> At +5C, there is no growing food in any substantial amount outside of high tech,
It seems you have some specific geographic region in mind. Earth has a lot of regions that are more than 5C colder than the most fertile regions.
People adapt. People move. Sometimes they fight wars about it. This has happened many times before.
We're currently living it the most peaceful, prosperous and safest period that humanity has ever experienced. (Despite what social media is tricking our brains into believing). In the future we will surely live through periods that are closer to the average. But I'm not seeing any extinction-level events due to climate change within the next few hundred years.
AGI or nukes, on the other hand, they both DO have the potential to end us as a species.
You seem to think that a couple of degrees just applies uniformly across the planet, or to a specific location, transforming somewhere cold into something which is now suddenly hospitable. That isn't how climate change works. It doesn't mean that Canada will suddenly be nice and balmy year-round; it means that the climate will fluctuate more wildly and wreak havoc on our agriculture, as described in the comment above. The temperature change is a global average, and your local experience is going to be a lot worse at the extremes.
> You seem to think that a couple of degrees just applies uniformly across the planet
I don't believe that at all. I even studied the IPCC for how their various scenarios lead to different levels of increased heat in different places.
When it comes to fluctuations, there are several types. An obvious one is wind, which will probably become noticeably more chaotic with more energy. Another is temperature.
Temperature variations generally depend on humidity and wind. As winds get stronger, that in isolation leads to some increase in temperature variations.
For humidity (both at ground level and in the atmosphere), increased humidity leads to lower temperature variations.
There are also precipitation. Higher temperatures lead to heavier rain (when it rains), and can increase the likelihood of hailstorms.
There are also extreme weather patterns that become more common when it gets colder. While tropical storms and hurricanes increase in frequency in hot weather, more laminar storms ("winter gales") get more common when the weather is colder. I believe this is because the LACK of turbulence/chaos means there are fewer factors that can break up such storms.
This last type is common in places like Canada, Scandinavia or Siberia now, and come almost exclusively during winter.
Btw, the impact of increased temperature on weather is something that we can already observe on Earth today, simply by travelling between different weather zones. While SOME of the extra energy can affect areas far away from where the heating occurs, a lot of the effects are local or regional.
That means that it's likely that Temperate Zone type weather is going to shift a bit to the North, and include a greater proportion of Canada, Scandinavia and Russia. These areas will then get weather more similar to places like the US/German/China today.
The southern parts of the temperate zone is likely to see weather patterns that resemble tropical (or desert) weather zones. Much of the US can be more like Mexico, France can be more like Morocco or Greece, Sothern China more like Thailand, and so on.
This means that areas that get warmer AND dryer (like Spain, Italy and France, probably) will get some of the variations currently seen in Sahara.
But it doesn't mean that the temperature fluctuations get greater everywhere. Some areas become more humid, and that means lower fluctuations.
Btw, for humans, dryer weather can be an advantage, since it allows us to dissipate heat much more easily. For farming it's less ideal. Places like Saudi Arabia could go in the opposite direction, with higher humidity and more rain, farming could become easier, but the risk of wet bulbs could also go up.
Anyway, while it is true that more energy in the atmosphere ON average increases the frequency of most types of extreme weather, it is not true that it will increase all types of extreme weather everywhere.
Ok, but I fail to see why we would want to increase extreme weather on average? Like, if we happen to make some part of the planet a little better for agriculture by accident, while ruining the rest of it, how is that a good thing?
Do you actually believe people think the warming is a good thing?
People want to drive their car, heat or aircon their house, go an vacation and use or consume all sorts of products that require energy to produce.
And even just scrolling facebook means a lot of energy is used in some data center.
This has side effects. Most cars will spew poisonous gas out the back, into the city where people live. Some of them die from those fumes, most don't. People still drive cars, because they think the benefits outweigh the costs.
It seems you have some specific geographic region in mind. Earth has a lot of regions that are more than 5C colder than the most fertile regions.
People adapt. People move. Sometimes they fight wars about it. This has happened many times before.
We're currently living it the most peaceful, prosperous and safest period that humanity has ever experienced. (Despite what social media is tricking our brains into believing). In the future we will surely live through periods that are closer to the average. But I'm not seeing any extinction-level events due to climate change within the next few hundred years.
AGI or nukes, on the other hand, they both DO have the potential to end us as a species.