First, I'll address your asymmetry comment, with a couple of example points.
> crops
This is a common misunderstanding I see. Crops aren't solely viable because of climate -- a large portion of crop-viability is due to soil quality, which is built up over many many years. As areas that have traditionally been extremely cold become potentially more viable, crops are much less effective because the soil has not historically had a lot of fertilizer-producing flora/fauna.
> decreasing the probability of disasters
As far as I understand climate change, this is not expected anywhere. A disaster can be considered an event that goes dramatically against the norm. For example, flooding [extreme rain], drought [extreme lack of rain], fires [extreme heat], crop freezes/cold snaps [extreme cold]. Climate change essentially results in increasingly extreme deviations from the norm, so "disasters" go up. There's nowhere in the world I'm aware of that is going to get more consistent from climate change.
> make people want to move in
Even if climate were a zero sum game, and some places got better while others got worse, forcing everyone to move would be pretty awful. Further -- it's not a zero sum game, as mentioned in my last point.
The final point I'll make around climate change is that it's very likely to lead to geopolitical instability. As some areas become unlivable, famines, wars and refugees become more and more frequent.
I live in a rather less urban area than most HN readers, but I actually don't know all that much about farming.
I'm fascinated about some of the implications of your comments.
Having seen potting soil and fertilizer for sale in greenhouses and garden centers, I've always assumed soil fertility is a portable, manufacturable commodity. That is, if you want to start a farm in a place with the correct climate but unsuitable soil, you can simply buy healthy soil from somewhere else to get started, and then after a while your crops will establish themselves and create a somewhat self-sustaining ecosystem on your fields that only requires input of sunlight, water and nutrients that are commodity chemicals (nitrates and phosphates that can be mined or chemically manufactured).
Where does the bought soil come from? Established farms. Presumably crops have some capability to create soil from barren earth over time, so you can safely harvest and export 5% of your soil a year, or something. Or you can use dedicated compost piles which produce soil from crop / livestock waste. Perhaps occasionally importing rocky / sandy / clay soil to replenish the base mass.
You seem to disagree with this view; your comment instead implies that soil fertility is more fixed, not fungible. I find this interesting, and want to learn more.
The "AMOC" might stop, in other words. Maybe not? Let's hope. But is it worth the risk of pushing things so far that we might just find out?
Most of us don't live in Siberia or Greenland. Sure these places might become great because of climate change, but it doesn't matter, since barely anyone lives there.
In the places were we do live, the temperatures are already (semi) ok, meaning that increasing these temperatures will bother more people than it will help.
Furthermore, most people live close to water, which means a rising sea level will be bad for them. Maybe (probably not, but just imagine that) after the sea level has risen we have more viable land that is close to water. However, at that point all the current cities have been ruined by it, because they were built for the old water levels.
"Billions of Acres of Cropland Lie Within a New Frontier. So Do 100 Years of Carbon Emissions: Crops grown on this land could feed a growing population. But if these soils are plowed, they could unleash as much carbon as the U.S. emits in more than a century." https://insideclimatenews.org/news/12022020/agricultural-fro...
And I don't think people should be able to downvote a question without answering, or upvoting a response that addresses some criticism, I agree it sucks.
Some areas may become more livable, but we're talking the extreme northern reaches of Canada.
For example, people don't want to live in the Rust Belt because the winters are too cold. Could the region's economic viability increase if winters get milder?
In some places, climate change makes things worse for growing crops, makes people need to move out, or increases the probability of disasters. Everyone is talking about this.
In other places, climate change should be making things better for growing crops, making people want to move in, or decreasing the probability of disasters. Why is no one talking about this?
What's up with the asymmetry?
Edit: Wow this got downvoted fast. I was hoping to get meaningful answers to a genuine question from knowledgeable people with minimum political agenda, but apparently the HN crowd isn't good at dealing with even slightly contrarian takes on this issue.