I am going to uni in September, how can I begin working in climate science?

The recent heatwaves in the UK have made me committed to actively working in climate science, to research climate change and help install ways to combat it. I don’t want to look at the devastating effects around me and pretend I am completely helpless when I am not only willing and capable but also in a stage of my career early enough to try and make a difference. However I have no idea where to start and I would love some advice on how I can begin transitioning into this career. For context I will be studying mathematics at university and based in London for the duration of my degree. I am considering volunteering work but I don’t know what of work and which firms or organisations. I have a bit of research already but I would appreciate any advice that I can use as a starting point for now. Thanks!