Without going to extreme extents, many of us can lead a more sober life: no plane trip, less meat, insulate the house, avoid fossil fuels on favor of electricity and choose an electricity provider selling only energy produced by renewable ways (no "compensation" or other BS greenwashing). Avoid buying plastic. Choose strongly build appliances ; repair rather than buy. My phone is a 6 year old Samsung under LineageOS so it runs Android 10: good enough and not slow at all.
=> I'm moving at my own pace toward a more sober life, without the guilt of not doing enough. I'm not at all having an austere way of life, just slowly getting rid of the habit of finding joy in buying new stuff. Except what I really appreciate: books, good food, technological product that I really own, that I can hack and repair.

But I totally refuse the self-righteous path of the neo-puritanism that some ecologists promote: as you said, my actions are limited. I'm transitioning to a more sober life, not punishing myself. By the way, many people are just not in an economic situation to, for example, avoid long car commute. But we can all renounce taking planes, at least for vacations. I miss diving in the Red Sea. And I'll never dive in the Philippines nor visit New Zealand. It sucks but at least I know I do more than many - without tying to be perfect.

Once that said, the thing we can do is ... to build a group (friends, family, but most mostly like-minded people) and take responsibility for a piece of land. I'm fundraising to buy a forest of 1 km2 . The idea is to make what his necessary so that this forest will be thriving in 2100 - whatever the climate change. The climate changes too fast for the forest to adapt by itself. We'll need to plant more adapted species.

For the years to come, we are mostly learning since none of us has a clue of what to do. We know that we first need to learn (in books, moocs) and spend a lot of time observing how that parcel evolves by itself. We'll take advice from experts, visit other projects of the sort etc. Then make super small steps to help this small forest transition to the new climate.

That's how we imagine to really reconnect with Nature. We don't have financial gains in sight but the project is not a project of non-humane intervention or forbidding by principle some exploitation. The human beings must - in our view - learn to exploit Nature respectfully: all the species, from insects to birds and bigger animals must thrive. But we will hunt a bit, for our consumption but mainly because it's necessary over here to protect the local farmers' crops. We may also timber a bit, not for sale, nor to heat our houses but to build a few tiny houses over the years. To learn to build a truly sustainable way of life. Sober but comfortable enough, self-sufficient if possible (food aside, we buy food to local organic farms).

Anyway, the priority is the vitality of the forest, not us. But we want to learn how to live in a way that matches with the Nature's needs. We'll try to limit our interventions as much as possible. Especially in the first five years, where we don't plan to act at all, just observe and learn to see.

So I agree, we can't do much to save the world. But we can take responsibility for one particular parcel of Nature, big or small. Let it live, observe and act very cautiously to help it overcome the climate change. Many forests will turn to savannahs if we don't try to plant species to replace those that can't bear droughts and then sudden floods. Some species need a cold winter otherwise their biological clock is lost. They don't cope with the current "warm" winters.

But finding the right species to plant without provoking unexpected side effects is super super difficult. So that's a huge responsibility. Only local people devoting time and love can do this. If it's not us, that parcel of forest will either be cut for wood or be a savannah or yet another commercial zone and its parking lots. A local farmer may also buy it, cut it and grow whatever Monsanto seeds resisting to Monsanto pesticides.

In 2060 or 2100, when the climate and biodiversity situation will become unbearable, our small project will be there, an open-book of what works and what doesn't, in this particular area with its specific soils and specific local climate. We plan to document a lot the experience, so it can be reproduced in the area at least.

Let's not wait for governments and societies to act in time. Let's be the avant-guarde, by nature small groups with obscure projects ridiculed by the mass.

Taking care of a parcel of Nature can't be wrong. Learning how Nature works and how we can cautiously help it adapt can't be wrong. It"s like educating our children into decent human beings: it can't be wrong whatever the society turns into.