Career advice into environmental physics or geophysics

Some background: I'm going into the 4th year of my MSci Physics degree at a well ranked uni in the UK. I've been abroad for my 3rd year in NZ so due to the seasons, I couldn't really find time to fit in any work experience/placements during my degree.

I've done a little bit of geophysics(mainly atmosphere and oceans but a little bit of solid earth too) in NZ and I really enjoyed it however my university in the UK doesn't offer it. Because of this I'm taking mainly astrophysics modules this year and doing a research project on exoplanet atmospheres, which I think will be super interesting.

My goal is to work in some kind of environmental/sustainability job where I'm hopefully having a positive impact on the world, not really too concerned about money. Things that come to mind are solar, hydroelectric, geophysics or working for someone like Tesla on R&D would be a dream too. Basically I don't know how to get into this industry. Would I have to do a conversion for a year to become an environmental engineer or would it be best to find a good company to do an internship(potentially unpaid) to learn the basic skills?

I find astrophysics really interesting too but I'm not sure if I would like to pursue a PHD and academia, would there be jobs in that field open to MSci graduates?

Any help would be much appreciated, thank you!