Caused by... Anthropological climate change due to CO2 dissolution into oceans' waters, so it's a subset of the larger issue, fix pumping CO2 into the atmosphere then tackling ocean acidification becomes more easily approachable.
I found a permaculture community and found a guy who loves to tend to the land but has no money, so I gave him a downpayment to buy an 8 acre piece of land about 2 hours away from me.
> letting it go fully natural
The piece of land we bought was fully natural for a long time and it wasn't pleasant when I first visited. It was extremely thick and hard to even walk about, so the first step we had to do is clear it out to make a living space.
You could start a land trust of some kind. Massachusetts has a huge one called the Trustees and many of the best hiking trails and beaches are actually Trustees land. It’s private, but generally open to the public. Tax-free for them, which would be better than you paying property taxes on unused land.