[johnmorrison]

You're right, GDP growth does not outweigh deaths. However I don't think the primary issues caused by climate disruption will be human deaths, but instead the loss of assets in compromised areas. Humans will relocate, and lose a lot of wealth, but why would they die en mass?

> fleeing their then uninhabitable countries ... which will lead to millions of death

I'm not sure if this is true, actually. What is true is that millions of people every year die due to air pollution, but this isn't climate change, it's just our present pollution.

There's like ~50 million deaths per year if I recall correctly, and I'd be very surprised if more than 0.1% of that is caused by climate change. At least 5% of it is due to pollution, though, and I think probably more like 10%+

[littlestymaar]

> Humans will relocate, and lose a lot of wealth, but why would they die en mass?

What a wonderful world you live in. Do you genuinely believe it's that simple?

What do you think happens when 1 million people move from one country to another? They do not simply relocate, they are parked in camps (if you want current examples of that look at the Rohingya people, or Syrian refugees in Lebanon) until they can go back home, as you can guess the sanitary situation of these camp is more than precarious (cholera is a big threat for instance). With climate change, their will be no way back, and it's not going to be one million of people, but hundred millions.

What do you think would happen if a country, let say Italy for instance, had to park 10 million people in camps for years? Don't you think people in camps would eventually revolt violently to get out? What would Italians do then? Don't you think European countries would anticipate this outcome and just block refugees from entering, shooting the one trying to? Because it's already in the political agenda of most far-right parties here in Europe, and most of them are not that far from power (Salvini and Orban and just the first of a long series coming…). Due to the fight against illegal immigration, there already been thousands (around 17 000) of death in the Mediterranean see since 2014. And you can be sure it's not going to be better when all central Africa is uninhabitable …

And when people fleeing their countries are not accepted (as in “parked”) in neighboring countries, they just wander in the wild until everyone is dead. That happened for instance to people fleeing Rwanda to Congo.

Large scale population migration are incredibly difficult, and they almost always go wrong, and least a bit. Expecting 1 to 10% of the refugees dying isn't that pessimistic. From the figures discussed earlier, that mean between 2 and 150 million death. Which comes in the same ballpark as the biggest humanitarian disaster of the 20th century…

[johnmorrison]

I feel you're conflating two different types of migration, and the issue isn't nearly as big as your 150 million deaths figure.

Almost all countries have ample space that will still be habitable for their entire population in 2100, even if climate change is left unchecked.

Those that don't represent a small portion of the global population, certainly less than 500 million people. I grew up in Botswana, and I know that "all of central Africa is uninhabitable" is not a likely outcome anytime soon. Most of Africa is actually really good land to live in, and will continue to be fairly good through the century.

In any case, Italy does not need to "park 10 million people in camps". Italy is a tiny country in terms of land area, so why would they need to take so many? Russia and Canada alone could easily fit a few billion immigrants each if global warming is really severe in a few centuries.

The notion that the only solution to climate change is to move everybody into already crowded places doesn't seem to have a base. We can solve the migration problem with or without moving people into Europe.

Anyways, my core point here is (a) we won't need to deal with this migration anyways, because we will solve climate change way before it becomes necessary, and (b) even if we didn't lower our emissions, I'm confident we can solve the migration problem without millions of deaths.

[pfbtgom]

I'm less confident that a mass migration wouldn't result in millions of deaths. An example might be the partition of India and Pakistan in 1947. Only 14 million displaced, yet an estimated 200k-2 million deaths and another 2 million people missing[1]. In many ways, this planned displacement was a more favorable scenario than a chaotic climate refugee situation.

If we don't have a good answer to the relatively simple refugee migrations now (eg. Central America, Syria), then I have extreme pessimism that we will be able to manage a larger-scale, persistent event. Whereas with economic + political refugee situations we can always hope to resolve the root cause, with climate change it is simply the new normal.

[1] https://en.wikipedia.org/wiki/Partition_of_India

[pjc50]

> Russia and Canada alone could easily fit a few billion immigrants each if global warming is really severe in a few centuries.

Russia absolutely isn't going to do that, and who's going to pay to move them across the Atlantic to a country that they're not allowed to immigrate to?

I'm kind of leaning the other way: millions of avoidable deaths is the "normal war" situation, even if we magically solved climate change tomorrow.

[1337biz]

Oh interesting, so you pretend to know how Russia will act in 100 years from now. Interesting science you got there!

[littlestymaar]

> Almost all countries have ample space that will still be habitable for their entire population in 2100, even if climate change is left unchecked

That's a really dubious one. There's multiple issues with global warming, drought and desertification being one of them (and it probably will not affect a whole country) but the second one is just the max temperature the human body can, withstand especially with high humidity. When this threshold is passed, you can have thousands of people dying at the same time in your country. When every summer, heatwaves take a few of your neighbours you start reconsidering how nice your country is.

Remember, we're going to have more than a 2°C increase in mean temperature by the end of the century, and maybe 4°C. 4°C is the difference between now and the last ice age when the whole Europe was covered by huge glaciers.

Also, many people live near shores, which will be damaged frequently as the see level rises… How would India, who have a borderline genocidal tendency (fantasised mostly at the moment buy still frightening) against Muslims nowadays, react to the massive arrival of Bengali people coming from Bangladesh after a typhoon destroyed their land?

> Italy is a tiny country in terms of land area, so why would they need to take so many?

Because that's where they arrive… I'm not speculating when I talk about Italy, this is happening right now (not 10 millions, but hundred of thousands).

> Anyways, my core point here is (a) we won't need to deal with this migration anyways, because we will solve climate change way before it becomes necessary, and (b) even if we didn't lower our emissions, I'm confident we can solve the migration problem without millions of deaths.

Regarding (a), you should probably read this https://en.m.wikipedia.org/wiki/Emissions_budget

Regarding (b), I admire your confidence, but it sounds delusional in regard of the whole human history.

[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.)

--

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.

[biolurker1]

cultural conflicts are the issue. There may be space in Italy for another 30 million inhabitants but soon you will have Muslims fighting Catholics (and getting slaughtered). That's a humanitarian disaster in my book