The human race is basically just screwed. Warming is going to happen on a massive scale and there is little anyone can do to stop it. In 50 years, we'll be killing each other over the remaining usable farm land. Until then, we'll keep buying SUVs and burning more oil.
> Actually, the farmland will just move. Northern regions will become more arable. There will be disruption but maybe nothing we can't handle.
Even if we ignore the effects of increased variability (which makes investing in production anywhere less secure) and just consider, as you do, the averages, this is problem for people as long as countries and borders are a thing, because shifting where its possible for humans to support themselves has some pretty drastic consequences.
When we lose the wild species of the plants we eat, we start running a huge risk that any future disease wipes out that whole cultivated species, and our existing ways to manage this (selective breeding, or transferring genes from the wild plant) lose the material they depend upon.
Coffee is one worrying example. It originates from Ethiopia and Sudan, in the mountains, at particular altitudes (temperatures). As temperatures rise, it grows higher — but we soon run out of soil on the mountain, or run out of mountain altogether.
You're not considering the politics. The arable farmland will "just move" into different countries. Russia, Europe and Canada win. Africa, India, most of Central and South America and China lose.
It's not literally a war over food where the winner gets to eat. It's riots because food in North Africa triples in price because it has to be transported from Russia or Europe instead of grown locally and people are angry but the local government has no capacity to fix it.
The thing about food riots is, they are over quickly because, starvation. So a very temporary condition.
And in this modern age of transportation there's really no need for anybody to go hungry. We can feed everybody. If somebody in North Africa is hungry, its their politics at fault.
> The thing about food riots is, they are over quickly because, starvation.
Food riots usually happen well before mass starvation, and usually are over quickly because one of four things happens:
(a) The government accedes to the demands of the rioters, or
(b) The government distracts the rioters, often with a manufactured external crisis, or
(c) The government convinces the rioters that continuing the riot will lead to more pain than whatever provoked the riot and no positive results (often, by fairly direct demonstration of this),
(d) The riots escalate to outright rebellion, and the government is toppled and replaced (often resulting in [a], but sometimes this becomes a distraction along the lines of [b]; this often follows an attempt by the government at [c].)
> And in this modern age of transportation there's really no need for anybody to go hungry. We can feed everybody. If somebody in North Africa is hungry, its their politics at fault.
Even granting that, manifestly people do go hungry, particularly in nations that don't generate enough domestically to feed their people and would have to rely on imports to do so (though, even in the most developed countries that are also net food exporters, some still go hungry.)
Climate change, even before considering increased variability, changes which countries political deficiencies produce major food distribution problems and the accompanying pressures, which, historically, have led to mass violence, both internal and interstate. That its a political and not technical problem might be emotionally satisfying, especially when the problem is mostly in distant countries, but it doesn't actually magically make the problem go away.
> The thing about food riots is, they are over quickly because, starvation. So a very temporary condition.
Your answer to food riots is don't worry, they'll starve to death soon enough?
> And in this modern age of transportation there's really no need for anybody to go hungry. We can feed everybody. If somebody in North Africa is hungry, its their politics at fault.
We can grow enough food for everybody. We can put the food on trucks. We can put the trucks on roads.
Somebody still has to pay for the food and the trucks and the roads. And that's going to be significantly more expensive than locally grown food. For people who have no money to begin with.
> And that's going to be significantly more expensive than locally grown food
Depends on the food and the transportation method. Is growing tomatoes in a green house during winter months in a northern country more or less efficient than shipping them from the southern hemisphere?
> We can also put the people on trucks or planes or boats and move them to where the food is.
We could, but the people where the food (and associated economic security) is may object to that.
Refugees often aren't all that well received, and economic refugees (as opposed to political refugees who are politically aligned with the receiving state, which is opposed to the regime from which they are fleeing) -- external and, often, internal -- often are the worst received.
> Why should I expect that to result in us killing each other over arable farm land, any more than we're killing each other over arable farm land now?
Arable farmland and access to fresh water have been a fairly common thing for people to kill each other over historically, including in the modern era. To the extent we aren't, its because many countries have reached settled states with their neighbors that are stable given a relatively stable distribution of those resources.
Major shifts would leave large existing populations without support and others newly prosperous, giving the former little to lose and the latter something quite valuable to defend.
Yeah, but those without are going to be continents away from those 'with'. Not really in a position to fight, especially as they're starving. Not talking knights in armor fighting over a moor here.
> Yeah, but those without are going to be continents away from those 'with'.
No, they aren't. The US will be one of the losers, Canada one of the winners (again, ignoring effects of variability, etc.) And lots of the relative winning/losing pairs are going to be immediate neighbors.
> Not really in a position to fight, especially as they're starving.
There'll be a whole long period where the losses will be to established economic position rather than mass starvation. Its not going to be "breadbasket today, wasteland tomorrow". There'll be a long period where declining economic position, rising food prices, and less food security (and similar effects with water in place of food) will be evident and starvation visible down the road before mass starvation -- and its in that period that there will be strong pressures on governments to reverse that position by any means at their disposal.
Maybe the average temp/rainfall moves north in some places, but doesn't the variability also increase delivering more frequent swings into extreme conditions, in turn causing more frequent crop failures?
True. But in modern agriculture, the soil is irrelevant. Corn in Iowa grows because of Anhydrous Ammonia applications. That's it. Eroded clay hillsides produce as well as (or even better than) black loam. So no worries there.
Considering that we are still moving out of an ice age I don't really expect are burning oil to be an issue that will have a noticeable effect. Consider also that crops do better as CO2 concentrations rise. If anything the world can easily use and withstand a little warming.
One other interesting thing to consider, we really are not even using a good percentage of land that could grow food. There are many parts of the world that because of conflict do not fully use the lands they have and in many western nations the majority of land is held by government and not open to use.
