Climate change

[Serpent]

We have some agreement on that point:
https://www.theatlantic.com/ideas/archive/2019/09/greta-thunbergs-despair-is-entirely-warranted/598492/
She's not emotional.* Doesn't know how. She's pragmatic.
https://www.vox.com/2019/9/17/20864740/greta-thunberg-youth-climate-strike-fridays-future
But all the other kids who don't want us burning up their world are plenty emotional.


(*She's had plenty of 'emotion' directed at her by the 'skeptics', as well.
https://www.themarysue.com/greta-thunberg-harassment-online/
I know that's not everyone's first choice of an information source, but it's a mouth of the young horse from whom we don't often hear - and to whom we don't listen enough.**)
(**We have an excellent reason for ignoring them. They have no $$$$)

[TheVat]

Yes, Thunberg's high-functioning autism seems to be a cognitive style that actually helps her to be an uncommonly calm and poised 16 year old.

As that precocious Swede understands, unreasoning fear is the emotion people need to get past, so they can plan constructive action.


https://www.bbc.com/news/science-environment-49773869

(This references the WMO report on data of the five year period, 2014-19, and evidence for the acceleration I mentioned a couple posts back)

[doogles]

My problem with the problem is the poor science,

By what standard is the prevailing climate science "poor"?

the lack of consensus

https://climate.nasa.gov/scientific-consensus/
https://skepticalscience.com/global-warming-scientific-consensus-intermediate.htm
Really? I suppose, as long as somebody with a doctorate can be found to counter-blog, it's not a 100%; therefore, leaves plenty of room for doubt and forces you to collect raw data and create you own model. It's something to do while waiting.

and the emotionalism associated with the whole climate change story. This Arctic/polar bear/climate change is a good example.

Is, in fact, the only example. That's why the deniers are picking on the polar bears - they're more photogenic than lobsters, etc., so they've become a symbol. Meanwhile, thousands of species are going extinct without so much as an obituary. It will get much worse very fast.
https://www.scientificamerican.com/article/mass-extinction-in-earth-rsquo-s-oceans-could-begin-by-2100/
The world is ending. We're all going to die. Nothing to get excited about.

Thanks again Serpent and for the comments.

I read those two references Serpent. You would have noticed that all of those organisations state consensus on the belief that average near surface temperatures are rising and that human activities are probably to blame. You also would have noted that I agree with that. In my last post I said "Yes, there is an increase in average near surface global temperatures, most probably caused by human activities, and there are many observable probable geophysical changes as a result." We do have consensus up to that point. One or two included greenhouse gas emissions as part of their statements; most didn't. I don't know whether that was deliberate or whether it was an omission, but I'll mention emissions later.

Some use the emotional term 'global warming'.

The original coinage of the emotional term 'global warming' was made Hansen in his original paper on average global near-surface temperatures (AGNST). The term has connotations of spontaneous combustion of the sphere we inhabit. I consider it to be unscientific because of its emotional connotations, and I naturally become suspicious of the scientific integrity of the work associated with its use. You may be aware that James Hansen based his initial conclusions on changes in temperature recordings at weather stations all over the globe, without checking on the history of those stations -- changes of location, changes of recording devices and erections of buildings around existing stations. It took a weatherman named Anthony Watts and hundreds of volunteers to establish that Hansen had made too many assumptions -- which is bad science -- when he published his first findings. It resulted in large corrections of initial data, and resulted in a significant reduction of the claimed 'global warming'. It was bad science.

Hansen also just stated that carbon dioxide was the cause of that 'global warming' (ugh) even though, in the same paper, he mentioned the fact that between 1940 and 1970, the AGNSTs had dropped 0.5 degrees C in spite of large increases of carbon dioxide.

I consider that poor science.

Not only that, but all of the theory of greenhouse gas effects is based on the work of John Tyndall performed with crude equipment in the 1860s. I've searched and asked other members of the forum to help me find where any modern work has been performed on the properties of absorption and radiation of infrared radiation by carbon dioxide. The reason I would like to see this work performed is because there are two schools of thought about carbon dioxide. The assumption appears to have been made that absorption is linear -- that is, that the more carbon dioxide in the atmosphere, the more heat energy it will absorb and hold for a while. But another school of thought, led by a climate scientist named Idso (who is reputed to have published something like 500 papers and books) is that absorption is logarithmic -- that is, that most of the absorption is performed by the lower concentrations of carbon dioxide and that larger concentrations do not absorb much more.

Obviously, this is a lack of consensus on this basic premise on which the emissions and current correction policy is based. The poor science is that nobody appears to have repeated the experiments of Tyndall to check the basics on which our emissions-reductions are based.

It's also poor science not to evaluate the success or failure of a procedure after 23 years of implementation.

I'll leave it there for now. But maybe you can understand Serpent why I'm querying two different reports on the status of polar bears. One implies that species can adapt to a one degree change of global temperature, and the other implies that such a change can cause species extinction.

We need less emotion and better science.

I had a look at your third reference which was a popular science account of a paper in Science Advances by Daniel H Rothman, titled Threshholds of Catastrophe in the Earth System in 2017 on this site -- https://advances.sciencemag.org/content ... 00906.full. He claims in the Abstract "Here, I hypothesize that perturbations of Earth’s carbon cycle lead to mass extinction if they exceed either a critical rate at long time scales or a critical size at short time scales." It was an hypothesis.

I must admit that the article was mainly beyond my comprehension, so I can't comment on it specifically. But it does occur to me that carbon exists in many forms, and that the land and atmosphere would also be flooded with carbon compounds if the ocean reached a critical concentration. The author does not mention the particular substances associated with the ocean content.

[doogles]

I am puzzled by the general idea that the consequences of global warming are something not to be emotional about. Alarm would seem to be a natural and survival-promoting response to events that threaten suffering and death. We humans have many emotions for powerfully adaptive reasons. Alarm says "do something!"

If anything, the media seem to be downplaying the looming prospect of a tipping point, where loss of ice and permafrost actually accelerates the feedback loop. I don't think many in the general public are aware of the methane hydrates loop or the permafrost-to-bog CO2 loop or other feedback mechanisms.
And many MSM owners are also invested in fossil fuels and/or cement production and/or Arctic mining ventures, etc. so it's not a real surprise that they don't want their audiences to be too "emotional" about what's happening right now. Getting emotional might lead to public demand for initiatives on both GHG reduction and on introduction of hygroscopic nuclei into the strat.

I take your point TheVat on the value of emotion and alarm. But it's not realistic to call for more action, unless you're sure that the action is going to result in something productive. Those people who become emotionally reactive can only achieve positive results if the emotional expression is directed towards a constructive goal.

Hence the need for more objective (non-emotional) thinking about how to control the gradually increasing temperatures.

I was pleased to read your final sentence -- "Getting emotional might lead to public demand for initiatives on both GHG reduction and on introduction of hygroscopic nuclei into the strat." At least the chanting protestors would have something to chant about if they incorporated more attention to cloud cover in their chants. I think you and I could easily produce such a chant if we took the time.

Which leads to the question of what the IPCC or anyone else has done about hygroscopic nuclei since 2013.

A good sign is that there appears to be more research going on with respect to cloud condensation and hygroscopic nuclei this year eg -- Yanwei Li (2019: https://link.springer.com/article/10.10 ... 018-1903-0) in a paper called Cloud Condensation Nuclei Activity and Hygroscopicity of Fresh and Aged Biomass Burning Particles, conducted laboratory accuracy experiments on a large variety of plants. YanMa et al (2019; https://www.sciencedirect.com/science/a ... 4217336380) performed a similar laboratory study of the burning of crop residues. This would of course create a problem with the philosophy of reducing carbon dioxide production, and someone would have to work out a balance. There's a bit of a dilemma in that reduction of carbon dioxide emissions also reduces the infusion of cloud condensation and hygroscopic nuclei into the atmosphere.

The first practical thought that comes to my mind is that controlled burning of forests in areas not likely to contaminate cities, should be encouraged all over the planet. The Australian Aborigines did this for 40,000 years. In fact, the practice seemed to be necessary for the germination of many Australian plant species. Any positive input from anyone? I'll continue searching.

This one -- by Robert Lange et al (2019; https://agupubs.onlinelibrary.wiley.com ... 19GL084142) conducted a K‐means cluster analysis of a five year aerosol particle size distribution (PSD) dataset from north‐east Greenland combined with measurements of coincident shorter field studies of aerosol equivalent black carbon (eBC) content, hygroscopic growth factor (HGF) and cloud condensation nuclei (CCN) concentrations. "This led to five clusters strongly controlled by natural emissions (eBC 8‐15 ng m‐3), and three anthropogenic clusters with larger particle concentrations in the accumulation mode (eBC 29‐77 ng m‐3). The HGF and CCN properties of the eight aerosol clusters differ drastically. Anthropogenic clusters feature high growth factors (1.62‐1.81) and low CCN κ‐values (0.10‐0.46), while natural clusters show lower HGF (1.38‐1.70) but remarkably higher κ‐values (0.35‐0.51). Extrapolating the CCN properties on the basis of the cluster analysis to annual timescales suggests that biogenic organic aerosol may drive Arctic aerosol production during summer." This one suggests that natural aerosols are better than man-made ones but it doesn't rule out our ability to produce greater quantities, even though they may be of lesser quality.

Yu Wang and Ying Chen (2019; https://agupubs.onlinelibrary.wiley.com ... 19GL082339) produced this Plain Language Summary of their research -- "Hygroscopic water uptake of aerosols can enhance its light extinction and cloud activation. Therefore, hygroscopicity of aerosol (κchem) is a key factor affecting its direct and indirect climate effects; however, long‐term observation of κchem in Delhi is absent. Here we demonstrate an approach to retrieve κchem from publicly available data sets of PM2.5 and meteorology and report the first long‐term estimation of κchem in Delhi is 0.42 ± 0.07 during 2016–2018. This value indicates only a supersaturation of ~0.18% ± 0.015% is required to activate a particle with 0.1‐μm diameter in Delhi, in contrast to ~0.3% supersaturation is required for Beijing and Asian average. It implies a higher water uptake and cloud activation ability for Delhi aerosols. Therefore, using Asian/Beijing averaged κchem to represent Delhi aerosols would lead to a significant underestimation of aerosol climate effects."

I can see where the last couple of references are helping to find solutions and knowledge about aerosols as cloud condensation and hygroscopic nuclei, but they don't provide any useful practical advice that I see can help to solving our need to generate more cloud. They do however, indicate that the Chinese and the Indians may be doing more research in this area than western scientists. What do you any of you think, as members of the SPCF? I'd like to hear the thoughts from more of you.

[Serpent]

There is a very simple solution.
Shut down capitalism.
Ain't gonna happen.
Do science, play with models, critique other people's conclusions to your heart's content.... or protest, demonstrate and rail against the machine.... or adopt the dog's philosophy, as the world's economic elites are doing. It makes no difference.

[TheVat]

So there is 'bleaching' of coral due to temperature changes of half to one degree C. How can this be so when the Great Barrier Reef covers 2000 km from north to south with a water temperature range of 10 degrees C, and when from winter to summer, the range in any given location is also 10 degrees C? Obviously, any species of coral in our Great Barrier Reef can withstand a 10 degree range. Am I missing something?

Yes. Along a north/south gradient the coral enter into a symbiotic relationship with specific species of algae, which are adapted to a particular temperature range and summer maxima for that latitude. Changes in average temperature year-round can be quite small and yet this average results from pretty intense rises in maxima in surface waters which different algal symbionts are differently adapted to. It takes a long time for a bleached coral ecosystem to shift adaptation to a different algal partner. That's why you have dead reefs that have become relative biological deserts.

https://www.nature.com/articles/s41586-018-0041-2 (abstract - the article has a paywall)

Also....

https://sciworthy.com/coral-is-sensitiv ... mperature/

Also...

https://skepticalscience.com/coral-bleaching.htm

Coral reefs operate very close to their maximum heat tolerance.


(been busy, so took me a few days to get back to this portion of your post. hope this helps)

[Serpent]

Retraction:
I was wrong about Greta Thunberg. She does know how to project emotion.
OTH I forgot to object to

Some use the emotional term 'global warming'.

The globe is warming. That's a simple statement. The relevant emotional term:
FIRE! FIRE! RUN FOR YOUR LIFE!!

[doogles]

So there is 'bleaching' of coral due to temperature changes of half to one degree C. How can this be so when the Great Barrier Reef covers 2000 km from north to south with a water temperature range of 10 degrees C, and when from winter to summer, the range in any given location is also 10 degrees C? Obviously, any species of coral in our Great Barrier Reef can withstand a 10 degree range. Am I missing something?

Yes. Along a north/south gradient the coral enter into a symbiotic relationship with specific species of algae, which are adapted to a particular temperature range and summer maxima for that latitude. Changes in average temperature year-round can be quite small and yet this average results from pretty intense rises in maxima in surface waters which different algal symbionts are differently adapted to. It takes a long time for a bleached coral ecosystem to shift adaptation to a different algal partner. That's why you have dead reefs that have become relative biological deserts.

https://www.nature.com/articles/s41586-018-0041-2 (abstract - the article has a paywall)

Also....

https://sciworthy.com/coral-is-sensitiv ... mperature/

Also...

https://skepticalscience.com/coral-bleaching.htm

Coral reefs operate very close to their maximum heat tolerance.


(been busy, so took me a few days to get back to this portion of your post. hope this helps)

Many thanks TheVat for those references about the coral reefs. They were all very helpful and constructive. The association between algae and coral were all new to me and not mentioned in my Biology schooling over 70 years ago.

I found the third reference very helpful because it had a blog at the end in which a number of people associated with coral biology took part. As in our forum, there were numbers who agreed or disagreed with certain aspects of the science. Apparently there have been many widespread bouts of coral bleaching in the past with a mixed range of outcomes from permanent damage to complete recovery. It is not new, but the general tone is that the current degree of bleaching is probably the worst.

The main authority seemed to be a Rob Painting who said in 2016 "Because reef-coral have adapted tolerance to a narrow band of environmental conditions, bleaching can occur for a number of reasons, such as ocean acidification, pollution, excess nutrients from run-off, high UV radiation levels, exposure at extremely low tides and cooling or warming of the waters in which the coral reside. Typically these events are very localized in scale and if bleaching is mild, the coral can survive long enough to re-acquire new algal partners. So bleaching in itself is not something new, but mass coral bleaching on the huge scale being observed certainly appears to be, and represents a whole new level of coral reef decline."

And the comment was made that bleaching was not so much due to single heat increase events, as to prolonged periods of heat exposure. It reminds me of sunburn.

It seemed highly probable that the 2015/16 damage was associated with prolonged periods of sea warming. It is not clear whether this warming was from an el nino effect or from prolonged solar radiation exposure or a combination of the two. If prolonged solar radiation exposure was a factor, then maybe radiation in the ultraviolet region of the spectrum could be involved? This would explain to me why warm water per se as a cause does not seem feasible in the Great Barrier Reef with its annual 10 degrees C range in temperature. I have swum in the sea in areas from Brisbane to Cairns and can verify that temperature changes personally. I like a hypothesis about anything to cover all aspects of the subject. It's a personal thing.

Regardless of that, if solar radiation is behind the warming of sea water and the bleaching of coral, then we need more cloud cover. Does this make sense to anyone? What better way to address average global near-surface temperature increases than to create more clouds. In the case of the coral reefs, it would be like putting a giant umbrella over them.

[TheVat]

Ghost Forests in the U.S.

Up and down the mid-Atlantic coast, sea levels are rising rapidly, creating stands of dead trees — often bleached, sometimes blackened — known as ghost forests.

The water is gaining as much as 5 millimeters per year in some places, well above the global average of 3.1 millimeters, driven by profound environmental shifts that include climate change.

Increasingly powerful storms, a consequence of a warming world, push seawater inland. More intense dry spells reduce freshwater flowing outward. Adding to the peril, in some places the land is naturally sinking.

All of this allows seawater to claim new territory, killing trees from the roots up.

Rising seas often conjure the threat to faraway, low-lying nations or island-states. But to understand the immediate consequences of some of the most rapid sea-level rise anywhere in the world, stand among the scraggly, dying pines of Dorchester County along the Maryland coast...

https://www.nytimes.com/interactive/201 ... rests.html

[doogles]

What a shame this article hasn't got some scientific quantitative data associated with it, TheVat! And what a shame that it doesn't make comparisons with other coastlines at a global level. Once again, my opinion is that this article is 'poor science' and also alarmist.

I note this early statement "The water is gaining as much as 5 millimeters per year in some places, well above the global average of 3.1 millimeters, driven by profound environmental shifts that include climate change." I notice that 'Climate Change' gets a mention as having a supportive role by the authors.

What happened to our consensus that global sea levels have risen 200 mm????? One may have to assume that the land mass may be sinking in these seawater-affected areas. You may remember an article I mentioned earlier that in the only longitudinal study of its kind to date, a study of aerial and satellite pictures to 2010 (from memory) of a group of 27 Pacific Islands has shown that only 14% have decreased in surface area, while most have remained the same or have actually increased in surface area -- in spite of a 200 mm rise in sea level.

I give credit to the authors for stating "The effects of climate change are also exacerbated by land that is sinking as a result of geological processes triggered by the end of the last ice age." I note that Climate Change comes first in that statement.

I can't see where 'Climate Change' needs to get a mention at all in this article.

I'm waiting for the time when it gets the blame for ingrown toenails.

I also note that these changes have been measured since 1938 which is long before the 'climate change' from 1970 -- "The Blackwater National Wildlife Refuge, where Dr. Gedan does research, lost 3,000 acres of forest and agricultural land between 1938 and 2006. More than 5,000 acres of marsh became open water."

Statements such as these do not help to get a balanced overview of the situation -- "Increasingly powerful storms, a consequence of a warming world, push seawater inland." Where is the evidence that storms are increasing and becoming more powerful?

This research by Wikipedia -- https://en.wikipedia.org/wiki/List_of_U ... hurricanes -- probably provides a better balanced perspective. Here are some excerpts -- "A total of 298 Atlantic tropical cyclones have produced hurricane-force winds in every state along the Atlantic Ocean and Gulf of Mexico (as well as Pennsylvania), with Florida having had more hurricanes affecting it than any other state.[1]"; "The 1990s were the most active decade for the United States, with a total of 31 hurricanes affecting the nation. By contrast, the least active decade was the 1860s and 1970s,"; "The 1935 Labor Day hurricane was the most intense hurricane to make landfall on the country, having struck the Florida Keys with a pressure of 892 mbar. It was one of only seven hurricanes to move ashore as a Category 5 hurricane on the Saffir-Simpson Hurricane Scale; the others were "Okeechobee" in 1928, Karen in 1962, Camille in 1969, Andrew in 1992, Michael in 2018, and Yutu in 2018, which had a landfalling pressure of 931 mbar, 932 mbar, 900 mbar, 922 mbar, 919 mbar, and 900 mbar, respectively."; "The 1900 Galveston hurricane was the deadliest hurricane in the history of the United States, killing between 6,000 and 12,000 people. 2017s Hurricane Maria resulted in at least 2,982 fatalities. The 1928 Okeechobee hurricane caused at least 2,500 fatalities, and in 2005, Hurricane Katrina killed approximately 1,800 people. In the 1893 season, two hurricanes each caused over 1,000 deaths.[3]" And those hurricanes before the 1950s had far smaller populations to affect.

So where are these 'increasingly powerful storms', and how were they 'a consequence of this warming world' back in the days before 'global warming'? As you can see from the records on the subject of 'powerful storms' alone, this article in the New York Times is quite unreliable.

Now I could produce a couple of newspaper articles written in 1922 on how the Arctic had disappeared, and another one from 1934 announcing how world catastrophes were increasing at an alarming rate, but they would be as helpful as this particular article about some localised coastal areas undergoing salination.

The way I see it, we need to urge the IPCC to get stuck into ways of producing more cloud, and ways of at least stabilising our population growth.

[TheVat]

Scientists have identified a surprising new mechanism that could be affecting cloud formation and weather patterns in the Arctic: bacteria from the ocean floor.

When tiny, plantlike ocean microbes known as phytoplankton die, their bodies sink to the bottom of the sea, becoming food for bacteria residing there. New observations made in the Bering and Chukchi seas off the coast of Alaska suggest that under the right conditions, these algae eaters are sloshed to the surface and from there are wafted into the air.

Once airborne, seafloor bacteria may become seeds that promote the growth of ice crystals, an important step in the formation of Arctic clouds.

“Clouds are super important in the Arctic,” said Jessie Creamean, an atmospheric scientist at Colorado State University and lead author of new research published in mid-July in Geophysical Research Letters.

https://www.washingtonpost.com/weather/ ... c-weather/

Another piece of the cloud formation puzzle. Much to be learned here.

[doogles]

That's sort of good news, TheVat, in that it's another acknowledgement that clouds could have an important role in increasing near-surface temperatures. Unfortunately the Washington Post now demands subscription to the magazine in order to view articles, so I am restricted to your excerpt for information.

I must admit that I'm fascinated by the mental image of bacteria on the ocean floor gorging themselves on phyto-planckton and then bursting upwards from the ocean floor up into the atmosphere where they act as nuclei for ice particle formation.

I've just had another look at the IPCC response to "What if the temperature rose by 1.5 degrees C?", which was published in 2018 after a request was received in 2016. It addresses carbon dioxide reduction as the only possible avenue of approach to controlling global mean surface temperatures.

A search for a mention of the word 'cloud' in the report produced no result. And this was in spite of the fact that their 2013 report acknowledged that cloud reduction resulted in more radiative forcing than carbon dioxide at the surface (4 W/m2 vs 1.6 W/m2). I don't understand why in 2013 the IPCC was talking about research into seeding the stratosphere with sulphurated compounds, and then failed to mention clouds in the above report. They did provide a sort of rider in their 2018 statement -- "C.1.4 Solar radiation modification (SRM) measures are not included in any of the available assessed pathways. Although some SRM measures may be theoretically effective in reducing an overshoot, they face large uncertainties and knowledge gaps, as well as substantial risks and institutional and social constraints to deployment related to governance, ethics, and impacts on sustainable development. They also do not mitigate ocean acidification. (medium confidence) {4.3.8, Cross-Chapter Box 10 in Chapter 4}" Obviously any attempts to indulge in solar radiation modification would involve cloud management.

And another obvious lack to my mind is that although they acknowledge that much of the cause of current Global Mean Surface Temperature (GMST) is anthropogenic, they have not suggested a single idea about controlling the rate of global population growth. There were 24 references to population as the word is used in sentences associated with effects on population. Their use of the acronym GMST by the way, in itself is also unscientific in my opinion. Those temperatures are taken four feet from the ground and in the shade of 'Stephenson Screens'. I've tended to use the acronym AGNST (Average Global Near Surface Temperatures) in my posts to date. To my mind, it's confusing for the IPCC to talk about temperatures four feet above the surface in the shade of Stephenson Screens when they also talk about Watts per square metre solar radiation, recorded at the surface.

It's just a personal thing.

[doogles]

While I'm on the job, I'd like to present another item of good news, something that's always lacking in IPCC reports.

Albert et al (2017; https://iopscience.iop.org/article/10.1 ... a7e68/meta) published an article titled Winners and losers as mangrove, coral and seagrass ecosystems respond to sea-level rise in Solomon Islands

Their Abstract states "A 2007 earthquake in the western Solomon Islands resulted in a localised subsidence event in which sea level (relative to the previous coastal settings) rose approximately 30–70 cm, providing insight into impacts of future rapid changes to sea level on coastal ecosystems. Here, we show that increasing sea level by 30–70 cm can have contrasting impacts on mangrove, seagrass and coral reef ecosystems. Coral reef habitats were the clear winners with a steady lateral growth from 2006–2014, yielding a 157% increase in areal coverage over seven years. Mangrove ecosystems, on the other hand, suffered the largest impact through a rapid dieback of 35% (130 ha) of mangrove forest in the study area after subsidence. These forests, however, had partially recovered seven years after the earthquake albeit with a different community structure. The shallow seagrass ecosystems demonstrated the most dynamic response to relative shifts in sea level with both losses and gains in areal extent at small scales of 10–100 m. The results of this study emphasize the importance of considering the impacts of sea-level rise within a complex landscape in which winners and losers may vary over time and space."

In spite of the differences in degree of recovery of corals, mangroves and seagrass, this does suggest that many species can adapt to rising sea levels and to whatever the change of temperatures may have been during that seven or eight year period.

We need more studies of this nature on the ability of species and ecosystems to adapt to change.

I say "Bring on the good news instead of 'Climate Change' pessimism.", and start/keep looking at alternatives to carbon emission reduction. Bring some human imagination into the problem.

[Graeme M]

Personally I am a bit nonplussed by the catastrophist argument. The near-surface atmosphere seems to have warmed by 0.8-1.0C since pre-industrial times and we don't observe truly worrying effects (although I know that scientists now claim there is the beginning of trends in some climate related events). Sea level rise appears stubbornly resistant to acceleration notwithstanding recent attempts to find that which have... succeeded, I suppose. Arctic sea ice has yet to fade away. On current trends, we can expect a rise of another, what, .12C each decade going forward? So it seems unlikely anything really drastic would happen any time soon. But who knows I suppose. Doogles, have you seen this? Reinterpreting Tyndall's experiments. I haven't watched nor read this stuff yet but the guiy has recently published it seems.


https://www.youtube.com/watch?v=T0IHKKkOwdU&t=860s

and

https://www.youtube.com/playlist?list=P ... W3P57C-eTb

[TheVat]

Not sure there is a general catastrophist argument so much as an awareness in the climatology fields and atmospheric physics that positive feedback mechanisms can kick in and our problems would somewhat accelerate. For example, while fluffy white clouds are cooling, water vapor is a powerful GHG and can accelerate warming cycles over seas and wetlands, so it's important to monitor vapor saturation where it's getting even a little bit warmer. And, in Canada and Alaska, there has been massive sea ice melting, and permafrost melts, both which can liberate methane hydrates and outgassing 25 times more potent than CO2. And, of course, where ice rapidly melts there is another positive feedback effect with lowered albedo and immense thermal storage from open sea.

We may want to look at measures, as others have noted in various threads here, such as pumping sea water into the air to form those lovely high albedo fluffy clouds that help mitigate rapid warming.

[doogles]

Graeme M, I watched the video and had some trouble comprehending the message. My rough interpretation was that a method of Spectroscopy called 'Raman' demonstrated some vibrational efffects on N2 and O2 in the infrared range. I think the author is suggesting then that these two gases could be absorbing IR in the manner of greenhouse gases 'a la Tyndall', and if this is so, then it would change the whole current understanding of the Climate Change science.

I can't comment personally, because I don't understand the method, but I note that following the video, one blogger (Richard Rothwell) stated "The absorption of IR radiation via the Raman effect is much, much, much weaker than absorption of IR radiation via the normal method. This means IR absorption by gases that absorb only by the Raman effect can be ignored for the purposes of the greenhouse effect."

What I found intriguing about the reference is that the bloggers were referring back to Tyndall's 1859 crude work with a tin of hot water and a galvanometer as the authoritative work on GHGs. The only quantitative information Tyndall presented was a visual observation of the degree of deflection of the needle on the old galvanometer. He was measuring absorption of 'heat' rather than infrared radiation. As I've said before, we're investing much into carbon dioxide-emission reduction, and yet, no one appears to have repeated and expanded on Tyndall's basic science with modern equipment.

Of interest, Tyndall did record a 'fraction of a degree' of deflection of the galvanometer needle for oxygen, nitrogen and hydrogen (see screen dump below).

Mmm. If that fraction was only a tenth of a degree, it may mean that N, O and H may have some greenhouse effect. N and O represent about 99.00% of our atmosphere, compared with 0.04% for carbon dioxide. That's about 2400 times as much. If Tyndall's absorption deflection for N and O was one tenth of a degree and that of carbonic acid (I assume it was nebulised) was 25%, then that's 250 times.

I'll stop my crude maths at that point, but Blair McDonald may have a point. Does this suggest to anyone else that we desperately need updated studies on the absorption and radiation properties on not only carbon dioxide now, but nitrogen and oxygen as well? This may just explain why Idso calculated that a doubling of carbon dioxide from 300 to 600 ppm cannot increase the near-surface average global temperature by more than 0.4 degrees C.

[Graeme M]

Doogles, I have no particular background in the science of GHGs, so can't really comment. It seems hard to believe there has been no experimental confirmation of Tyndall's findings though, are you sure this is the case? This said, I agree that IF N and O have some very slight absorption and radiation via the Raman effect (whatever that is), the fact that N and O predominate could mean sufficient amplification to produce a meaningful effect. On this tack, note the paper by Etminen et al, "Radiative forcing of carbon dioxide, methane, and nitrous oxide: A significant revision of the methane radiative forcing", which suggests a hitherto greater radiative forcing from shortwave absorption by methane. https://agupubs.onlinelibrary.wiley.com ... 6GRLEDHIGH

[Graeme M]

Vat, I don't know about in the US but here in Australia we seem to have rampant climate catastrophe alarmism. Extinction Rebellion is telling people they need to get the government to transition to fully renewable energy and electric vehicles by 2025 to save us from extinction. Numerous media articles sound like Doomer scripts with claims of the breakdown of civilisation within 10 years and so on. Schoolkids are even fearing for their lives. While there seem clear signs of some degree of warming from the temperature dataset and concomitant climate related events, I'm not sure they are THAT perilous as yet. Sure, tipping points *might* be reached but I don't think there is much evidence for that any time soon. All such suggestions are always couched in the language of might, may, could, which of course has always been the case. Things MIGHT happen.

[TheVat]

Yes, the alarmism doesn't help with getting the science done (nor does total denial). The stakes are high enough that a calm clear-headed approach is vital.


Tyndall experiment has been done many times, and is often done in physics classes....

https://aapt.scitation.org/doi/10.1119/1.2768699

https://aapt.scitation.org/doi/abs/10.1119/1.1987255

I think where research is lacking (or hard to find with casual search terms) is in getting a better dataset from professional labs on how much warming occurs from each GHG, with precise measures of kinetic energy changes in a countable set of molecules and countable monochromatic photons. It is reallly hard to find lab work that really gets into the basics of, say, longwave absorption by CO2 molecules, average kinetic energy changes, and so on. It's there, but I am going to have to take a few hours this weekend to refine search terms and wade through abstracts. I also want to look at research that looks at GHGs "in situ" i.e. in the atmosphere, where their distribution through the atmospheric column isn't the same as what is found in a lab setup.

[TheVat]

Here's a pretty good start, which may also interest Doogles, from Earth Science Stack Exchange....

https://earthscience.stackexchange.com/questions/7502/is-there-any-experiment-to-prove-that-co2-with-the-atmosphere-concentration-can

(relevant passage quoted below)

You seem to be particularly interested in laboratory experiments on carbon dioxide absorption. As an excellent starting point, I can recommend the (currently) 26 publications in AGW Observer's list of papers on laboratory measurements of CO2 absorption properties.

https://agwobserver.wordpress.com/2009/09/25/papers-on-laboratory-measurements-of-co2-absorption-properties/

If you're really keen to see experimental confirmation that CO2 can still absorb radiation even at atmospheric concentrations, you could take a look at (for example) Taylor and Yates (1957), Yates and Taylor (1960), or Streete (1968), all of which clearly demonstrate that CO2 absorption bands are present in normal atmospheric air.

As an aside: personally I find find that the numerous spectroscopic observations of the whole atmospheric column -- from satellites or ground stations -- provide a more compelling demonstration of the greenhouse effect. After all, the atmosphere isn't a homogeneous bottle of gas that can be faithfully scaled down into a lab sample. But your question and subsequent comments indicate that you're not interested in measurements of the atmospheric column itself, so here I'm just concentrating on ground-level experiments which demonstrate the long-wave absorption properties of CO2.

I hope that this may ease concerns that take the form of "no one has researched CO2 absorption since Tyndall 150 years ago."

[doogles]

Thank you for the response Graeme M. I'm so pleased that you were able to see that if N and O had a miniscule greenhouse effect, that they could they could have a meaningful effect overall. I'm surprised that no one else commented on that. Your contribution on Raman Spectroscopy caused me to have another look at Tyndall's work. I looked at his 'fraction of a degree' in a new light.

Methane is consensually regarded as having a high coefficient of absorption, but a very low volume among the atmospheric gases, but now that you come to mention that, I'm not sure where the basic work on methane was performed. It's not listed amongst Tyndall's gases, so there must have been another basic experiment somewhere.

You also said that "It seems hard to believe there has been no experimental confirmation of Tyndall's findings though, are you sure this is the case?" You'll note that I mentioned in my last post that the bloggers after Braithwaite's video only referred to Tyndall's work. All I can say is that I've spent hours chook-scratching amongst the literature without finding anything remotely approaching the rough quantitative work of Tyndall's. I've invited members of this forum to help with this search several times, because I'd love to see some sort of confirmation. Some years ago, one member gave me a list of 25 references. I went through the lot, but they all referred to work concerning the ranges of wavelengths at which carbon dioxide could be detected.

As you can see, TheVat has now presented me with a mountain of refs. I'll work my way through them.

I've given you a thumbs-up for your most recent post, because I agree with every word of it

[doogles]

I've given TheVat a 'like' because of the work and effort he has put into finding possible references. I give an 'A' for effort. It's no mean job. But please bear wih me for some days while I work through them.

I must comment on his last sentence though -- "I hope that this may ease concerns that take the form of "no one has researched CO2 absorption since Tyndall 150 years ago." I don't know if that was anybody's else's claim, but it certainly was not mine.

My personal problem is the absence of further quantitative evaluation of the properties of absorption and radiation of infrared radiation by the greenhouse gases (now including N and O). As I said in my second last post " ... we're investing much into carbon dioxide-emission reduction, and yet, no one appears to have repeated and expanded on Tyndall's basic science with modern equipment."

Just to remove any doubts as to what I have in mind, this is a mud-map of the equipment I would set up if I had access to a lab and some resources myself. It simulates Tyndall's equipment to some extent, except that instead of a can of hot water, we would have an infrared lamp (or range of such), a vacuum chamber instead of carbon rods and flame devices, and a spectrometer instead of a galvanometer. Between 1975 and 1980, I spent much spare time (weekends and days off) using an atomic absorption spectrophotometer at a regional university to analyse trace elements (for which radiation lamps were commercially available) in bovine blood samples to see if there was any correlation between clinical diseases and concentrations of those elements in blood samples.

In light of the posts initiated by Graeme M, I would now include N and O as well as carbon dioxide, nitrous oxide and methane.

[doogles]

Maybe I should expand a little on where my thoughts are, because some posts suggest a misinterpretation of what I have in mind.

Firstly I have no problems at all with the principles of the greenhouse effect and I have no problems with the claims that average near-surface global temperatures (ANSGTs) have increased by approximately 1 degree C or more over the last hundred years and that a percentage of this is anthropogenic.

I have problems with the apparent assumption that infra-red radiation is absorbed by carbon dioxide at a linear correlation rate, ie that a doubling of the concentration will result in a doubling of infra-red absorption.

This is in spite of the fact that a climate scientist of the reputation of Sherwood Idso produced a paper based on 8 separate studies of real world data, suggesting that a doubling of carbon dioxide from 300 to 600 ppm would raise the ANSGTs by only 0.4 degrees C.

I would like to see some more basic experimentation on this.

We need to be more certain that a reduction of carbon emissions will result in a slowing of the ANSGTs. So far there is not a single blip on the Cape Grim or Mauna Loa annual carbon dioxide curves after the 23 years since the Kyoto Protocol. I'm disappointed that no group has made an attempt to evaluate the success of this approach.

The experiment I have in mind would clarify some aspects of the above apparent contradictions. We need more basic quantitative experimentation.

Bear in mind that I have seldom undertaken a novel project in my life without modifying my original intentions as I go because of unforeseen problems or of insights into better procedures. I've seldom completed a novel project in my life in which I not had to modify my procedure. So my suggestions from here could undergo radical modification.

First I would produce a basic vacuum in the glass tube. Realising that a pure vacuum is impossible, whatever the available machinery achieves will be regarded as zero gas.

Room temperature will be recorded, the spectrometer will be set on an IR wavelength that gives high readings of absorption with CO2 and a series of 10 readings will be taken to produce a coefficient of variation for the reliability of the method. The Spectrometer readings will be regarded as zero gas absorption.

Secondly I would try a variety of inert gases at atmospheric pressure to see if any can be regarded as having 'zero' absorption properties. Argon appears to be a good prospect.

If I found such a gas, I would begin doing readings with increasing concentrations of high grade CO2, ranging from maybe 200 ppm in the inert gas at one atmosphere pressure up to 1000 or so ppm in 50 ppm increments. Obviously I would take repetitive samples at each concentration. Then we would have our first graph of a correlation between absorption of IR (at one wavelength) and increasing concentrations of CO2. If the results turned out to be constant and repetitive, we would have no more debate between people like Idso and the IPCC position. The basic science would be in, and we would know once and for all whether we should worry about a doubling of CO2 or whether we would find that a doubling of CO2 is not really an issue and that we should put our energies into other multiple-pronged attacks. Does this seem rational to anyone else?

Next, or even first up, we could measure just laboratory air after the inert gas experiment and see the readings on the spectrometer (CO2 would be c400 ppm). Then try increments of 50 ppm CO2.

After that of course, experiments could be performed using a large variety of computations and variations of pure gases (including N and O now), a range of lower pressures and temperatures and a range IR wavelengths.

How hard would this be to organise? It's a repeat of Tyndall's work with more modern equipment. If I was back in my 40s and still had access to such a lab, I'm sure I would have had a go at this personally. My biggest problem would be getting a glass blower to manufacture the tube required and to insert the required number of ports.

I'm sure anyone reading this can see what I have in mind, and I'm also sure that if any research group has already performed such experiments that they would have been cited in the mountain of literature on CO2 absorption of IR somewhere. To date I have not found anything resembling an up-dated repetition of Tyndall's work.

I'm about to go through the pile of literature that TheVat has dug up for me.

I must apologise to you, TheVat, in that I missed the New Topic you posted on Alt views on greenhouse gases absorption of longwave EMF. I think my eye caught the post by Graeme M in the Climate Change thread first. But I note that you virtually repeated the same reference list in the Climate Change thread.

[doogles]

I looked at all of the following. In a few cases, the Title or the Abstract (I had to copy and paste the Titles into Google Scholar) was enough to judge the nature of the content.

RE https://aapt.scitation.org/doi/10.1119/1.2768699 -- I have no problems with the principles of the Greenhouse Effect
Re https://aapt.scitation.org/doi/abs/10.1119/1.1987255 -- I have no problems with the principles of the Greenhouse Effect

Re Stack Exchange -- Earth Science Beta -- I couldn't work out who the person was who answered questions on this site, but I noted that he said the following at one stage "So in order to have a lab experiment that could replicate the mechanism of the greenhouse effect, we would need a vacuum chamber large enough to contain a vessel containing a column of air high enough to have a measurable lapse rate. This is clearly impractical. We can perform experiments in the lab to investigate the absorption of IR by greenhouse gases, and indeed Tyndall did this over a century ago, but we can't experimentally verify the greenhouse effect in laboratory conditions, just as we cannot experimentally demonstrate gravitational lensing in the laboratory." This suggests that my design of an experiment may be a waste of time, but I assume that it would be possible to alter the atmospheric pressure in the glass tube to simulate higher altitudes. Not only that, but the whole science of the greenhouse effect was based on Tyndall's findings. At least it would be a repeat and expansion of Tyndall's actual work and no doubt, support or cast doubt on some current assumptions.

I looked at the following -- 26 publications in AGW Observer's list of papers on laboratory measurements of CO2 absorption properties. Tyndall's work is listed at the bottom if anyone is interested. I have a feeling that this is the list that Natural ChemE provided me with a number of years ago. I can't find a repeat of Tyndall's work amongst the refs.

1 Spectroscopic database of CO2 line parameters: 4300–7000 cm−1 – Toth et al. (2008) -- Deals with wavelengths
2 Line shape parameters measurement and computations for self-broadened carbon dioxide transitions in the 30012 ← 00001 and 30013 ← 00001 bands, line mixing, and speed dependence – Predoi-Cross et al. (2007) -- Deals with wavelengths
3 Spectroscopic challenges for high accuracy retrievals of atmospheric CO2 and the Orbiting Carbon Observatory (OCO) experiment – Miller et al. (2005) -- This deals with the measurement of CO2 in the atmosphere
4 Near infrared spectroscopy of carbon dioxide I. 16O12C16O line positions – Miller & Brown (2004) -- Deals with spectroscopic wavelengths
5 Spectra calculations in central and wing regions of CO2 IR bands between 10 and 20 μm. I: model and laboratory measurements – Niro et al. (2004) -- Deals with wavelengths
6 Collisional effects on spectral line-shapes – Boulet (2004) -- Deals with wavelengths
7 On far-wing Raman profiles by CO2 – Benech et al. (2002) -- Deals with Raman Spectrometry of CO2 and N
8 Collision-induced scattering in CO2 gas – Teboul et al. (1995) -- Deals with wavelengths
9 The HITRAN database: 1986 edition – Rothman et al. (1987) -- Deals with wavelengths
10 Rotational structure in the infrared spectra of carbon dioxide and nitrous oxide dimers – Miller & Watts (1984) -- Deals with wavelengths
11 Broadening of Infrared Absorption Lines at Reduced Temperatures: Carbon Dioxide – Tubbs & Williams (1972) -- Deals with wavelengths
12 Investigation of the Absorption of Infrared Radiation by Atmospheric Gases – Burch et al. (1970) -- Deals with wavelengths
13 Absorption of Infrared Radiant Energy by CO2 and H2O. IV. Shapes of Collision-Broadened CO2 Lines – Burch et al. (1969) -- Deals with wavelengths
14 High-Temperature Spectral Emissivities and Total Intensities of the 15-µ Band System of CO2 – Ludwig et al. (1966) -- Deals with wavelengths
15 Laboratory investigation of the absorption and emission of infrared radiation – Burch & Gryvnak (1966) -- Deals with wavelengths
16 Line shape in the wing beyond the band head of the 4·3 μ band of CO2 – Winters et al. (1964) -- Deals with wavelengths
17 Emissivity of Carbon Dioxide at 4.3 µ – Davies (1964) -- Talks about emissivity of IR by CO2 at 1500K
18 Absorption Line Broadening in the Infrared – Burch et al. (1962) -- Effects of a variety of gases on the absorption bands of GHGs
19 Total Absorptance of Carbon Dioxide in the Infrared – Burch et al. (1962) -- Deals with wavelengths
20 Rotation-Vibration Spectra of Diatomic and Simple Polyatomic Molecules with Long Absorbing Paths – Herzberg & Herzberg (1953) -- Deals with wavelengths
21 The Infrared Absorption Spectrum of Carbon Dioxide – Martin & Barker (1932) -- Deals with wavelengths
22 Carbon Dioxide Absorption in the Near Infra-Red – Barker (1922) -- Deals with wavelengths
23 Observations on the Absorption and Emission of Aqueous Vapor and Carbon Dioxide in the Infra-Red Spectrum – Rubens & Aschkinass (1898) -- Deals with wavelengths
24 On the absorption of dark heat-rays by gases and vapours – Lecher & Pernter (1881) Svante Arrhenius wrote in his famous 1897 paper: “Tyndall held the opinion that the water-vapour has the greatest influence, whilst other authors, for instance Lecher and Pernter, are inclined to think that the carbonic acid plays the more important part.”.
25 The Bakerian Lecture – On the Absorption and Radiation of Heat by Gases and Vapours, and on the Physical Connexion of Radiation, Absorption, and Conduction – Tyndall (1861) This of course is the famous paper by Tyndall. I think that because this list virtually starts with Tyndall's paper, that the author who compiled it would have included any similar study. This site by the way will give you access to this paper, the only one I've seen on quantitative absorption of heat by a range of gases -- https://www.jstor.org/stable/108724?seq ... b_contents

So to date I have not seen anything resembling a repeat of Tyndall's work, but I would still appreciate others keeping an eye open for me.

[TheVat]

Somewhere I posted a link from a physics teachers website, in which it looked like Tyndall's experiment was so routine and widely done that it was a lab assignment in high school and college classes. Here it is:

https://aapt.scitation.org/doi/10.1119/1.2768699

I completely agree that more lab work is needed on reproducing the effects of a doubling of CO2 and how that affects longwave absorption across the frequency range, and where a saturation effect occurs. I welcome anyone who can point us towards research in that area.

[TheVat]

I hope my posts don't seem curt or brusque. Things got a little busy here lately. Will try to get to some of the List of 26 as time permits.

[doogles]

Somewhere I posted a link from a physics teachers website, in which it looked like Tyndall's experiment was so routine and widely done that it was a lab assignment in high school and college classes. Here it is:

https://aapt.scitation.org/doi/10.1119/1.2768699

.

You had already listed that experiment TheVat. It was the very first one I commented upon in my last post. I have no problems with the principles of the Greenhouse Effect. It's Tyndall's crude experiments on the quantitative properties of absorption and radiation of IR by carbon dioxide that does not appear to have been repeated.

I thank you for encouraging others to keep an eye out for such a repeat experiment -- "I completely agree that more lab work is needed on reproducing the effects of a doubling of CO2 and how that affects longwave absorption across the frequency range, and where a saturation effect occurs. I welcome anyone who can point us towards research in that area."

[doogles]

I've just had an afterthought on this topic as to why it's important to either find some repetition of Tyndall's work on the quantitative absorption and radiation if IR by carbon dioxide or else to urge somebody to do an experiment along the lines I've been discussing.

If it turns out that Tyndall's is the only such experiment so far, a point to remember is that his experiment did not study carbon dioxide per se. It studied carbonic acid, which is carbon dioxide in water. I would have to guess that he had to nebulise it.

But if he did use such a solution, his results would include the absorption effects of H20 as well as CO2. So the question to ask is how much of today's quantitative models on the effects of carbon dioxide on average global near surface temperatures are based on pure carbon dioxide absorption of IR and how much on H20?

[doogles]

This soft reference provided by davidm in another thread (https://cosmosmagazine.com/geoscience/w ... s-shifting) prompted me to post a further study relating to polar bears.

The article was written by Karl Kruszelnicki and purports to indicate that the Earth's polarity is shifting as we speak, because of Climate Change.

I was disappointed that Karl did not mention any scientific references in the article because I would like to have been able to check on the coefficient of variation of a measurement that detected differences of the order of magnitude of 6 or so cm over the distance from the North Pole to Labrador. I hope that all readers realise that in establishing the accuracy of any test of any kind, it is customary to do at least 10 measurements using the same machines or systems on the same item under measurement as quickly as possible to get a coefficient of variation of the test itself. And my experience in biological areas is that very few measurements of anything reproduce a consistency with a Standard Deviation of less than 0.01 of the mean. If these geographical measurements were made by satellites, the satellite would have to have been extremely stable and maybe even stationary to achieve such accuracy.

Naturally I would be pleased if anyone could give me a lead to the evidence that Dr Karl used in his soft reference.

But the above was just a side comment on that article. My main concern was that the article begins with this sentence -- "We are only a little way into the 21st century, but signs of a warming planet are already evident around the globe: More frequent droughts in East Africa; stranded polar bears in the Arctic; bleached coral reefs in the tropics; and retreating glaciers in the high latitudes. Along the coasts, sea levels are rising."

It disturbs me that such statements flow so readily off the typewriter or computer of such a well-known scientist as Dr Karl -- "More frequent droughts in East Africa (are evidence of a warming planet)." I've never looked at droughts in Africa before, but this article states that the records prior to 1980 on East Africa are sparse and somewhat unreliable -- https://www.researchgate.net/publicatio ... resilience.

I found another article on droughts in Africa based on records of longer duration. I like to see balanced reports. This one, in Wikipedia -- https://en.wikipedia.org/wiki/Sahel_drought -- has data going back hundreds of years and covers a much wider area. It therefore presents a more balanced picture with respect to 'climate change' effects. I'll present an excerpt -- "The Sahel has long experienced a series of historic droughts, dating back to at least the 17th century. The Sahel region is a climate zone sandwiched between the Sudanian Savanna to the south and the Sahara desert to the north, across West and Central Africa. While the frequency of drought in the region is thought to have increased from the end of the 19th century, three long droughts have had dramatic environmental and societal effects upon the Sahel nations. Famine followed severe droughts in the 1910s, the 1940s, and the 1960s, 1970s and 1980s, although a partial recovery occurred from 1975-80. The most recent drought occurred in 2012.
While at least one particularly severe drought has been confirmed each century since the 17th century, the frequency and severity of recent Sahelian droughts stands out. Famine and dislocation on a massive scale—from 1968 to 1974 and again in the early and mid-1980s—was blamed on two spikes in the severity of the 1960-1980s drought period.[1] From the late 1960s to early 1980s famine killed 100,000 people, left 750,000 dependent on food aid, and affected most of the Sahel's 50 million people.[2] The economies, agriculture, livestock and human populations of much of Mauritania, Mali, Chad, Niger and Burkina Faso (known as Upper Volta during the time of the drought) were severely impacted. As disruptive as the droughts of the late 20th century were, evidence of past droughts recorded in Ghanaian lake sediments suggest that multi-decadal megadroughts were common in West Africa over the past 3,000 years and that several droughts lasted far longer and were far more severe.[3][4]
Since the 1980s, summer rainfall in the Sahel has been increasing; this has been associated with an increase in vegetation, forming what has been called a 'greening' of the Sahel. The observed increase in rainfall is accounted for by enhancements in the African easterly jet, which is known to induce wet anomalies. A 2011 study found that the positional shifts in the African easterly jet and African easterly waves accompanied the northward migration of the Sahel rainband.[5]"

That history of droughts in the Sahel suggests that droughts there are a periodically-occurring phenomenon and not due to 'climate change' which is generally dated as occurring since 1970s. On the contrary, the Sahel appears to be 'greening' at the moment. I note that Dr Karl attributes the droughts in East Africa to a 'warming planet'. Is it possible to sustain a SANE discussion if we also blame the increased rain in the Sahel on a 'warming planet'. AS confirmation, I found a more up-to-date 2019 article on rain in the Sahel here -- https://onlinelibrary.wiley.com/doi/ful ... /wcc.591-- by Michela Biasutti in an article titled Rainfall trends in the African Sahel: Characteristics, processes, and causes, if anyone is interested.

I don't understand why our scientists are so selective in their presentation of research to the public, nor why they seem so convinced about what they are saying. I like a scientist to always manifest an element of doubt, and to present evidence rather than dogmatic conclusions.

The main reason I raised the subject of 'Climate Change' again was because just this week I came across what I considered to be a balanced article on the status of the stranding of polar bears which Dr Karl also included as evidence of a 'warming planet'. I published some references in this thread earlier about polar bears and about the mixed reports regarding their survival and adaptability.

This article -- https://zslpublications.onlinelibrary.w ... /acv.12439 -- by Hamilton and Derocher (2018) , titled Assessment of global polar bear abundance and vulnerability, made the point that Polar bears Ursus maritimus have become an iconic species for climate change , yet information on abundance and status for significant parts of their range is unknown. They point out the difficulties involved in keeping track of polar bear numbers.

The article is open-access and the following paragraphs that I cite, seem to indicate that we do not yet have enough objective data on polar bear numbers to make any scientific evaluation of the effects of climate change on those numbers and that 'ball-park' figures (not accurate data yet) suggest that their numbers may be on the increase -- "Mid‐20th century estimates for the global polar bear population ranged widely, from 5000 to 19 000 animals (Scott et al., 1959; Harington, 1964; Uspensky, 1965; Uspensky & Shilnikov, 1969; Larsen, 1972), but lacked scientific rigor, sometimes relying on educated guesses, as standard methods for polar bear population estimation had not been established. More recently, the global population of polar bears was believed to be between 20 000 and 26 000 animals (IUCN/SSC Polar Bear Specialist Group, 2010; Wiig et al., 2015). The global estimate, however, was acknowledged for its lack of precision and accuracy, and was not used for population assessment. Because of widespread interest in polar bears, the global estimate was sometimes referenced to satisfy public curiosity. Nonetheless, these estimates were misapplied by some to create doubt on the effects of anthropogenic climate change on polar bears (Harvey et al., 2018). Noting the challenges and expense of obtaining subpopulation estimates, Vongraven et al. (2012) proposed exploring occupancy models or extrapolation, yet there has been no effort to assess global abundance using such approaches."

I noted that Dr Karl uses the term 'stranding of polar bears'. I would be surprised if polar bears have not been stranded commonly over the past millennia, considering their habitat and the nature of their lifestyle. Certainly there are isolated reports of polar bears getting closer to settled areas, looking for food, but isn't this common to many species when natural food becomes scarce periodically? One of the scientific findings of the above article on polar bears by Hamilton and Derocher, was that the only correlation between polar bear numbers and a variety of other variables was the 'availability of primary prey'.

I'll leave it at that for now, but enough to say that I find statements such as "We are only a little way into the 21st century, but signs of a warming planet are already evident around the globe: More frequent droughts in East Africa; stranded polar bears in the Arctic; bleached coral reefs in the tropics; and retreating glaciers in the high latitudes. Along the coasts, sea levels are rising.", as not befitting a serious scientist.

[Serpent]

Australia is burning.
Or so I've heard. I can't prove it.