Does this career exist, and if so, what should I study to achieve it?

One thing you could study is environmental science or any kind of science really. I would look at Earthwatch.org. It is an organization where people pay to participate in a science expeditions. They have fellowships for students. There are many places you can volunteer to get experience like aquariums, zoos, natural history museums and conservation organizations. Maybe you can work at a travel company. Some specialize in green travel. You are definitely going to have to learn another language if you don't speak one already. You can also look at companies that make environmental products. Unfortunately, I don't live in the UK so I don't know much about the schools but many universities have environmental programs. Good luck to you.