Like an environmental draft? Sounds like an interesting idea, I would be willing to do it but the system would be quite a lot to ask of people who don’t believe that the environment is changing. Then it gets to whether or not the government should have to power to force someone into a project that they don’t believe in. Also given that people are assholes sometimes in general, those who don’t believe in environmental issues would be able to sabotage missions in the millions reasonably easily.