[mrguyorama]

"5C warmer" doesn't mean a uniform increase in temperature of 5 degrees at all times. It means "5 * the thermal mass of the earth's biosphere" worth of extra energy in an extremely chaotic system that is currently in a local stable point, but doesn't have to stay there.

[trashtester]

Just to clarify. The reason I didn't respond to this one:

> "5C warmer" doesn't mean a uniform increase in temperature of 5 degrees at all times.

Is because I thought it was completely obvious that this is correct. I've seen that several responses thought I ignored and argued that 5C warming would be the same everywhere, while what I meant by "5C warming" was "the effect of a global 5C warming".

What I DID think was the main message was this one:

> It means "5 * the thermal mass of the earth's biosphere" worth of extra energy in an extremely chaotic system that is currently in a local stable point, but doesn't have to stay there.

While I agree that a "5C global warming scenario" may mean that the average temperature in Lyon, and even that the VARIANCE of the temperature IN LYON may go up quite a lot, I did have objections with the hypothesis that the chaos would be the main factor leading to variations in temperature.

While, for the global average, increased energy in the atmosphere may lead to SOME increase in the variation in temperature, I don't think that variations in temperature depends nearly as much on the energy in the atmosphere as other types of extreme weather, such as hurricanes, heavy rain, hail storms etc. (And effects of those, such as destroyed crops, damage to property or flooding).

Changes in humidity seems to be a much greater factor in the variability of temperature than this extra energy has.

If you check the IPCC projections for changes in precipitation patters, maximum and minimum yearly temperatures, you will find that in areas where precipitation is expected to increase, the minimum yearly temperature goes up a LOT more than the maximum yearly temperature goes up, especially so in the sub-arctic part of Eurasia (like Siberia).

Meanwhile, in areas that are expected to get dryer (including Spain, France and Italy), the minimum yearly temperature hardly increases at all, while the maximum temperature goes up a lot more than the global average.

Basically this means that some vineyards in France, Italy and Spain may have to move to more robust crops, like maybe olives. But it also means that new areas open up that may become more favorable to vineyards, for instance in Germany, Poland or even southern Sweden.

[trashtester]

A 5C warming is indeed likely to make a few areas uninhabitable. I'm not saying climate change is not a problem. I'm just saying it's not an extinction event.

But keep in mind that the areas that tend to get the greatest warming tend to be the dry ones. In such places, sweating will still allow human bodies to regulate body heat, if air conditioning breaks down.

[mrexroad]

I think you missed the above comment’s point about risk to stability in a chaotic system…

[trashtester]

That part looked like gibberish.... Maybe rewrite to make it more clear?

[dTal]

From a different comment whose main thrust you also ignored (you are all over this thread with the same fallacy):

>It doesn't mean it's locally always +5C warmer than it used to be; it means you're seeing insane temperature swings in a matter of days, constantly - in both directions, it just so happens that the average is +5C.

[trashtester]

"Wild temperature swings" is already quite common in dry places. Sahara can be below freezing during the night. The IPCC predicts that Southern Europe will get dryer, so they will have larger variations.

More humid areas, especially if they're near coasts tend to be a lot more stable.

I think these tendencies will remain true.

While introducing more energy to the atmosphere is likely to generate more winds (including hurricanes), it doesn't seem plausible to me that (given constant humidity) this will be enough to cause enough variation in temperature to make farming impossible in most places.

If you have some reference (preferably something like IPCC, as opposed to something that could be fringe), I would be willing to reconsider.

> you are all over this thread with the same fallacy

Maybe you could state exactly what fallacy you think I'm advocating for? I'm not saying global warming is something good and that we don't need to worry about.

I just don't think it's a likely extinction level threat, like an asteroid, rogue AI, nuclear war, an alien invation etc. Unlike those others, it's almost certain that we will experience some degree of global warming, but if that's the worst we will face, humanity will survive as a species.

Also, there is a couple of other factors:

First of all, I think many that worry about climate change (beyond those who honestly think it will lead to extinction) really care mostly about all the pain and suffering that global warming could bring at some point, at least to some large minority of humanity. Maybe also that it will cause a non-trivial fraction of the population to die from famine, wet bulbs etc.

I don't think that's impossible (though maybe a bit pessimistic, see below), but I think the fallacy that the these people make, is to assume that we will have a future world without such events. Historically, we have seen that bad things have happend from time to time.

The collapse of the Roman Empire caused half the population to die off (partly due to colder weather). The Black Death caused a similar percentage to perish in many place. The Mongol conquests resulted in large parts of the Eurasian steppes to be so depopulated that they still haven't recovered. Then the were the world wars, Bronze Age collapse, and the list goes on.

The future is likely to bring similar events, too. Climate change could possibly be such an event. But usually, these events are not those we expect, but rather some kind of Black Swan that surprises everyone.

The second fallacy that some climate change fanatics seem to ignore, and this one by choice, it seems: We're still very much in a kind of exponential technological development. 200 years is a very long time, and unless the technological development suddenly grinds to a complete halt, we will have a lot of new options both when it comes to minimizing global warming and also to survive any warming we're not able to prevent.

People seem to choose to ignore this based on a better-safe-than-sorry philosophy. That's ok when dealing with risk that we aim to reduce to zero, as long as the cost is low. Kind of putting on a seatbelt when driving.

What many don't seem to realize, is that this is a luxery belief / first world concern. For someone less privileged, like most countries in South Asia or Africa (and also working class people in the west), access to cheap energy now is seen as really important. That means for such people, some risk is acceptable.

Kind of like if the seatbelt on your car is broken, and the nearest grocery store is 20 km away. Do you walk there, or do you drive the car regardless. To do that risk evaluation, you want to know the real risk of driving without the seatbelt.

Similarly, for those most affected short term by for instance ending most fossil fuel use, the REAL risk associated with global warming is relevant.

And to evaluate that, it's actually really relevant to factor in that humanity is likely to grow a lot in technological capability to face new challenges over the next 100-300 years. How much is a matter of opinion, but zero is unreasonable.

As far as I can tell, the most likely scenario is that Climate Change is going to be a challenge for humanity. My best guess is that in most places on Earth, people will find ways to deal with this challenge. But I'm open for the possibility that 100s of millions might die because of it.

I also realize that global warming could be a factor leading up to a nuclear war. I really don't think it would be the main factor, though. I consider nuclear war as a separate risk category.

Most wars are caused by nationalism or religious conflicts, especially betwen the kinds of countries that are likely to have large arsenals. The obvious current example is Ukraine. It's not a famine that drives Putin, it's a desire to Make Russia Great Again.

Compared to reasons such as nationalism, religion or even ideological conflicts, I think global warming would be a significantly smaller risk factor in terms of how it increases the risk of global war.

Another huge uncertainty is the what population Earth will have in the future. Already, it's pretty clear that the population in most developed parts of the world is going to decline rapidly over at least the next 50 years. Population growth is mostly restricted to South Asia and Africa now, and even in South Asia there are indications that it's going down.

It's certainly possible that this can be reversed completely, but if the current trend continues (and assuming Africa also has this trend eventually), the population could be halved every century. That means we will be only 1 billion by 2300.

On the other hand, if the trend reverses back to exponential population growth, we may be up to 30 billion or so by 2300 (unless prevented by starvation).

This is a huge gap! With only 1 billion, it would be far easier both to minimize global warming and to survive it. With 30 billion, it would be very difficult to prevent global warming and also much harder to deal with it when it comes.

And all of this hinges on us being unable to develop AGI/ASI this century. Which is starting to seem unlikely. Most of the researches in the field seem to expect AGI some time in the range from "within 5 years" to "several decades".

If we DO develop AGI before 2100, the exact circumstances around it is going to matter way more than global warming. At the optimistic end, AGI may find ways to completely end global warming.

Or it could cause human extinction before it matters.

So it's not that I don't "believe" in global warming. I generally accept the scientific consensus in most fields, as long as the field actually uses something like the scienific method, and is not just a cover for some ideology.

It's just that it seems to me that many "True Believers" in climate change turn it into something more similar to a religion than the actual science it's based on. And that this causes them to only see this single issue, while generally ignoring almost all other risk factors we're likely to face in the future.

[mrexroad]

Stability in a chaotic system is precarious. Changes, even if small or seemingly trivial, can cause massive cascading effects from positive/negative feedback loops.

Sigh, I don’t mean to sound like a dick, but if that’s gibberish then you might want to strengthen some of the foundational understandings around systems.

[trashtester]

I'm familiar with chaos theory, and not rejecting issues related to chaotic systems. But this part doesn't really seem well formed:

> It means "5 * the thermal mass of the earth's biosphere" worth of extra energy

Here it seems that the units were missing, at best. The extra energy would be "5K * the heat capacity of the biosphere (in J/K)"

> in an extremely chaotic system that is currently in a local stable point, but doesn't have to stay there.

First of all, I don't think the current state is THAT stable. And when it comes to any disturbance to the stability caused by the extra energy, that's what we have climate scientists for. Specifically, those are the ones that need to assign specific probabilities to the varous scenarios available.

For instance, while it is POSSIBLE that a result of the chaotic dynamics of the system would be that the Gulf Stream got reversed, it seems that the curren consensus is that this is highly unlikely.

However, there are a lot of other effects that would be highly likely, such as an increased rate of hurricanes for instance. But hurricanes is not a state of the whole system, it's basically just a type of weather that gets more common.

So, maybe "gibberish" was not the perfect word to describe it, as I was able to parse it. It's just that it didn't say anything specific. It was more at the level "It's getting chaotic, and chaos is scary", without making any specific predictions or producing references.