I was taught in high school in the 70’s that clouds and the phases of water perform this function. Read about it in Scientific American as well sometime in the 80’s or 90’s. But we now have first proof!~ctm
August 15, 2017
New data provides the first proof that the Earth has a natural thermostat which enables the planet to recover from extremes of climate change – but the recovery timescales are significant. This work is presented today at the Goldschmidt conference in Paris, and has just been published in the peer-reviewed journal Geochemical Perspectives Letters.
The idea of a natural temperature thermostat was first proposed in 1981, but until now no-one has been able to provide data to show that the recovery from the hot and cold temperature fluctuations were associated with a specific mechanism.
Now a group of British scientists has shown that recovery from global cooling events is associated with changes in the rate of weathering of rocks, which is the main mechanism of removing CO2 from the atmosphere. In weathering, rocks are dissolved by rain and river water; the process removes CO2 from the atmosphere, which is then transported to the seas by rivers to be locked up in carbon-rich rocks such as limestone. The more weathering, the more CO2 is removed from the atmosphere.
The team had previously found evidence supporting the role of weathering in cooling the Earth in times of high temperature. This current work confirms that a slow-down of weathering takes place in cold periods, and so supports the concept of an “Earth thermostat”.
The researchers were able to use the Lithium isotope ratios in rocks as a measure of weathering. They examined rocks from the period of the Hirnantian glaciation – around 445 million years ago – which correspond with the second greatest extinction of life in history, when around 85% of marine species were wiped out, due to the cooling and a dramatic drop in sea levels (estimated at around 80m) as water was locked into ice fields and glaciers.
The samples, which came from Anticosti Island (Quebec, Canada), and Dob’s Linn (near Moffat, Scotland), show that global chemical weathering rate declined by a factor of four temporarily during the 5°C cooling that caused the glaciation, removing less CO2, allowing the climate to recover from the cooling.
Lead scientist, Dr Philip Pogge von Strandmann (University College London and Birkbeck, University of London) said:
“From looking at the relative abundance of lithium isotopes in ocean-derived rocks, we were able to confirm that chemical weathering is the driver of the Earth’s natural thermostat. When there is a warmer climate, there is more weathering, and when it is cooler there is less weathering: this is what you would expect, given that chemical reactions go faster with increasing temperature. So more weathering removes CO2 from the atmosphere and puts a break on global warming. However, when the temperature cools, the reverse is true, and less CO2 is removed from the atmosphere in cold periods. This is the process that has allowed life to survive on Earth for around 4 billion years, and is what we are reporting in Paris”.
Nevertheless, we need to be clear that the changes in temperature are gradual, and that recovery can take hundreds of thousands of years. Given the rapid increase in the rate of global warming at present, this kind of wait is not an option for us”.
HT/Doug
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Question: can anyone supply me with a web link that shows real time satellite photos of Antartica? Thanks in advance.
Climate scientists get all giddy when they see the word “weathering”. They suspend all rational thought when it is used an explanation for anything.
Weathering is only 0.02% of the annual carbon cycle and thus plays absolutely no role whatsoever in the CO2 levels in the atmosphere.
But let’s think of the cloud feedback mechanism in the theory.
You put more water vapor in the atmosphere and you get less clouds.
You put less water vapor in the atmosphere and you get more clouds.
It’s a no-brainer that this is just wrong.
Can someone explain to me HOW rock weathering can remove CO2 from the atmosphere?
In other words, rock weathering is a cause or an effect?
Correct me if I’m wrong, but basically CO2 from air reacts with water and Ca in rocks, creating calcium carbonate. Acid rain weathers rocks. Weathering is an effect of CO2, and sequestering is an effect of weathering.
The process is slow, because CO2 makes rainwater only mildly acidic, but eventually much of the free CO2 is bound to limestone. Tectonic movements may break the CaCO3 and free the carbon dioxide in some hundreds of millions of years, so there is a slow recycling going on all the time.
In my opinion, the theory is beautiful, but the problem is there’s a false dichotomy that CO2 is a primary climate driver. The Sun and oceans are much more important than CO2, be it at 300 or 400 ppm. And I’m still pretty sure we can’t get it to 600 ppm. Even if we tried particularly, but certainly not by accident. The oceans eat up too much CO2.
So let me see if I well understand. Water in the surface of rock react with CO2 just above it and CA of the rock and create calcium carbonate. Say a thin layer over the rock that will be removed by the acid rain?
Is it correct? If so, my question is: “How much CO2 is involved in such a process around the Earth?
I’m sick of warmest articles that confuse climate with weathering events!
So we need to paint the rocks? Or bust up rock depending which T we want? Ha!
I read about a guy who had a near death experience. He went to heaven for a while. They told him that mankind was going to learn how to control the weather. Ergo, I conclude this paper may be a gift from heaven.
If and only if CO2 is the primary driver of warming, which I don’t believe is valid Too bad they couldn’t “calculate” the concentration of carbon dioxide.
Hey that’s an interesting take. Take past temperature (say 10000 years), and based to variation in temperature, calculate the amount of CO2. Should be easy, if it is the primary driver.
Well, obviously not.
Sounds like a model-buster to me!
You must bear in mind that back in your school days, the science community was very primitive, They could only do things like split the atom, invent radar, go to the moon and other silly little things like that.
These days the scientific community can do wondrous things like develop climate models to the nth degree despite false assumptions and they can arbitrarily homogenise data like the world has never seen before.
The atmospheric temperature is driven mostly by its mass, volume and pressure, not by composition. Observable in Venus and Mars.
The moderator did not noticed that the idea about CO2 controlling the climate is the old claim by IPCC- minded scientists. The referred study claims that CO2 is also guilty for glaciations and this would mean that CO2 is responsible for all extreme climate periods on the Earth. No way.
There is a natural thermostat, however it has nothing to do with CO2. It’s the water cycle.
Water evaporates and cools the surface, it then moves up into the atmosphere where it condenses and releases that heat to space.
As the temperature warms, the water cycle speeds up and removes more heat. As it cools, the water cycle slows down.
More evaporation also means more clouds. One cloudiness-% has 0.1 Celcius degrees temperature effect.
Whether the weathering weather would show,
When fierce dry or humid winds do blow.
Carbon dioxide in rain, ice, and snow,
Corrodes rocks, with mildly acidic flow.
Geologists swoon over rocks from the moon
And CO2 corrodes our rocks too soon
But temperature trends from midnight to noon
Result from water, not gas, ya cloon!
You’re not the “cloon”, Tom. It’s the geologist/theorists/warmists.
🙂
A couple of troubles with this idea:
a) evidence of a much smaller temperature sensitivity to CO2 increases than had been proposed a decade ago are seeming more likely (warming from models 3x observations, and more if cooling resumes)
b) natural variation (the Pause for example and a series of major warm and cool periods throughout the Holocene with relatively little change in CO2 ) is gaining weight as the main cause of warming and cooling on all scales. A decade ago, natural variation was opined by the consensus to be insignificant, but since, the major ocean oscillations (pointed to by sceptics) have been ‘discovered’ by the consensus when the Pause and clear correlations with global temperature forced their consideration.
c) except for the tropics, the effect of weathering is truly skin deep and that ‘skin’ attenuates further weathering. For the tropics weathering is deep but temperature there doesn’t change much over major global warming and cooling cycles. A look at rocks scraped and polished across the Canadian Shield by the last ice max still retains a high polish and fine scratches are preserved. Weathering over the Holocene is not very significant. Can’t find a decent glacially polished Precambrian granite picture.
The gray body temperature in our orbit is about 279K . Nothing can get us very far away from that .
I think we can safely say that ‘proof’ ain’t what is used to be!
This study is absolutely no proof at all. Sure, reacton rates increase with temperature. That has been known for hundreds of years. Nothing new at all here. Still absolutely no proof that CO2 had anything to do with controlling temperature though.
My daughter bought a water carbonation bottle (old term ‘siphon’?) which uses a small CO2 capsule. The pressurized gas is introduced above the water level in the flask. I was amazed that dissolution of CO2 was almost instantaneous, orders of magnitude more soluble than salt or sugar. This assures me that where water vapour is present in some ordinary amount in the atmosphere, the 400ppmv CO2 must virtually all be dissolved in water. Where it rains, it most certainly is.
Does carbonic acid have a similar spectral absorption to CO2? I suspect not (I looked for data). If I’m correct, then water in the atmosphere has more effect than just its absorption of LWIR and the enthalpy differences of its phases. Does combination with H2O reduce CO2 LWIR?
I suspect I will hear from someone on WUWT on this.
All discussion of chemistry and volcanism aside, I’m totally puzzled as to what correlation between weathering and temperature they’re talking about. They describe a process that takes at least ‘hundreds of thousands of years,’ yet it’s clear from various proxy records that significant temperature changes have been much more rapid on multiple occasions.
Ten years ago a Dutch professor proposed to use olivine to bind CO2.
Not much heard about his project since then.
https://www.trouw.nl/groen/emeritus-hoogleraar-gelooft-nog-steeds-in-olivijn-een-steen-die-co2-slurpt~a04b2ade/
Here’s a link to that “Scientific American” article, written back when the magazine was not anti-science and not anti-American:
http://jvarekamp.web.wesleyan.edu/CO2/359%20CC%2008/Scientific_American_88.pdf
Statistical analysis of the time series for atmospheric CO2, (Mauna Loa, Macquarie Island, Mount Waliguan) and satellite lower troposphere temperature, UAH, show that the temperature drives the rate of change of CO2 concentration. As the Tropics has the highest average temperature it must produce CO2 at the greatest rate across the globe. That CO2 must disperse North and South away from the Equator into the Polar regions. As the solubility of CO2 increases with decreasing temperature it must be precipitated at the Poles within the ice and snow or as dry ice when the temperature is below the sublimation point of -78 degrees Celsius. That is, there is a continuous circulation of carbon from the Equatorial Zone through the atmosphere as CO2 to the Poles where it is locked into the Polar ice sheets until those sheets move sufficiently far from the Pole to melt and the CO2 becomes a component of sea water.
The Tropics is a source for the atmospheric CO2 and the Polar regions are the sink.
Rainwater containing dissolved CO2, which causes weathering of rocks to form calcrete, is yet another sink.
This seems to accept the premise that carbon dioxide is a significant driver of “global temperature”, whatever that is.
If we substitute “heat in the climate system” for “global temperature”, I’m still skeptical that carbon dioxide content has particularly much influence.
“global chemical weathering rate declined by a factor of four”
Whenever i see statements like this, it’s like nails on a chalkboard to me. Assuming the weathering rate cannot be negative (and I don’t even know what that would mean), it cannot possibly decrease by a factor of more than one. If you decrease anything by a factor of one, then it is, by definition, zero.
Let me show it mathematically, if R0 is the original rate of weathering, and R1 is the new rate, and F is the factor by which the rate decreases, then:
R1 = R0 – FxR0
if F = 1, then R1 = R0 – 1xR0 = R0 – R0 = 0.
If F is 4, then R1 = R0 – 4xR0 = -3R0. So not only did weathering completely cease, but some process of “REVERSE-weathering” took over, and was three times as strong as the previous weathering was. or in other words during the Hirnantian glaciation, material was ADDED TO the rocks, at 3 times the rate that it is eroded from the rocks during warmer periods. This is, of course, impossible (or at least impossible for it to have been caused by rainfall or lack thereof).
What the authors, I believe, are trying to say is that the weathering rate during the Hirnantian glaciation was ONE-FOURTH of what it was during warmer periods. The decrease, therefore, is only by a factor of three-fourths.
It’s similar to the sign on water-conserving urinals you sometimes see in men’s restrooms. They proudly proclaim to “use 8 times less water per flush than standard urinals”. What they really mean is these urinals use 1/8 the water of a standard urinal, but that’s not what the actual words mean. If a standard urinal uses 1 gallon per flush, then “8 times less” means 8 gallons less than the 1 gallon per flush of a standard urinal. 8 gallons less than 1 gallon is -7 gallons. So not only do these magic urinals not use any water at all, flushing them actually increases the water supply, by 7 gallons per flush. If this were true, we could resolve any drought anywhere by installing a few of these urinals and just hiring people to flush them constantly until the water levels are restored.
“The main mechanism for removing CO2 from the atmosphere” is NOT rock weathering, it’s photosynthesis. This is compensated by respiration and carbon dioxide exsolution from warming oceans, of course. Permanent removal of CO2 is effected by shell rain along with carbon pumping to the ocean depths, too, but the point is moot. CO2 is NOT a greenhouse gas, and it doesn’t cause global warming (it absorbs and re-emits by line spectra in the bandwidth 13 to 17 microns, which corresponds to temperatures of -51 to -103 degrees C, well below normal Earth surface temperatures, and therefore can’t possibly contribute to global warming.)
I find it highly irritating that such willful and especially peer-reviewed disregard of important principles of Earth science can so profoundly hamstring scientific research, thereby hindering the further understanding of the actual workings of the Earth system. Unfortunately, this revered arcane belief in the CO2/warming link pervades geological, oceanographic, and climatic investigations to a depressing degree and is found almost everywhere one looks. Nonetheless, one single hard-data confirmation of the principle in fact still remains to be found in the scientific literature. As I understand things, to be considered valid, all good scientific theories MUST be supported by multiple sources of hard evidence, but greenhouse warming theory has been somehow unaccountably excepted from this vital constraint. Isn’t it about time that something was done about that?