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Comment by ljf | Hacker News Reader

I think the issue is for the animals that actually need a colder climate and/or rely on ice/snow cover - a warming world won't give them a new space to move to (yet).

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One anecdote/example that has stuck with me is a heard of caribou in the Canadian north. In winter, they typically dig through the snow to find plants to eat. One year, with rising temperatures, a large area was left with a thick layer of ice on top of the snow. Precipitation was falling as rain (instead of snow) due to warmer temperatures, then freezing overnight creating this thick layer of ice. The caribou couldn't punch through the ice and ended up starving to death resulting in a mass die off.

The ones that survived will have had more efficient metabolisms, or harder hooves that could break through the ice to get to the food, or could have learned a technique to cope. Hopefully their next generation will retain those traits or that culture to adapt.

Bigger animals have low numbers, larger ranges, less genetic variability, longer reproductive cycles, evolve much slower, and tend to go extinct much more reliably.

Or they’ll just go extinct. Not all species will adapt.

Yeah, animal species definitely successfully evolve over the course of a dozen years /s

I don't think GP's comment shows the lack of understanding of evolution that you're trying to point out: numerous similar events occurring to a range of herds over a period of time is exactly how that would happen isn't it?

Not to say I agree (or not) this particular case would be effective, or that it's fine for man's influence to cause it, or anything. Just I don't think they showed any sign of thinking caribou would suddenly evolve like a Pokémon to have a stronger hoof or something.

Yeah ... animal (and plant, etc.) populations in a stable environment have a lot of random variations that confer no outright distinct advantages over their peers, they are distributed along the normal plane to the current evolutionary gradient. When environments suddenly change, it's not like animal populations rapidly create new random mutations that confer advantages in subsequent generations. Rather, the new conditions make previously existing traits that some animals within the population had and others didn't have more significant to survival, and so those advantageous traits are emphasized in subsequent generations.

After this "evolutionary bottleneck", other new random mutations / variations will occur generations later that might have no seeming immediate advantage / disadvantage to the "new normal", but at some subsequent change in the environment, the cycle of weeding out "bad" traits will happen again.

Lots of fruit trees need an accumulated number of cold hours every year. I've seen warnings about some plantings already having issues with not producing enough fruit.

We may lose the sea ice and continental glaciers, but we'll probably still retain some ice with the intersection of extreme altitudes and extreme latitudes, at least for our lifetimes. A place like Denali is a lifeboat.

> A place like Denali is a lifeboat.

I think this is more accurate than you may have intended. It will be a single lifeboat, when the Titanic is sinking. Quite useful if you can get on it, and would guarantee survival, but for an awful small number relative to how many would like to be onboard.

The supposed Biblical Ark only held 2-7 of each animal. Denali is a big mountain, and will make a rather large zoo or a small nature preserve. But there are other Arctic ranges with less extreme altitudes that are going to prove useful as well in the "extremely alarmist and not worth considering seriously" scenarios that some of the data suggests we're heading towards.

There is a question of whether there will be any space, what with all the condos. But humans are less constrained, having invented the pressurized condensation-evaporation heat pump refrigeration cycle, than the natural world.

Yep but the Titanic is the whole planet and there isn't a place to get yo safety on such a lifeboat.

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