I think it's great to have "help fix the climate" as a sort of stretch goal for someone's cool project, it's just not something I'm going to take particularly seriously. Maybe they'll produce a couple mammoths who get sold to zoos and then get bored and move on to their dodo resurrection instead.
I worry that they can use the climate change argument to deflect from the ethical arguments around whether it's even a good idea to resurrect a highly intelligent social animal like this. Imagine bioengineering a resurrected "Neanderthal" into a world without Neanderthals. There's something bleak about it. If the breeding/release idea doesn't work out you've just intentionally created some endlings[0] with no real future.
Asimov wrote an interesting story that has a similar premise.[0] Since I read it as a child I have wanted to see cloned hominids.
I think that in the near future we'll wealthy weirdos start to clone their ancestors, and things like native groups in colonized places like Canada or New Zealand start to clone their ancestors to buff up their population and strengthen their legal claims to territory. Think about what we'll be able to do with artificial wombs.[1]
As for your neanderthal endlings it probably will be pretty bleak for a lot of these hominids, but who knows, maybe some of them will end up being smarter than your average human and they'll have a role in society.
I worry that they can use the climate change argument to deflect from the ethical arguments around whether it's even a good idea to resurrect a highly intelligent social animal like this. Imagine bioengineering a resurrected "Neanderthal" into a world without Neanderthals. There's something bleak about it. If the breeding/release idea doesn't work out you've just intentionally created some endlings[0] with no real future.
[0] https://en.m.wikipedia.org/wiki/Endling