[johnmorrison]

> drought and desertification

This is an issue, but increased atmospheric carbon and the latitude land distribution of the Earth probably means desertification will be net-negative for at least a while. (I don't have a source for this, but I recall reading that we have more trees today than ever in history?) Keep in mind, carbon is what plants eat.

> When every summer, heatwaves take a few of your neighbours you start reconsidering how nice your country is.

This is also a good point, but once again, there are also people who die from cold. I've been living in Toronto for the last year, and there are many people who die of cold in the winter every year, mainly the poor and elderly. It's not clear that global warming is net-negative at the moment for extreme temperature related deaths.

> we're going to have more than a 2°C increase in mean temperature by the end of the century, and maybe 4°C

I don't agree with this. This might be true if population+QoL growth continues and our emissions per capita stay at today's levels, but that won't happen. Like I said, we are going to fix CC by mid-century, and mean temp increase above pre-industrial levels will be less than 1.5°C by 2100 - not 4°C above today's levels.

> Because that's where they arrive

This is a different type of migration. Nobody is migrating internationally because their country is uninhabitable due to climate change, because there are no such countries today.

> About (a), you should probably read this...

Thank you, I'm aware of what's necessary to accomplish this. We are well on our way. If it wasn't for funding and regulatory limitations, I'm pretty sure we could be net-zero by 2028 just based on the technologies we have in development today.

[pjc50]

Desertification is currently increasing: https://www.un.org/en/events/desertification_decade/whynow.s...

> more trees today than ever in history?

Depending on how big you count history this sounds really implausible.

> carbon is what plants eat.

A slogan commonly repeated by global warming denialists, because it's true but highly misleading. Plants also primarily require water, and the temperature rise dries out a lot of places.

[johnmorrison]

> Depending on how big you count history this sounds really implausible.

History := the recorded past (in this case I mean the last few hundred years)

> Desertification is currently increasing

Okay, you're right about this based on the link you sent. In my head I was considering arctic regions / tundra as desert as well, as their recent forestation rate is much faster.

> temperature rise dries out a lot of places

This is true but it also causes other places to become more humid. Higher temperature climate has more liquid water + more entropy ==> more active water cycle on global average. (This is a gross oversimplification but my point is that the increase in temperature is an increase in chaos, and so water that is currently frozen somewhere will be moving around.)

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The important idea to note here is that we can't just ask "does global warming cause more X"? Because the answer can be yes in some areas and no in others, and an increase in X somewhere does not mean a net increase globally.

[ncmncm]

Best current evidence is that the plants whose growth rate is limited by carbon dioxide availability, and so grow faster with higher CO2 concentration, are parasitic vines. Others are limited by other factors.