If the world was composed of countries living at the quality of life of Western Europe or America and with that level of technical and economic expertise this would I think be reasonable, but in fact billions of people are living hand to mouth. Look at the effect that Syrian migration to Europe or indeed Mexican migration to the USA has had on Western politics. Now imagine instead of 5 million people from Syria 100 million or 500 million are on the move? Is the population of Bangladesh going to gradually relocate, and if so where to? Its nuclear armed neighbour on one side, with their own hundred million to be displaced from subsistence agriculture, or the country conducting ethnic cleansing on the other? You have assumed a greater degree of stablity than is reasonable.

People will primarily move more inland within their own countries. Some cities will be raised. Neighboring countries will absorb some. Small border shifts may happen, as have happened for centuries.

You have no reason to believe this.

From: https://www.esquire.com/news-politics/a25422366/trump-ambass...

"The fourth and latest National Climate Assessment put together by 300 scientists from 13 agencies of the U.S. government and released last month found that climate change is real, man-made, and will cost the U.S. 10 percent of its economy by 2100. Midwestern farmers will lose 75 percent of their crop yields, and trillions of dollars in coastal real estate will be at risk. The wildfires out west, already unprecedented in their destruction, will get worse. Hurricanes and typhoons will grow more ferocious. Epidemic diseases will flourish."

And that's just for the US. Large portions of Africa and the Middle East are predicted to become uninhabitable. The threat to human life on a time-scale of 100 years or more is gargantuan.

"Midwestern farmers will lose 75 percent of their crop yields"

and other farmers will benefit and have increased yeilds. I don't mind facts. But misleading ones I do mind.

Misleading?

Wow, by 2100 it will cost the US 10% of its economy? You mean a small size recession? And you all are such a fuss about? And for that you want to deprive 3rd world people from gaining the same benefits you get from energy?

This is alarmism on the grandest scale and a horrifying hypocritical at that. There is nothing we can do about CO2 right now. We can just continue to work on safer and cleaner ways to generate electricity (atomic mainly, fusion hopefully, solar for the local homes, etc.)

The predicted costs of tackling it are significantly lower, so why not just tackle it and avoid the recession.

Also, a permanent loss of 10% is not a small recession, most recessions lead to no permanent loss, just a demand shock which is made up afterwards. A permanent loss of 10% is more like the financial crisis, and I’d rather avoid that if I can. One brought Trump and Brexit, I’d rather not add another to the mix.

Alarmism was never so appropriate. We have so much to lose.

People living in Western cities doing desk jobs, living in a globalized flexible economy can just be moved inland, and their food supplies can shift from one commodity food producer to another. That is, assuming these commodity food producers remain stable and invested in the global trading system. People who are subsistence farmers rely on their land to live. You cannot just move those people ‘upland’ away from the agricultural land which feeds their continued existence.

what what what? that is a nightmare scenario.

If anything like countries needing to move inland happens it will mean that the world is already in economic ruin and the survivors are in a roadwarrior/madmax style existence.

if this needs to happen, the world will in a such a state that YOU will not be able to buy a beer or watch tv.

I think very few people actually worry about it. That's not representative of the people who post here, but just looking around at how people live and the cars they drive and the homes they build and businesses running 24x7 with all the lights on, parking lots lit up all night after stores are closed, towns wasting many kilowatt hours on Christmas lighting, etc. I see no real evidence that anyone but a small minority of people are even thinking about it, much less worrying.

"Gradual relocation" of several billion people will be extremely challenging and unfathomably expensive even on a half-century timescale. Barring a way to physically transport entire cities along with buildings, roads, and infrastructure, I don't see any way that "technological progress" can substantially change that.

Buildings don't last forever. "Ideally, the average lifespan of any concrete structure is 75-100 years. But, it is considered that the average life of an apartment is 50-60 years while of a house it is 40 years." [1] Older buildings have been actively maintained.

Designing new cities without the cruft of older ones is a huge opportunity. However, it's likely that most building owners will just add couple extra meters of dirt below when it comes time to rebuild a given structure. Even skyscrapers do not last forever.

[1] https://www.makaan.com/iq/buy-sell-move-property/what-is-the...

[2] https://www.quora.com/What-is-the-life-expectancy-of-a-Skysc...

Moving a city is not as simple as saying "any time a building wears out, rebuild it 100/500/1000 miles away, repeat until finished." At the very least, there's logistical issues and economic disruption at both ends. It may be possible in theory, but, again, extremely challenging and unfathomably expensive. And humanity has a well-established track record with anything that involves committing vast amounts of money now to save a bunch of people, mostly strangers, in a few decades.

Moving to better cities does not require intervention. People will do it naturally over time.

Are you now claiming that climate change isn't a big deal because the billions of people whose homes are flooded, or too hot to survive, or otherwise uninhabitable can just...go somewhere else?

In today's world, we see (much smaller) groups of people trying to relocate as their homes become intolerably dangerous. The press calls it "the refugee crisis" and it's causing massive tension all over the world. What do you think will happen if the flow of refugees continues increasing, year after year, for decades?

Yes. That’s pretty much what I said in my first comment.

It’s not a huge deal. It’s a moderate deal.

Moving cities is not a huge deal. I’ve personally done it 3 times. It’s not a small deal either, don’t get me wrong. But it’s not a mayday scenario.

Even my ancestors who made 1/100th the income I do moved multiple times.

You don't see the difference between you trying to find a new place to live, and you plus 100 million other people trying to find a new place to live all at the same time? I'm starting to think you're just trolling.

You really dontgey what the problem is.

And no, it has nothing to do with income

> Gradual relocation will be our primary means of fighting it.

That highlights what's wrong with your PoV. If sea-level rise were the only issue, your comment might actually make some sense ... but that's not the case. Climate change will also lead to droughts, floods, famine, conflicts over water, species extinction, possible collapse of entire ecosystems, and a host of other ills too numerous to mention. Normal technical progress isn't going to solve biodiversity problems we barely understand, or human-society problems that will be driven by warming. It would require a major leap on par with the birth of atomic physics or molecular genetics. Maybe more than one. You want to talk about what's rational? Faith in the modern equivalent of miracles is not rational.

Yesterday's false cry of "Wolf!" is the worst enemy of action today. Will today's cry of "Wolf!" inhibit action tomorrow? It pays to be correct -- and hurts to be incorrect.

FWIW I'm convinced that it's serious this time, but history abounds with examples of breathless malthusian doomsday predictions that failed to pass.

When has happened"cry wolf"?

If we were truly concerned, we should work on eliminating water vapor, since that accounts for much more of the greenhouse effect than carbon dioxide.

Or, pump out even more carbon dioxide to increase the warming and water vapor, and hence increase cloud cover to cool the earth.

Provocatively worded... but intriguing from an engineering POV: if it is too late to limit CO2 levels and return to pre-industrial levels, what levers do we have to control water vapor levels?

Nothing. Water vapor is always in equilibrium with oceans on the timescale of weeks. In other words, any excessive water vapor you manage to put into the atmosphere will simply rain down.

http://www.realclimate.org/index.php/archives/2005/04/water-...

Not so fast, please. The very link you provide refers to the Pinatubo eruption that caused a significant multi-year cooling. It is well-known that cloud albedo changes in response to the addition of aerosols, which ultimately changes cloud water content (rapidly adjusting equilibrium with changes in global sea-surface temperature). Thus, there is at least one lever of action that we know of.