We're in an interglacial period of a large scale ice age. Specifically, we're at the end of an interglacial awaiting reglaciation. — Tate

Not according to the WIKI entry on Ice Ages:

"Earth has been in an interglacial period known as the Holocene for around 11,700 years,[47] and an article in Nature in 2004 argues that it might be most analogous to a previous interglacial that lasted 28,000 years.[48]"

This suggests that we are around the middle of an interglacial period, not at the end of one. Can you cite a reference for your claim that we are at the end of an interglacial period?

You seem to be reverting to your "fool" status.

This suggests that we are around the middle of an interglacial period, not at the end of one. Can you cite a reference for your claim that we are at the end of an interglacial period? — Janus

"..the last four interglacials lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stands. These data suggest that an equally long duration should be inferred for the current interglacial period as well. Work in progress on Devils Hole data for the period 60,000 to 5,000 years ago indicates that current interglacial temperature conditions may have already persisted for 17,000 years."
here

The conventional wisdom for sometime has been 500-3000 years. The trigger is cold winters in the northern hemisphere.

The conventional wisdom for sometime has been 500-3000 years. The trigger is cold winters in the northern hemisphere. — Tate

What "conventional wisdom" is that? Do you have a source? The information from the source you did cite seems to have been cherry-picked by you:


"How long can we expect the present Interglacial period to last?

No one knows for sure. In the Devils Hole, Nevada paleoclimate record, the last four interglacials lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stands. These data suggest that an equally long duration should be inferred for the current interglacial period as well. Work in progress on Devils Hole data for the period 60,000 to 5,000 years ago indicates that current interglacial temperature conditions may have already persisted for 17,000 years. Other workers have suggested that the current interglacial might last tens of thousands of years."

"Lasted over ~20,000 years": how long is that 20,000 years, 23.000 tears, 25,000 years? "May have persisted for 17.000 years" May it have persisted for 15,000 years then? Also, it is widely accepted that the durations of past phenomena are not reliable indicators for the duration of subsequent phenomena. At best they are all we have to go on. Hardly good grounds for "between 500-3.000 years, or for claiming that we are at the end of an interglacial period.

Whta "conventional wisdom" is that? Do you have a source? The information from the source you did cite seems to have been cherry-picked by you: — Janus

C'mon, man. My sources are all books and articles. You're looking for an internet blurb. Be a human, why don't you?

C'mon, man. My sources are all books and articles. You're looking for an internet blurb. Be a human, why don't you? — Tate

It has nothing to do with "an internet blurb" or "being human"..You linked the source. If you have others, then quote them to back up your claims, Otherwise you cannot show your opinions to be anything of greater authority than those of just one more opinionated dude on the internet.

You linked the source. If you have others, then quote them to back up your claims, Otherwise you cannot show your opinions to be anything of greater authority than those of just one more opinionated dude on the internet. — Janus

I linked that source because as far as I know, it represents the standard answer. For some reason the Wiki article is highlighting one article from Nature and not emphasizing the standard range of answers. So I'm looking.

It actually is about being human.

This is a study from 2013 about summer insolation reglaciation triggering. It upholds the standard view that we're fairly close to a trigger point now since we know summer insolation is at a minimum.

If you want a simpler narrative, I would advise a climatology textbook. There are some good ones out there

:roll: No fucking way :point:

https://thephilosophyforum.com/discussion/comment/722883

It's true

No fucking way :point: — 180 Proof

It's true — Tate

Yep, it's true; no fucking way.

:smirk:

Yep, it's true; no fucking way. — Janus

Wow. Tough crowd.

:cool:

Wow. Tough crowd. — Tate

That's 'entertainer' talk. Are you just here to entertain?

This is a study from 2013 about summer insolation reglaciation triggering. It upholds the standard view that we're fairly close to a trigger point now since we know summer insolation is at a minimum.

If you want a simpler narrative, I would advise a climatology textbook. There are some good ones out there — Tate

The article you linked to in no way supports your claim that reglaciation will start in a few centuries.

The article also in no way contradicts the wikipedia statement that we've already delayed reglatiation by some 500 000 years or more.

The article you link to does not even address man-made climate change, but is studying the natural 100 000 year pattern of glaciation and inter-glacials.

The study investigates the mechanisms of glacial retreat in the natural cycle of glaciation.

Which, if humans interfere with the natural cycle, there is zero reason to assume things will continue as normal simply because that's been the pattern so far, just like if we damn a river there is no reason to assume the salmon will return and spawn in the river if the damn physically prevents them from doing so.

The article also in no way contradicts the wikipedia statement that we've already delayed reglatiation by some 500 000 years or more. — boethius

The Wikipedia article is wrong. The same information shows up in the article on the Milankovitch cycle and it's superscripted with "verification failed".

The article I provided does explain that current glaciation cycles are triggered by low summer insolation. That confirms that we are presently near a glaciation trigger. This has been conventional wisdom for several decades.

It means change is ahead no matter what we do. Civilization emerged during a relatively serene period. It's first big test will be whatever happens in the next few centuries. — Tate

The glaciation of the globe, if it occurs, will surely counteract the global warming and if we're lucky and smart enough we may even be able to control the climate by regulating CO₂ emissions. From unmanageable global warming to fine-tuning climate, a plot twist worthy of a bestseller, oui monsieur? I'm not averse to taking some (calculated) risks, mon ami! We can, if we play our cards right, make a good friend of a deadly foe.

From unmanageable global warming to fine-tuning climate, — Agent Smith

That's not what's happening.

That's not what's happening. — Tate

Think before you speak! :chin:

Look before you leap! :chin:

But if you already know, how can I make a choice? — Mr. Anderson

Because you didn't come here to make the choice, you've already made it. You're here to try to understand why you made it. I thought you'd have figured that out by now. — The Oracle

The Wikipedia article is wrong. The same information shows up in the article on the Milankovitch cycle and it's superscripted with "verification failed". — Tate

Maybe cite what you're talking about, but I'm happy to do it for you:

More recent work suggests that orbital variations should gradually increase 65° N summer insolation over the next 25,000 years.[failed verification][failed verification] — Milankovitch cycles - Wikipedia

The statement you cite (I assume ... because you don't actually cite it) that "failed verification" does not contradict the wikipedia statement on the Ice Age page you say it contradicts.

It's a statement that doesn't really infer anything (just "suggesting" something without any predictive value on the whole system; one factor among many, if it is even vaguely representing something true, which "failed verification" may "suggest" it isn't) ... certainly not about events in the next few centuries which is the point under discussion.

Indeed, right after this statement that "fails verification", the same information I cited from the Ice Age page is cited again:

Earth's orbit will become less eccentric for about the next 100,000 years, so changes in this insolation will be dominated by changes in obliquity, and should not decline enough to permit a new glacial period in the next 50,000 years.[38][39] — Milankovitch cycles - Wikipedia

The thing you claim is contradicted ... is literally repeated the very next statement.

What "fails verification" is "recent work" that "suggests" insolation will increase over the next 25 000 years. Now, this could be just a misrepresentation of the work; for example, one subtle orbital mechanic that does increase insolation by itself, in an overall decreasing trend towards less insolation and (without human interference) reglaciation (as we both agree). But we don't know what the source material says ... because it's not cited (honestly seems like someone inserted some propaganda).

Now, what the very next statement in the Milankovitch cycles says, that a new glacial period may start in the next 50 000 years, is true for the Milankovitch cycle, but does not comment on man-made interference, which the Ice Age page provides this additional context with citation (no "failed verification").

Additionally, what matters is the actual sources, not what is tagged or not in Wikipedia. Someone could tag "failed verification" and then the very next day the source is added and the issue resolved.

We need to actual sources.

You are confusing research into the natural glaciations cycles that have been occurring for the last 2 million years with human interference in those natural cycles and the consequences of that.

Again, if humans interfere in a system the pattern may diverge wildly from what was there before. If we damn a river the patterns of fish migration may stop, even if they have been occurring for thousands of years.

If we remove a mountain in mountain top removal operation, it would be clearly wrong to say the mountain will still be there because the patter has been the mountain has been there for millions of years and plate movement is actually pushing the mountain upwards and making it taller. Yes, the natural pattern maybe that the mountain is getting taller and will get even taller due to plate tectonics ... but that theory of the natural system does not remain true if we go and remove said mountain.

The thing you claim is contradicted ... is literally repeated the very next statement. — boethius

It's supposed to follow from the portion that failed verification.

Again, if humans interfere in a system the pattern may diverge wildly from what was there before. If we damn a river the patterns of fish migration may stop, even if they have been occurring for thousands of years. — boethius

Yes. I mentioned the computer modeling on this earlier. I think you're attributing a motive to me that isn't there. This was brought up originally to show that the science of global warming is not simplistic. From there we started debating the standard scientific outlook.

I have not proposed that climate change should be denied due to this information.

It's supposed to follow from the portion that failed verification. — Tate

What failed verification is this:

More recent work suggests that orbital variations should gradually increase 65° N summer insolation over the next 25,000 years.[failed verification][failed verification] — Milankovitch cycles - Wikipedia

Which neither you nor I are claiming.

We both agree that the planet would normally be heading towards reglatiation (I wouldn't say next few centuries, but going towards that).

The issue at hand is the effect of human interference; in particular dumping billions of tons of carbon every year into the atmosphere and carbon cycle that would not otherwise get there, resulting in higher CO2 concentrations in the atmosphere than any point in the last millions of years.

Also nothing relevant can be inferred from this statement about insolation anyways (it does not in any-case comment on the state of the climate system as a whole, which is what we're discussing), even if it was true (which, my guess, is there is some truthiness to it, and it comes from misreading an article discussing some subtle orbital effect that, in itself, increases insolation but is minuscule compared to the major orbital mechanics that will be decreasing overall insolation; and then someone dropped in "aha, insolation will be increasing" without citation ... and so makes sense it fails verification).

The statement that "failed verification" (which in wikipedia is only a tag to represent missing sources, which maybe provided by the author of the statement; it is not a tag that means "this statement is false" and has no argumentative use in that roll), does not remotely do what you are claiming, in contradicting:

In glaciology, ice age implies the presence of extensive ice sheets in both northern and southern hemispheres.[3] By this definition, Earth is currently in an interglacial period—the Holocene. The amount of anthropogenic greenhouse gases emitted into Earth's oceans and atmosphere is predicted to prevent the next glacial period for the next 500,000 years, which otherwise would begin in around 50,000 years, and likely more glacial cycles after. — Ice age

We both agree that the planet would normally be heading towards reglatiation — boethius

Thank you.

The issue at hand is the effect of human interference; in particular dumping billions of tons of carbon every year into the atmosphere and carbon cycle that would not otherwise get there, resulting in higher CO2 concentrations in the atmosphere than any point in the last millions of years. — boethius

Right. That requires computer modeling.

We both agree that the planet would normally be heading towards reglatiation
— boethius

Thank you. — Tate

Where we disagree is that you claim this natural pattern will continue anyways, or there is some serious doubt as to the effect of our CO2 emissions:

For decades now, scientists have known, just from looking at the geological record, that the reglaciation should start sometime in the next few centuries. That means glaciers come back down and cover Chicago. It means the UK is under a sheet of ice. This was disturbing news when it was first discovered, and we now know quite a bit more about how it works, what the trigger is, and so forth.

We don't presently know if increased CO2 will cause us to miss the trigger, or if reglaciation will begin anyway. There are aspects of the question that we don't even know how to model right now.

No, it's not simple. — Tate

We not only know that our current CO2 emissions will delay reglaciation by upwards of 500 000 years or more, but we also know that CO2 emissions are pushing us out of the current climate paradigm altogether, towards an ice-free planet.

There are always more details that can be modelled, no predictive model is as complete as the natural system being modelled (this is true for all models).

What matters is the confidence of the predictions that can be made with current knowledge and modelling, and then risk assessment.

The risks are intolerably high ... which you seem to agree with.

It would probably be prudent to put the brakes on CO2 emissions, like completely. — Tate

So, it's not clear what you're even disagreeing with or what point you are trying to make. If you want to just discuss the physics of the climate and get into nuances that have no relevance to this particular discussion, then there are science and physics forums for that.

You seem to just want to make vague statements that imply global warming is not a problem, might get magically solved, or scientists "don't know everything", to soften the blow, such as we're going towards an ice age in the next few centuries (sounds the opposite of warming! god be praised!), but then just backtrack everything to actually have been completely meaningless and irrelevant to the topic at hand.

That's not good faith discussion and deserves no respect.

Where you do make statements that have a baring on the discussion, such as "We don't presently know if increased CO2 will cause us to miss the trigger, or if reglaciation will begin anyway," they are simply false.

You seem to just want to make vague statements that imply global warming is not a problem, — boethius

That's just not true. I've explained that several times now

That's just not true. I've explained that several times now — Tate

That's what you're statements, like an ice age is expected in the next few hundred years, imply.

Your whole current argument is that there is some doubt as to the next ice age, that human CO2 has not completely disrupted the natural cycle, or then there is some doubt about that. Read your own statements.

Obviously, if the earth may actually cool anyways and the current warming is transitory, that implies global warming is a lot smaller problem than essentially the entire climatology community have concluded.

Essentially all your statements, either about the ice age, or claiming gaps in knowledge (which only matter in the context of this discussion if the uncertainty would change a decision, of which there are no candidates), such as

There are aspects of the question that we don't even know how to model right now.

No, it's not simple. — Tate

Or take your statement:

We are in an ice age guys. Get yourself up to speed. — Tate

What other interpretation of this statement is possible than implying interlocutors discussing the catastrophic consequences of climate change do not know we are "in an ice age" which has the connotation of being cold rather than hot.

Likewise, by being derogatory in this matter, that participants do not have an even basic knowledge of the subject (while predicting an ice age will likely, or even potentially, start in a few centuries), that their statements can therefore be dismissed.

That's what you're statements, like an ice age is expected in the next few hundred years, imply. — boethius

I don't think we should back down from stating scientific facts because someone could imply something we disagree with.

I don't think we should back down from stating scientific facts because someone could imply something we disagree with. — Tate

As has been explained to you in your thread complaining about the moderation, throwing out a scientific fact that has no relevance to the discussion (neither supporting nor contradicting any position in the discussion, not even your own, which seems to be we should stop all CO2 emissions immediately), is bad faith and adds nothing to the dialogue.

Almost none of your statements are scientific fact, and, this particular example of an ice age starting in a few hundred years, has zero scientific basis whatsoever and is extreme contradiction to what the entire climatology community is predicting.

So, first, in no way factual and you've provided no citations to support your mad theory that an ice age is likely, or even remotely possible, to be triggered in the next few hundred years. So, if you want to play the facts game, which I suggest you do, then the basic rule of the game is "evidence", which you provide nothing remotely supporting your claims.

You're intention is clear: try to throw out statements that make one implication, or just false statements, then ignore criticism or backtrack to your statement being totally meaningless.

For example, that models are not complete is true for all models. To be relevant to the discussion you need to point out what's missing from those models and what decisions might change in a more complete model and how that change is relevant.

However, for climate models, there are no such candidates.

Increasing CO2 beyond anything the earth has experienced in millions of years is a reckless uncontrolled experiment with intolerable risks, already intolerable proven harms to people and living systems we've caused so far, and more precise models have zero candidates of greater precision or then added complexity that would remotely possibly change such a conclusion.

Throwing shade on the models by claiming they aren't complete (as is true for all models) has no relevance to any decision making.

It's called propaganda, not good faith discussion. If you genuinely perceive yourself as not repeating propaganda, then you're a useful idiot to the propagandists that have filled your head with nonsense.

Almost none of your statements are scientific fact, — boethius

That's really not true. I'm not continuing this discussion with you.

That's really not true. I'm not continuing this discussion with you. — Tate

Most of your statements are not even purporting to be facts, and the one's that are you do not support with any evidence, and the one statement you cited an article for does not support your statement.