Are most climate scientists alarmists?

[drumbo]

Most climate scientists claim that elevated CO2 levels will be devastating to Earth's ecosystems. However when CO2 levels were highest some of the largest terrestrial organisms were alive, such as dinosaurs, giant turtles, etc. There must have been an abundance of caloric resources in order for such large organisms to sustain themselves. How can we claim that elevated CO2 levels and higher temperatures will lead to the collapse of ecosystems, when under those very conditions the most demanding organisms in terms of caloric requirements were able to thrive? Based on historical evidence it seems like ecosystems would be more vibrant when CO2 levels and temperatures are higher.

[John Cuthber]

Are most climate scientists alarmists?

No

The problem is the rate of change of CO2 and thus of climate.

[timo]

In my experience, the concerns about climate change are the impact on human civilization over the next few hundred years. Not the impact on biological systems over thousands/millions of years. The whole climate change concern issue is a selfish, short-sighted thing of the humies, completely disregarding how great it could be for dinosaurs and turtles in the long run.

 

[joigus]

On 2/13/2020 at 5:57 AM, drumbo said:

How can we claim that elevated CO2 levels and higher temperatures will lead to the collapse of ecosystems, when under those very conditions the most demanding organisms in terms of caloric requirements were able to thrive?

I understand how you can say that. But it's not that clear to me. First, dinosaurs, like any other megafauna, are almost anecdotal in terms of primary production, carbon cycle, etc. To give you an example, there are about ten trillion tons of methane stored in the oceanic bottoms that can't get out thanks to methane-metabolizing microscopic archaeas that are keeping it at bay. And, mind you, methane is 25 times more greenhouse-effect inducing than CO₂ is. If you want to understand ecosystems you must look at microorganisms. They don't look as pretty in a theme park, but are far more important for the global chemistry.

Another question is the rate at which this is happening. Back in the time of the dinosaurs the conditions were quite stable, and many big animals (quite a big bunch of them in terms of animal biomass) may have been slow-metabolism. As to the dinosaurs, we don't really know if they were or how many there were. We do know that all the plants were C3, because C4 plants did not exist. How did that affect the carbon cycle? Be aware, e.g. that RubisCO, the carbon-fixating molecule, is the most abundant organic molecule on Earth by far.

In fact, C4 plants, which are more efficient at sucking up CO₂ from the atmosphere, precisely evolved to adapt to the new, slowly-changing, low-CO₂ atmospheric conditions. And that's the observation that leads me back to the question of rate. Organisms need time to adapt, measured in tens of millions of years, not decades, for those paradises that you picture in your mind to establish themselves.

We are now pumping into the atmosphere an estimated billion tons of CO₂ per year. The Earth is 100 years within a Milankovitch cycle of glaciation, and yet the glaciers are clearly melting, and fast. We are really fortunate that the Himalayas are still pushing up, because this geological process sucks CO₂ from the atmosphere at an incredible rate, and sends it back to the sea.

The really big question now is what will happen when the ice sheet on Greenland sloshes down to the North Atlantic, as it is sure that the salinity will go down significantly and the conveyor belt that equilibrates the water temperature will eventually stop. It is estimated that that will happen by 100 years' time. Have you thought in any depth about these and other factors?

Edited May 6, 2020 by joigus
mistyped

[studiot]

39 minutes ago, joigus said:

We are really fortunate that the Himalayas are still pushing up, because this geological process sucks CO₂ from the atmosphere at an incredible rate, and sends it back to the sea.

Thank you for this potted essay, it is really good and introduces several things that were new to me. +1

However I would appreciate more information on why you think the Himalaya removes much carbon dioxide, given this description of the principal rock types

Quote

Metamorphic rocks present in the Himalayas include schist, migmatite, phyllite, gneiss and amphibolite. Additionally, metamorphosed forms of some sedimentary rocks occur in the region, such as quartzite, a metamorphosed type of sandstone; slate, a metamorphosed form of shale; and marble, a metamorphosed limestone.

There are some carbonate rocks in the Himalaya, but much has already been metamorphosed.

https://mynepaltrek.com/rock-types-in-nepal/

[Area54]

10 minutes ago, studiot said:

Thank you for this potted essay, it is really good and introduces several things that were new to me. +1

However I would appreciate more information on why you think the Himalaya removes much carbon dioxide, given this description of the principal rock types

There are some carbonate rocks in the Himalaya, but much has already been metamorphosed.

https://mynepaltrek.com/rock-types-in-nepal/

The majority of the rocks you mention are composed predominantly of silicate minerals. These are weathered by carbonic acid, converting for the most part to clays,  with a portion of the carbon dioxide now "trapped" as calcium carbonate. Unfortunately, the amount of CO2 removed by weathering globally is an order of magnitude less than the amount being released by human activity. The weathering/ocean sink is important for the long term carbon cycle, but does little to help us with the rapidity of change we have introduced.

This is a basic summary of the factors involved.

I agree with you, it was an excellent post by joigus .

[joigus]

17 minutes ago, studiot said:

However I would appreciate more information on why you think the Himalaya removes much carbon dioxide, given this description of the principal rock types

I was quasi-quoting Dan Britt in Orbits and Ice Ages: The History of Climate. Conference you can watch on Youtube.

You got me: argument of authority, I should be ashamed of. Conversations with you are starting to get very stimulating. Thank you very much for the references. I'll reconnect in about 5+ hours, then learn geology in about a couple of hours, and then keep talking with you, hopefully.

The bio-data I got mostly from https://www.amazon.com/Life-Science-William-K-Purves/dp/0716798565 and a wonderful MIT course by Penny Chisholm.

[studiot]

1 hour ago, Area54 said:

The majority of the rocks you mention are composed predominantly of silicate minerals

And buried in the link you posted is the following

 

Quote

It is important here to point out that weathering of silicates containing e.g. only potassium or sodium does not trap carbon in the same way, because the carbonates of these elements are water-soluble so they do not precipitate to form sediments. Calcium and magnesium are the key.

 

So what % of the silicates are calcium or magnesium silicates?

[dimreepr]

On 2/13/2020 at 4:57 AM, drumbo said:

Most climate scientists claim that elevated CO2 levels will be devastating to Earth's ecosystems. However when CO2 levels were highest some of the largest terrestrial organisms were alive, such as dinosaurs, giant turtles, etc. There must have been an abundance of caloric resources in order for such large organisms to sustain themselves. How can we claim that elevated CO2 levels and higher temperatures will lead to the collapse of ecosystems, when under those very conditions the most demanding organisms in terms of caloric requirements were able to thrive? Based on historical evidence it seems like ecosystems would be more vibrant when CO2 levels and temperatures are higher.

I'm guessing they're alarmed, because we're not dinosaurs; and like the dinosaurs, life will continue after the planet chooses to no longer sustain us.

[studiot]

1 hour ago, joigus said:

The bio-data I got mostly from https://www.amazon.com/Life-Science-William-K-Purves/dp/0716798565 and a wonderful MIT course by Penny Chisholm.

Thanks for the extra info. You are way ahead of me in the biosciences. +1

Joigus and Area54

As to authorities, it is well known that I favour books over internet articles, here is one by the Professor of Paleoclimatology at Sheffield University.

David Beerling The Emerald Planet.

It is the only history of the atmosphere I know of.

[Area54]

5 minutes ago, studiot said:

So what % of the silicates are calcium or magnesium silicates?

A good question. I shall trawl through some textbooks, but the simple qualitative answer is - a substantial amount.

A more nuanced answer would be to note the following:

Major silicate minerals fall into the following groups:

Ortho-silicates: these include the olivine group minerals, in which the eponymous mineral is a solid solution of Fe silicate and Mg silicate. It is a major mineral in basic lavas, including basalt, the commonest lava on (and off) the planet. The ortho-silicates also include several common metamorphic minerals, such as garnet and staurolite, which contain calcium or magnesium as principal elements.

Chain Silicates: These, especially the pyroxenes and amphiboles, are major minerals in both igneous and metamorphic rocks. There are many varieties, but magnesium is common in such minerals as the pyroxenes enstatite and hypersthene, and the amphiboles hornblende and glaucophane. Calcium is abundant in the pyroxenes pigeonite, augite and wollastonite. (The latter is CaSiO₃). There are many more examples, but the ones mentioned are all important rock forming minerals.

Sheet Silicates: Serpentine and chlorite are important metamorphic minerals rich in Mg. (Mg is the only metallic element present in chlorite.) Biotite, one of the two common micas, contains significant Mg. The clay minerals are exceptionally varied, but most varieties include Mg, or Ca, or both in their structures and are thus abundant in many sedimentary rocks.

Framework Silicates: Of relevance here are the hugely important feldspars, in particular the plagioclase group. These contain Na and Ca as the dominant metallic ions. Mg is present in lesser amounts in some feldspars.

So, you see that the major minerals, incorporating significant amounts of Ca, or Mg, or both are to be found in all major rock groupings, igneous, metamorphic and sedimentary.

I recommend An Introduction to Rock Forming Minerals, by Deer, Howie and Zussman for anyone looking for something more on minerals. This is the classic on mineralogy. I think the latest edition came out in the early 90s, but I used my 1966 1st edition to check that my memory wasn't too far adrift on the brief notes above.

On a separate point, re-atmosphere history, Chemistry of Atmospheres, by Richard P. Wayne Oxford University Press 1991, contains a chapter on atmosphere evolution. I've found it useful.

 

Drat. I am not thinking logically. What you are actually asking is the proportion of Ca and Mg in the crust. That is readily available, as in this Wikipedia article.

It give Ca as 4.15% and Mg as 2.33%, making them the 5th and 7th commonest elements in the crust. Those percentages may seem low, but keep in mind that almost 75% of the crust is composed of silicon and oxygen.

[studiot]

1 hour ago, Area54 said:

Drat. I am not thinking logically. What you are actually asking is the proportion of Ca and Mg in the crust. That is readily available, as in this Wikipedia article.

 

Not quite

I was actually asking what is proportion of calcium and magnesium in the upper rocks of the Himalaya ?

I would imagine this is quite different from the upper rocks in say the Sahara.

Edited May 6, 2020 by studiot

[MigL]

Interesting discussion about rocks...

I would say that quite a few climate scientists are alarmist.
Then again, most feel they have to be, as a large portion of the population refuses to believe, much less understand, the science.

[Area54]

58 minutes ago, studiot said:

 

Not quite

I was actually asking what is proportion of calcium and magnesium in the upper rocks of the Himalaya ?

I would imagine this is quite different from the upper rocks in say the Sahara.

I strongly suspect that is not going to be the case in manner which is significant for this discussion. The Himalaya are, as you know, vast and contain a wide - and typical - variety of rock types. Their elevation and associated deep levels of erosion expose that range of rocks. I would be surprised if the deviation was significant. Certainly, the variation could not possibly be sufficient to make a meaningful dent in the CO₂ released by human activity annually, which I understand is the point you are focusing on. Or, were you heading in another directIon?

1 hour ago, MigL said:

Interesting discussion about rocks...

I would say that quite a few climate scientists are alarmist.
Then again, most feel they have to be, as a large portion of the population refuses to believe, much less understand, the science.

I think the climate change situation is alarming. What makes it more alarming is the refusal that you note by much of the public (and interested corporate bodies) to believe there is a problem. In that setting sober, documented and justified estimates of climate change and its consequences can be seen as alarmist by those who refuse to accept that there is a significant risk. "Alarmist" then becomes a rhetorical catchphrase used to excuse acceptance of the evidence.

On the plus side, evolution may one day produce an animal that is not only as intelligent as homo sapiens, but is actually able to use that intelligence in a consistent and organised way.

[studiot]

1 hour ago, Area54 said:

I strongly suspect that is not going to be the case in manner which is significant for this discussion. The Himalaya are, as you know, vast and contain a wide - and typical - variety of rock types. Their elevation and associated deep levels of erosion expose that range of rocks. I would be surprised if the deviation was significant. Certainly, the variation could not possibly be sufficient to make a meaningful dent in the CO₂ released by human activity annually, which I understand is the point you are focusing on. Or, were you heading in another directIon?

No, I am trying to discuss and dissect rationally the proposition that the Himalaya is a good example of carbon 'fixing' by geological processes.

1) The Himalaya is a very recent geological structure, thrown up by the impact of the indian plate into the asian plate. This was accompanied by substantial vulcanicity, which will have released much geologicallly held carbon dioxide. The vulcanicity also metamorphosed many of the rocks involved which will have reduced their susceptibility to chemical solution weathering, which is the process that sequesters carbon dioxide.

2) The impact was sufficiently violent to throw up the currently largest mountains in the world. So high that they have a near permanent snow cover. At such low temperatures any chemical activity will be considerably slowed.

3) There are still some limestone and dolomite layers left intact. These will obviously be the most susceptible to this type of weathering. But they are a small % of the total rocks exposed or within the depths reached by percolating acid groundwater.

4) I posted a link recently of a Chinese study in the limestone foothills where they discovered underground lakes actually sequestering above average carbonate stores. (I will try to find that again)

5) Carbon dioxide concentration reduces with altitude

Quote

https://www.co2meter.com/blogs/news/127454855-altitude-compensation-for-co2-sensor-modules

Here at CO2Meter, our rule of thumb is that the CO2 level at altitude will change about 3% for every 1,000 feet (300m). At 5,000 feet, that would be 400ppm less 15%, or about 340ppm.

So at 25000 ft the CO₂ % will reduce by 25 * 3 = 75%

Edited May 6, 2020 by studiot

[MigL]

1 hour ago, Area54 said:

think the climate change situation is alarming.

I suppose 'alarmist' can be taken two ways...

The 'Chicken Little - the sky is falling' interpretation leads a few people ( even some scientists ) to say things like "runaway climate change will lead to the Earth becoming like Venus, with pools of molten lead, and sulfuric acid rain".
A Physical impossibility, that makes some people wonder what the he*l those few are thinking.

The other way to interpret 'alarmist' is simply as someone issuing a warning ( sounding the alarm, if you will ) of possibly dire consequences, if we continue on the same path. That would be the majority of climate scientists.

Edited May 6, 2020 by MigL

[Strange]

Are fire alarms "alarmist"?

[joigus]

1 hour ago, Area54 said:

I strongly suspect that is not going to be the case in manner which is significant for this discussion. The Himalaya are, as you know, vast and contain a wide - and typical - variety of rock types. Their elevation and associated deep levels of erosion expose that range of rocks. I would be surprised if the deviation was significant. Certainly, the variation could not possibly be sufficient to make a meaningful dent in the CO₂ released by human activity annually, which I understand is the point you are focusing on. Or, were you heading in another directIon?

This very much converges with what I was thinking --even being an absolute nuthead when it comes to geology. The Himalayas are very much geologically active. They are very "plastic," so to speak. Erosion is at its maximum Earth-wise (you just have to take a look at the Kali Gandaki gorge.) I'm sure swathes of relatively young or "uncooked", sedimentary, non-metamorphic rock are being exposed too. But I must confess I'm not sure by any means...

Eons of rock formation are being stripped away there. What do you guys think?

[Ken Fabian]

It may not be intended that way but "alarmists" usually means people making exaggerated or false claims of impending doom. Being alarmed because multiple (independent) studies all show we face a real problem of unprecedented scale is not the same as being "alarmist".

That aside, the impacts of current warming are expected to harm people now living in ways that look ongoing and irreversible; our responsibilities to "the planet" or it's remnant natural ecosystems may be unclear and not universally accepted but our responsibility to people generally is. I am one who think we do have that broader responsibility - and that issues like climate stability and unsustainable land use practices are inextricably linked to enduring human prosperity and security.

It doesn't matter what the CO2 levels and global temperatures were millions of years ago or how much life (but not humans) thrived under those conditions -  the life and lives of humans now living would be ruined by a return of similar conditions.

[StringJunky]

21 minutes ago, Ken Fabian said:

It may not be intended that way but "alarmists" usually means people making exaggerated or false claims of impending doom. Being alarmed because multiple (independent) studies all show we face a real problem of unprecedented scale is not the same as being "alarmist".

That aside, the impacts of current warming are expected to harm people now living in ways that look ongoing and irreversible; our responsibilities to "the planet" or it's remnant natural ecosystems may be unclear and not universally accepted but our responsibility to people generally is. I am one who think we do have that broader responsibility - and that issues like climate stability and unsustainable land use practices are inextricably linked to enduring human prosperity and security.

It doesn't matter what the CO2 levels and global temperatures were millions of years ago or how much life (but not humans) thrived under those conditions -  the life and lives of humans now living would be ruined by a return of similar conditions.

"Alarmist" is used by people who don't believe a threat is real; with dismissive connotations.

Edited May 6, 2020 by StringJunky

[MigL]

That interpretation is in the 'ear of the listener'.
An alarmist, by definition, sounds, or voices, an alarm.

Humans have a bad habit of changing definitions to suit their purposes/agendas.
You need to consider the source using the term, to deduce the agenda of that source.
I certainly wouldn't be offended at being called an 'alarmist' for pulling the fire alarm in a burning building.

[StringJunky]

4 minutes ago, MigL said:

That interpretation is in the 'ear of the listener'.
An alarmist, by definition, sounds, or voices, an alarm.

Humans have a bad habit of changing definitions to suit their purposes/agendas.
You need to consider the source using the term, to deduce the agenda of that source.
I certainly wouldn't be offended at being called an 'alarmist' for pulling the fire alarm in a burning building.

One needs to consider modern usage rather than vanilla definitions. See what I did there?

Edited May 6, 2020 by StringJunky

[MigL]

Yeah, but I can't keep up with 'modern' usage.
It changes way too quick  .

Apparently I'm out of bed, showered, shaved and dressed, but I'm not 'woke' yet.

Edited May 6, 2020 by MigL

[Ken Fabian]

23 hours ago, StringJunky said:

"Alarmist" is used by people who don't believe a threat is real; with dismissive connotations.

Used that way, yes, but falsely about people taking decades of consistent top level expert advice - alarm calls - seriously; sounding an alarm when the threat is real is not "alarmist". Climate scientists expressing alarm are not "alarmists".

According to dictionaries it is variants of "someone who exaggerates a danger and so causes needless worry or panic."

23 hours ago, MigL said:

That interpretation is in the 'ear of the listener'.
An alarmist, by definition, sounds, or voices, an alarm.

MigL - I think the meaning is clear and has remained unchanged (other than by misuse) over time; the changing of definitions that alarms me is using it to denote a political extremist irrespective of whether there is real cause or not to raise an alarm.

Edited May 7, 2020 by Ken Fabian

[StringJunky]

9 minutes ago, Ken Fabian said:

Used that way, yes, but falsely about people taking decades of consistent top level expert advice - alarm calls - seriously; sounding an alarm when the threat is real is not "alarmist".

According to dictionaries it is variants of "someone who exaggerates a danger and so causes needless worry or panic."

MigL - I think the meaning is clear and has remained unchanged (other than by misuse) over time; the changing of definitions that alarms me is using it to denote a political extremist irrespective of whether there is real cause or not to raise an alarm.

This is my take. I have never seen the word applied literally. It is always used currently from a perspective of criticism. Definitions are fluid through time and it's the contemporary use that is relevant.

Edited May 7, 2020 by StringJunky