marketing. In hindsight, it makes perfect sense–I love TV, I’m a strong persuasive writer, and I’ve lived abroad/always loved language & culture… and here I am. With love to journalism, what I’m doing now is more stable and pays better than journalism would. But 18-year-old me was dead set on it… and j-school was actually amazing and I don’t regret it at all. So you could end up any number of places!