If we mitigate climate change, it will be through carbon pricing. So I support that. Mostly by giving time and money to [https://citizensclimatelobby.org/], as I think their laser focus on passing a Carbon Fee & Dividend is clearly the best plan.
That does not account for other sources/forms of pollution, unfortunately. Yes CO2 is important but it's not the only important thing: many resources are wasted due to planned obsolescence for example.
It's not the only important thing harming the biosphere and GHG emissions are not the only unsustainable human practice. But we are talking here about global warming specifically and that is driven by net GHG emissions.
Methane Action is specifically focused on removing methane, a greenhouse gas 80X worse than CO2: methane alone is responsible for a global temperature rise of about 0.4 C.
So donating money isn't going to change much. Many people with far more money than us have vested interest (some would say actual "shares") in destroying/polluting our planet. Most NGOs are concerned with paying off their employees and selling good-feels to disempowered reformists, not with actual change.
Now if you really want to achieve some change, you can either finance radical propaganda and subversive activities against industrial capitalism (the root cause), or you can with likeminded folks organize a local utopia.
Building a zero-waste (or close to that) neighborhood is not that hard, but requires political and scientific education for all. If your whole area starts composting not burning waste (selling stuff without dedicated packaging), gets rid of Internet Of Turd (IOT) devices, sets up a local electronics/clothing repair shop who also sells decent new or second-hand products, and has a local venue to eat for free if you don't want to cook yourself, you'll be leading by example into an eco-friendly 21st century.
Most people will sell you half-baked solutions because they don't want to reduce energy/resources consumption, they convince themselves we'll find magical fairy dust that makes environmental problems go away. But that's not gonna happen: we need radical change now, and we need to chop heads off of people who get in the way because they want to protect their financial interests against the interest of our entire planet (and all inhabiting species).
