Who is right? The climate alarmists? Or the Climate deniers?

Who said there was only one possible result of a tipping point?

 

The point is that the claimed high-CO2 "tipping points" -- conditions where positive feedback takes over -- do not exist, as the claimed possible results have never occurred at any previous higher level of temperature or CO2. The only known real tipping point is to the downside, is associated with the ice albedo feedback, and has given us the ice ages.

 

Yes! That’s why I’m explaining to you WHY higher CO2 levels result in a more comfortable life for humans. It enhances plant growth for agriculture and general greening of the planet. It also warms the planet which results in decreased net human mortality related to suboptimal temperature.

We know these things because of evidence produced through application of the scientific method. We know WHY increased CO2 and temp impact plants and the way they do based on genotype and phenotype resulting from selective pressures from the past. That’s why what happened in the past matters. It helps up understand WHY increased CO2 aids plant growth and WHY increasing temps decreases net mortality related to suboptimal temperatures.

 

No. The issue is that there’s no CO2 tipping point. If you claim that there is - what concentration?

 

Ridiculous but okay - What are these multiple tipping points.

 

It seems people who go on about tipping points etc. don’t understand cycles and feedback loops.

For example. They don’t account for plants sequestering carbon at higher rates as atmospheric CO2 levels increase.

They hear a warmer planet may result in some areas having longer periods with low or no precipitation. But they don’t account for plants becoming more efficient in water use at higher CO2 concentrations.

They hear a news story about dangerous wet bulb temperatures that are a function of temperature and relative humidity. They get scared because of higher temps with AGW but are completely unaware global terrestrial relative humidity is falling, thus cancelling out the effects of increased temperatures on wet bulb scenarios.

A couple days ago I had a guy complaining about increased extreme precipitation events and concern about depletion of unconfined aquifers. Of course he was completely unaware recharge of unconfined aquifers is greatly accelerated by “extreme” precipitation events.

What it boils down to is folks have been greatly misled. When media talks about temperature related deaths they only mention heat related deaths that are 10 times less than cold related deaths. When media talks about extreme precipitation events they only report on flooded basements or some other negative aspect. They never report on events like we recently had here where an “extreme” rain event added millions of dollars to the economy, decreased fossil fuel usage, suppressed fire danger, and replenished the aquifer. And it didn’t “hurt” anything.

When crops are discussed by media, only studies that don’t account for adaption are cited. This makes the erroneous assumption that as growing seasons lengthen, producers won’t plant earlier and choose varieties and hybrids that thrive with a longer season. They never report on peer reviewed studies that show higher yield potential with warming.

In short, folks have been led to believe ALL results of increased atmospheric CO2 are bad and that all results of warming are bad. Nothing could be farther from the truth. But people are misled by being fed only a small part of the data. Thus their perception of reality is not in line with reality. This means “tipping points” are accepted because the one accepting them is operating from a false premise based on incomplete information.

 

I pointed out the methane from tundra back in post #2109. The CO2 affects the temperature which affects the tundra which releases methane which is a more powerful greenhouse gas than CO2.

So there is the possibility of getting to a point where CO2 doesn't matter because there is too much methane. It is like some people cannot handle multiple interacting variables.

 

Actually, at one time the planet was very much like Venus. With an extremely high atmospheric pressure, temperatures, and a haze that covered the globe.

And many now believe that the water that accumulated on our surface and the life that evolved there is why we are no longer like that. But Earth in the Hadean Eon was not all that unlike what Venus is like today.

 

Oh, we have some good guesses about that. Most think it was for around 10 to 50 million years, and then another 25 to 30 million years the second time after Theia. The first life on our planet was around 3.7 billion years ago, but the first cyanobacteria were around 2.5 billion years ago. Which was shortly before the Great Oxidation Event of roughly 2.4 billion years ago.

 

How long do you think it will take to melt the tundra and release all this methane?

 

Interesting. I didn’t know that. But of course iincreasing atmospheric CO2 wasn’t the driver.

 

How confident are you that permafrost will release massive amounts of methane?

 

Which is actually backwards. One can see that clearly if they live in California for a few years, then in Southern Alabama.

In the summer, both actually have roughly the same temperature range. However, where one averages at around 35% humidity, the other averages into the 80% range. And where one will spend months with no precipitation at all, the other will get most of their largest storms and downpours in the summer. On average in Alabama, it will rain 3 or 4 days a week in the summer. And where in the Western states "Swamp Coolers" are common to add humidity to a house to make it cooler, in the SE the exact opposite is done and humidity is removed from the air.

From what I have read, most of the areas that will get less precipitation will be the inland areas, especially those in rain shadows. It is hard to predict future weather patterns, but moisture is theorized to become more affected by coastal basins and accumulate in those areas (not unlike a rainforest effect), and be less likely to move inland. But to compensate globally, all those coastal areas would become more lush.

We know that in the past, much of the West Coast of the US was a rainforest. The Redwoods of California now exist in a small range of temperate rainforest. But at one time they stretched up and down the Pacific Coast form Northern Mexico to Canada, as far inland as Montana and Wyoming, Texas, and up the East Coast to Pennsylvania. And in Eurasia from England and Germany into modern Kazakhstan. Which means at one point, all of those regions had a climate somewhat similar to Northern Coastal California today.

 

<sigh> So why didn't that happen on any of the dozens, hundreds, or even thousands of previous occasions when CO2 and/or temperature increased to more than the current level....?

Blank out.

 

Well, the atmosphere of the early planet was very different. To start with, it was actually high in both methane and carbon dioxide. And the average temperature was over 260c (450f), and estimated to be at around 27 atmosphere of pressure As I said, not unlike conditions on Venus today.

But Venus is not really a "runaway greenhouse effect" like many claim, it has always been that way. Our own planet simply evolved out of one thanks to abundant water and changing of the composition of the surface to become something else. Without large oceans and eventually life, Venus never evolved away from those conditions. And no matter how bad a "greenhouse effect" our planet might ever fall under, it will come nothing even close to that because there is no way short of something like a planetary collision that could return us to those kinds of atmospheric pressures. Because much of the heat of Venus is a result of that pressure and not actual CO2.

I simply have a fascination with documentaries of our planet. Especially of ones that cover geology, ranging from the Hadean and even through the "Boring Billion" to more modern eras. And in watching and studying things like this one can see the changes our planet has gone through, and the many wide changes in our climate and atmosphere.



This really is a case where one can not understand the current and future era without knowing the past.

 

Because that is happening right now, and has always happened.

Permafrost is primarily frozen mats of huge amounts of plant matter, where all decomposition ended when it became frozen. And what first grew on the plains that the glaciers scraped clean was mostly lichens then moss. That had lifespans normally of a single year, died when frozen again come winter, then the next generation grew on top of. A cycle repeated for thousands of years with no real time for decomposition. Piling up until it reaches a depth of one to 1,000 meters.

And at one time, our Great Plains was permafrost. A hundred meters or more in depth, that as the last ice age ended was similar to what is found in Alaska and Central Canada today. But eventually over thousands of years melted, decomposed, then when it no longer froze annually transitioned to the fertile grasslands we have today. The entire region of highly fertile soil from the Central US to much of Canada was permafrost about 10 kya. But without the mile thick glaciation and warmer temperatures all the plant matter eventually decomposed and became fertile grasslands.

But those millions of tons of frozen dead plant matter will eventually decompose when it no longer freezes regularly for months at a time. And the microbes that decompose it will release huge amounts of methane as part of the process. It is simply science.

 

The only possible "tipping point" that could cause Earth to return to an atmosphere like Venus would be massive vulcanization. To spew out so much so much gas that it would increase the pressure of the planet a thousand fold, and cause mass extinctions of all life short of the extremophiles.

 

It seems we have overestimated the methane released from permafrost. We failed to account for natures solutions. When we actually measure instead of guess we are finding MUCH less methane is released than was predicted.

https://phys.org/news/2022-05-northern-sweden-methane-emission.html

 

Oh, several thousand years.

It is estimated that the transition from permafrost and tundra to the Great Plains we have today took around 5,000-6,000 years. First the region had to stop freezing annually so decomposition could occur. Then decomposition to change the mats of permafrost and tundra into fertile soil that would support a wet bog like condition that existed for another couple of thousand years. And only then could it dry up and evolve into the grasses of today. Which following ecological transitions might eventually have given way to forests if conditions evolved to that degree.

One can even see that in the megafauna extinctions of the past 15,000 years. As first the animals that survived on permafrost and tundra ecosystems died off, then those evolved to survive in wetland bogs died out. Leaving only those that could survive in a grasslands environment. That is why the mammoth went extinct, it evolved to survive on the early grasslands that existed in the transition range between the permafrost and grasslands. Mastadons lived in a similar ecological niche, primarily surviving in coniferous temperate rainforest like conditions like seen in NW Washington today. But which at one time extended down into what is now Central Mexico.

And that may be extended, as in the past during the Iron Age Cold Epoch or the Little Ice Age. Where conditions changed to once again allow "glaciation" to expand, but not to the degree where they started to massively move and scrape the surface clean. Where once that ended the cycle would repeat and allow even thicker layers of permafrost to accumulate once the conditions allow.

 

Oh, it likely did.

But at best it is only a guess to determine what the conditions were like past a couple of thousand years ago. The most we can use to determine that is ice cores and mud cores from the ocean. And that rarely gives an actual "true number", but for an example an estimation based on what dead microscopic animals are found in the mud cores. They can not look at a mud core and say "Hey, it was XX degrees with YY levels of CO2", but look at what animals there are trapped in it and speculate what the conditions were based on which ones are found.

Then having to guestimate what the ocean currents were like, as that has a great effect also. If the Atlantic Current was for some reason to reverse, then the dead plankton in the cores off of North America will then look like those off of Europe, and the reverse of their cores looking like ours.

But there is no "magic bullet" that can peel back the layers 100 ky or more and get an exact answer. They can only speculate based on what evidence we can find. And realizing that for much of that evidence, it simply does not exist. For example, multiple glaciations and volcanic events in North America has either scraped such evidence clean, or buried it under miles of basalt.

 

And how thick was the permafrost and how long did it build up?

Sweden is rather unique, like much of Scandinavia as their permafrost is "newer" and much less thick than the permafrost in much of Asia and North America. In Scandinavia, the ice sheet melted only around 14,000 years ago and froze often enough that it did not have the tundra and permafrost buildup to the same degree as Central Canada.

 

Yes. Higher temperatures means more water evaporation and more precipitation. Warmer means wetter not drier.

 

Exactly.

 

When did I ever bring up VENUS?

I presume that cannot possibly happen to the Earth because there is too much water. More water is evaporating into the atmosphere now and precipitates somewhere .

 

I swear, I just saw this a few minutes ago.



But anybody who has actually paying attention wouldvhave heard about it years ago.