The Geological Record of Climate Change and Why Today’s Increase in Atmospheric CO2 Is the Result of Global Warming, Not the Cause

David Shelley*

The climate is changing, and the geological record of climate change clearly shows that (a) we live in an unusually cold climate, (b) recent warming is neither dangerous or unusual, and (c) the main drivers of climate change are the sun, the oceans, and plate tectonics.

First, I will describe climate change over the last million years, and especially the last 120,000 years, including local (Christchurch, NZ) and other well-known examples. Then I will put this in the context of the last 540,000,000 years, a period known as the Phanerozoic during which most complex life forms developed and evolved. This period was almost always much warmer than today, with this warmer climate being punctuated by three important cold periods, one of which we remain in today.

I will then discuss in section 3 below the roles CO₂ and our emissions play in climate. I will argue that almost all our emissions should have dissolved in the oceans to maintain an equilibrium partitioning of ca. 50/1 CO₂ between the oceans and the atmosphere, which means that all other things being equal, CO₂ levels in the atmosphere should have risen by only 7 ppm. This is not what has happened, and climate scientists have proposed, therefore, that our CO₂ emissions must “hang around” in the atmosphere for 300 to 1000 years. However, that idea makes no sense, given that every water droplet in clouds is dissolving CO₂ and transporting it via rain into the oceans. No reason to hang around at all. Instead, I propose that the observed ocean warming since 1905 (probably due to the sun, possibly volcanic activity) has resulted in the release of oceanic CO₂, which is the main reason why atmospheric CO₂ has increased by 140 ppm. I propose, too, that ocean warming is responsible for warming the lower atmosphere. Our emissions play no part whatsoever in the global warming.

I go on to discuss the disgraceful mismatch between facts and the political and activist commentaries on present-day warming. It is remarkable that the UN and climate activists do not correctly report what the Intergovernmental Panel on Climate Change (IPCC) concludes about severe weather events and their frequency. It is a fact that the IPCC finds no clear evidence for attributing most such events to the influence of human emissions.

I provide a section on agriculture and methane emissions. It is significant that a distinguished climate scientist has recently described those emissions as “not a problem”.

Finally, I discuss what comes next, climate-wise. A very cold glaciation in 80,000 years is probable. In the meantime we do need to cut our use of fossil fuels, but there is no rush, and we would do this, not to control emissions or climate, but because fossil fuels are valuable finite resources.

*David Shelley gained his PhD from Bristol University and then lectured in geology for nearly 40 years at the University of Canterbury, Christchurch, NZ. He was Dean of Postgraduate Studies for 6 years. He is the author of 62 research papers and two textbooks, one on mineralogy, the other on igneous and metamorphic petrology.

1. The last one million years of climate change

We live in a very cold period of Earth’s history, with the last 1,000,000 years or so marked by regular oscillations (roughly every 100,000 years) from extremely cold glacial periods to relatively short warmer periods of the order of 10,000 years long that are called interglacials. The following figure shows the well-known parallel ups and downs of temperature (T) and CO₂ recorded in ice cores from Antarctica over the last 450,000 years. Note that Ts in the interglacials 125,000 and 325,000 years ago were higher than those today. Note, too, that the present interglacial is marked by several rapid oscillations of T. It should also be noted that Ts in the tropics did not change markedly while Ts were oscillating wildly at the poles. I will show later how these Ts relate to global average Ts and latitude.

Time series of temperature and CO₂ concentration from the Vostok ice core, retrieved, respectively. From Koutsoyiannis D, 2024, https://www.aimspress.com/journal/MBE, and in turn from http://cdiac.ess-dive.lbl.gov/ftp/trends/temp/vostok/vostok. 1999.temp.data from http://cdiac.ess-dive.lbl.gov/ftp/trends/co2/vostok.icecore.co2

The maximum T of the present interglacial was reached about 8,000 years ago, and it is known by geologists as the Holocene climate optimum. This T maximum was marked by a sea level ca. 2 metres higher than today. Ts have generally cooled since then with several fluctuations, one of which we are experiencing today as a slight global warming. Locally, around Christchurch, the evidence for the higher Holocene climate optimum sea level is clear. Ditches in the Dallington region exposed deposits of flat beach pebbles, marking the higher coastline, and alongside the road between Tai Tapu and the Gebbies Pass turnoff there is a series of sea cliffs and wave cut platforms in the volcanic rocks of Banks Peninsula that mark the higher sea stand. The high sand dunes alongside Linwood Ave near the Avon River probably relate to this higher sea level. Evidence for similarly high sea levels and Ts has also been found in the Thames and Northland regions of NZ, along the east coast of Australia, and generally around the world. The famous stone village of Skara Brae in the Orkneys dates back some 6,000 years, and the local vegetation at that time indicates a warmer climate.

The fluctuations of T during the Holocene have been marked by retreats and advances of mountain glaciers. The historical evidence of glacial advances during the Little Ice Age over the last few hundred years in the European Alps is well known. Now, with modern warming, glaciers are retreating, but as they retreat they reveal the remains of older Holocene forests, which clearly show that the glaciers had retreated previously to a greater extent than today. How, otherwise, did Hannibal get his elephants over the Alps? The same situation is found in Scandinavia and Alaska. The present-day retreat of glaciers in NZ must be seen in this context. Nothing extraordinary is going on.

Twenty thousand years ago, at the height of the last intense glaciation, all of Canada and northern Europe (including much of Britain) was covered in ice sheets, many more than a kilometre thick. The South Island lakes of NZ did not exist, because those valleys were filled with ice up to ca. one kilometre thick. This huge amount of ice meant that sea levels globally were ca. 140 metres lower than today. In Sumner, Christchurch, you’d need binoculars to see the shoreline way away in the distance from the present-day beach. Imagine, no North Sea, no English Channel, no trees in Canada or Britain (Britain had ice sheets in the north and a cold frozen treeless land in the south). Coastlines globally were hugely different from today, with vast coastal areas exposed that have now been swamped by oceans that have risen by 140 metres. The ice would have been slow to melt in the first stages of interglacial warming, but the rapid rise of Ts into the Holocene climate maximum would eventually have been accompanied by huge amounts of melting and sea level rises of at least the order of 2 metres every 100 years. This substantial and rapid global warming from 20,000 to 8,000 years ago took place without the influence of any human-generated CO₂. The Holocene climate optimum was marked by the development of the Sahara desert, which previously had been a watery lush area occupied by humans. As climate change and the developing desert made life impossible, the tribes of the Sahara region moved to the Nile River where they engineered irrigation schemes watered by the Nile and established the great Egyptian civilization.

One hundred and twenty-five thousand years ago, at the height of the last interglacial, Ts were higher than those of the Holocene climate optimum, and sea levels were ca. 10 metres higher than today. Evidence is easy to find, and includes the Florida Keys, which represents a barrier coral reef that grew at that time but is now stranded because of the onset of the last glaciation that lowered sea levels by ca. 150 metres, followed by the present-day interglacial and oceanic rise of ca. 140 metres. London at this time had something approaching a Mediterranean climate, as recorded by fossils now on display in a London museum. I believe evidence for this high stand of 10 metres can be seen around Sumner in Christchurch, NZ (my observations, not closely examined and studied — a good project for a student?). The cliffs at Whitewash Head seem to display a large wave-cut platform that extends out to sea about 10 metres above present sea level, and I suggest that Cave Rock, Shag Rock, the old flat-topped sea stack on Nayland St to the west of the library, the flat topped cliff at the west end of Peacocks Gallop that once connected with the top of the higher pre-earthquake sea stack of Shag Rock, and the flat-topped sea stack at the western end of Beachville Rd in Redcliffs, are all remains of this ca. 10 metre-high wave-cut platform of 125,000 years ago.

To summarise, over the last million years, every 100,000 years has been marked by a glaciation with sea levels some 140 metres lower than today, and with huge kilometre-thick glaciers covering vast areas of north America and Europe (and filling all the glacial lakes of southern NZ). The Great Barrier Reef of Australia, which would have re-grown during each interglacial, would have been left stranded during each glaciation as a >100 metre-high exposed mass of dead coral that would have been massively eroded by the colder oceans during storms. During every interglacial, for a relatively short time, the barrier reef would have grown again as sea levels rose and ocean Ts rose, only to be left stranded and exposed above sea level every time a new glaciation was initiated. The reef is therefore very much a temporary feature that comes and goes with these regular fluctuations of T and climate. Coastlines changed dramatically with the repeated huge changes in sea level. Fauna and flora would have been under almost constant pressure to migrate and evolve dynamically as the environment was undergoing these dramatic changes.

The last 100 years of global warming is almost imperceptible and inconsequential in the context of all this. Now, let’s look at the broader geological picture of the Phanerozoic.

2. Climate change during the Phanerozoic — the last 540,000,000 years

Geologists have been gathering evidence about climate change for more than 200 years, long before anyone else had even thought about the subject. I was very lucky to study geology first in the 1950s as a schoolboy in South Wales, UK. Cycling from my home, I was able to examine a succession of rocks 425 to 200 million years old that started with coral reefs, then desert sands, coral reefs again, a rain forest (coals and river sands), more desert sands, and finally warm sea deposits. Three times South Wales had been under the sea, twice above sea level, and the changes in climate were obvious. South Wales is presently above sea level and a wet, green, temperate place, but I was aware that much of Britain had been covered very recently in thick ice, making South Wales uninhabitable until ca. 10,000 years ago. Climate change indeed. I am old enough that my early days of geology predate the development of the theory of plate tectonics, and understanding the geological record of climate change was then difficult. What a revolution plate tectonics was, opening our eyes to much more cogent explanations of what has been happening over many millions of years.

Geologists have long been aware that Earth has usually been much warmer than today. A recent synthesis of the data is that of Scotese et al., published in Earth Science Reviews in 2021, and figure 23 from that paper is given below. It shows just how very low the present-day global average T of 14 °C is (far right of the diagram). It shows three very cold periods at ca. 450 million years (Ordovician), 300 million years (Carboniferous–Permian), and the present day. It also shows how much warming would be required to escape from the present glaciation. Scotese et al. support the general idea that human emissions are causing global warming. I will argue against that later. The main point I would immediately make is that more global warming would simply restore Earth to a more normal climate. We should not be alarmed by it, because animals and plants thrived during the very warm periods of Earth’s history. Strangely, however, the greatest ever mass extinction event (perhaps 96% of species became extinct) took place 252 million years ago at the end of the Permian ice age when Earth was warming. We do not know the reason.

The record of average global temperatures over the last 540 million years, and the projection of future global warming onto the Phanerozoic Temperature Time Scale. The likely amount of Post-Anthropogenic Warming (PAW) (red line). The boxes indicate times in the geological past when global temperatures were within the range of predicted PAW. When the Global Average Temperature is below 18 °C large polar icecaps can form. When the Global Average Temperature is above 18 °C large polar icecaps are unlikely to form.

Figure 7 from the Scotese et al. paper is shown next, and it shows what global average Ts of between 8 and 23 °C would mean in terms of Ts from the poles to the equator. The coldest 8 °C global average T would mean Ts of minus 50 °C at the poles but with Ts remaining close to 30 °C at the equator. The present-day global average T of ca. 14 °C is shown as a dashed line. Ts at the equator will never vary much from 30 °C while Ts at the poles will vary markedly with any change in average T. For 63% of Phanerozoic history, the global average T has been between 19 and 21 °C, which is 6 °C on average warmer than today. The very slight global warming of the last 100 years is really neither here nor there, and the very idea that Earth is facing a threat to its very existence, or in the words of the UN, entering an era of global boiling, is simply stupid.

The polar temperature and the Pole to Equator temperature gradient for different Global Average Temperatures (GAT). Polar Temperature = average temperature above 67° latitude (N&S), Deep Sea = the average temperature at the bottom of the oceans (after Valdes et al., 2020). Pole to Equator Gradient = the average change in temperature for every one degree of latitude measured between 30° and 60° latitude. The Pole to Equator temperature gradient is shallow near the Equator and steepens rapidly near the Pole. The plus signs are the combined average temperatures for the present-day northern and southern hemispheres. Frequency = the percent of the time during the Phanerozoic characterized by this Pole-to-Equator temperature gradient. All of these calculations are based on an average tropical temperature of 26 °C (15 N – 15 S).

3. The drivers of climate change

The IPCC was set up to investigate the relationship between modern global warming and our CO₂ emissions. A reasonable hypothesis is that if CO₂ is a potent greenhouse gas, then our emissions may be causing global warming, perhaps dangerously. But if we are doing science, we must also consider the possibility that CO₂ is not a potent driver of warming, and that the warming we observe is the result of something else. Unfortunately, the IPCC has become completely obsessed with the idea that CO₂ is the potent driver of warming. It quickly rejects any other possibility. Yet a key factor in assessing the potency of CO₂ is knowing a value for the so-called climate sensitivity of CO₂. A sensitivity of 1 would mean that a doubling of CO₂ in the atmosphere would warm Earth by 1 °C (hardly a threat to Earth’s existence), a sensitivity of 6 would mean a warming of 6 °C. Yet even the IPCC admits we still do not know what the sensitivity is. The literature is filled with estimates that range from less than 1 to 6 (figure below). How then can one put any faith in the modelling of climate scientists when one of the most fundamental factors is unknown? Modelling may be a useful adjunct to science, but it is not real science. Science must be based on facts and observations, not predictions based on uncertainties. The fact that there have been innumerable attempts to model future Ts, all giving different answers, and with nearly all of them running hot relative to real observations, means the results of modelling are simply not credible. Yet these models are used by the UN to threaten us with doom and gloom. So let us look at alternatives to the IPCC narrative.

The hypothesis underlying the IPCC narrative can be summed up as follows. (1) CO₂ is a greenhouse gas (TRUE, but we must remember we really do not know how potent it is as a greenhouse gas). (2) We are emitting CO₂ into the atmosphere by burning fossil fuels (TRUE). (3) The amount of CO₂ in the atmosphere is increasing (TRUE). (4) Earth is warming (TRUE). (5) Therefore, our emissions are causing global warming (NO. This is the flaw in the argument, as I will explain here).

Our emissions are tiny in amount relative to the total amount of carbon in the ocean–atmosphere system. According to the IPCC (2022), our emissions since industrialization amount to 2500 GtCO₂, the equivalent of 320 ppm CO₂ in the atmosphere. The oceans contain 50 times more C than the atmosphere, and this ratio of 50/1 must represent some sort of dynamic equilibrium partitioning of the CO₂ between ocean and atmosphere. To maintain that equilibrium, one would have expected 98% of our emissions since industrialization to have been taken in by the oceans, leaving 50 GtCO₂ in the atmosphere (just 7 ppm). Clearly, this is not what has happened, because atmospheric CO₂ has risen since industrialization from 280 ppm to 420 ppm, a rise of 140 ppm, not just 7 ppm. NASA suggests, therefore, that CO₂ must hang around in the atmosphere, residing there for anything between 300 and 1000 years, causing global warming. However, we know that (a) CO₂ dissolves very easily in water, (2) the atmosphere is far from static, and often very turbulent in stormy weather, (3) the oceans, too, especially at the interface with the atmosphere, may also be very turbulent, and (4) water particles in clouds absorb CO₂ from the atmosphere, and then send that CO₂ into the oceans as acid rain (all rain is acid because of dissolved CO₂). It seems to me, therefore, absurd to suggest that our CO₂ emissions can just hang around in the atmosphere instead of moving into the oceans to maintain the equilibrium partitioning of ca. 50/1. Something else must be happening, and indeed it is — the oceans are warming.

The National Oceanic and Atmospheric Administration (NOAA) of the United States has a record of sea surface Ts of the oceans since 1880, and the NOAA graph below shows that warming started suddenly in earnest around 1905. There was a bit of a hiatus from 1945 to 1975, but then warming continued until the present day. Henry’s Law dictates that if the oceans warm they will release CO₂ into the atmosphere. Indeed, the equilibrium partitioning ratio of CO₂ between ocean and atmosphere will gradually reduce from the figure of 50/1 as CO₂ is released. I have called this “dynamic equilibrium partitioning”, because while Henry’s Law must apply, the heterogeneities in the ocean atmosphere system where water and CO₂ are being partitioned are considerable, and one can only look broadly at the Earth system as a whole. Never mind, we already do that sort of broad thinking when we talk about average global Ts, and so on.

Annual global sea surface temperature anomalies from 1880 to 2015 with superimposed linear trend (base period1951-1980), red positive, blue negative. http://www.ncdc.noaa.gov/cag/timeseries/global/globe/ocean/ytd/12/1880-2016.

If CO₂ is released from the oceans, this will counteract the movement of CO₂ from the atmosphere into the oceans (a buffering effect) and some of our emitted CO₂ will be retained in the atmosphere because of this buffering. The equilibrium partitioning ratio of 50/1 will reduce as the oceans warm, and it is easy to demonstrate that our emissions are so small compared to the total amount already in the entire ocean–atmosphere system that the increase in atmospheric CO₂ would be more-or-less the same regardless as to how much we emit. As noted above, if the oceans weren’t warming, our emissions would only have increased the amount of CO₂ in the atmosphere by 7 ppm. The fact that CO₂ has increased by 140 ppm is because the oceans are warming and expelling CO₂. Our emissions are hanging around in the atmosphere only because of the buffering effect. One may conclude, therefore, that the increase in the global average T of the lower atmosphere is because of the warming of the oceans, not our emissions.

4. The oceans

The oceans, which are warming, are very much capable of warming the atmosphere. This is immediately evident when major changes take place in the pattern of ocean currents. When the equatorial trade winds blow more strongly westwards from South America, they push the waters of the Pacific Ocean westwards, thus dragging up much colder water from depth along the S American coast and spreading those colder waters westwards into the Pacific. The surge of water westwards causes sea levels in northern Australia to rise, making it easier for the Great Barrier Reef to grow (coral reefs need space to grow upwards). This is the La Nina pattern, which is relatively cool because of the upsurge of cold deep Pacific water. When the trade winds are less strong, much less cold water is drawn up, the Pacific Ocean to the west of S America becomes warmer again (now called El Nino), and sea levels fall in Australia, making life more difficult for the corals, bringing them closer to the hot sun, and perhaps leading to bleaching. During a strong El Nino, global lower atmospheric Ts rise by ca. 1 °C in just a year or two, and then fall by the same amount very rapidly when El Nino stops. The 1 °C rise has nothing whatsoever to do with our emissions. Yet the climate alarmists still tell us that a 1.5 °C warming is dangerous, and that global warming over the last 100 years is unusually rapid. What rubbish both those statements are.

If we recognize the ability of the oceans to warm the atmosphere, it is hardly surprising to find that the graph of lower atmospheric global warming (next figure) almost exactly mimics the graph for the warming of the oceans (figure above). This suggests very strongly that the Ts of the lower atmosphere are directly linked to those of the oceans. This is not surprising, given that the oceans have a mass enormously greater than the atmosphere, and that water is remarkable for its unusually large heat capacity, enabling it to store huge amounts of heat. In contrast, the atmosphere is ill equipped to store heat, and it cannot effectively warm the oceans, as explained by Brendan Godwin (https://www.researchgate.net/publication/351436065_The_GHE_Theory_cannot_warm_the_oceans). The fact that average global sea surface Ts are between 20 and 21 °C, and that the average global lower atmosphere T is just 14 °C, also makes it unlikely the atmosphere can be warming the oceans.

Global monthly average surface air temperature since 1850 according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia‘s Climatic Research Unit (CRU), UK. The blue line represents the monthly values.

We all know from beach-side experiences that the air is barely able to make any impression on the T of the sea, and we all know that the direct light of the sun is immediately able to warm the oceans down to a reasonable depth. So why is it that the IPCC and climate scientists are obsessed with the atmosphere and not the oceans? Indeed, miffed by lower atmospheric warming not being as great as predicted in their models, climate scientists claim that the greenhouse heating of the atmosphere has been lost from the atmosphere to the oceans, causing their warming. I quote from a NOAA document on Ocean Heat Content “The ocean is storing an estimated 91 percent of the excess heat energy trapped in the Earth’s climate system by excess greenhouse gases”. It is strange that it is claimed the turbulence of the ocean–atmosphere interface leads to the transfer of heat from the atmosphere into the ocean, yet it is also claimed that CO₂ has to hang around in the atmosphere because there is insufficient activity at that interface. Strange, too, that the atmosphere is supposed to heat the oceans, despite being significantly cooler on average than the oceans. And also remember it is yet to be established that CO₂ is a potent greenhouse gas (we still don’t know what CO₂ climate sensitivity is).

Furthermore, it is noteworthy that the graph of upper sea-level temperatures from NOAA (second figure up above) shows a very sudden and rapid rise of Ts from about 1905. Apart from the hiatus in T rise from 1945 to 1975, the graph shows a more-or-less constant rate of increase in T. How could that possibly be if warming was due to greenhouse-gas heat from the atmosphere? — because back in 1905 our emissions were small. If greenhouse-gas heating were responsible, one would expect the increase in T to start very gradually, and to be much more rapid as one approaches the present day.

So what may be heating the oceans if not the greenhouse gas heat of the atmosphere? The sun is the most obvious answer. Climate scientists now reluctantly accept that the 100,000 year cycles of glaciation and interglacial over the last million years are primarily due to changes in the amount of heat derived from the sun, due to Milankovitch cycles, the main one of which is the 100,000 year cycle of changing distance of the Earth’s orbit from the sun. Closer to the sun, an interglacial, further away a glaciation. Nevertheless, the obsession with CO₂ continues with many climate scientists suggesting the Milankovitch effect is very slight, and that the slight initial heating drives CO₂ from the ocean, and that this CO₂ then warms the atmosphere due to the greenhouse effect, and that the atmosphere then warms the oceans further leading to more CO₂ escape. Sounds like a chain reaction, but no it can’t be, because the warming eventually stops, and the CO₂ is miraculously absorbed again by the oceans, which are cooling into the next glaciation. This complex explanation is implausible when compared to the simpler and more logical explanation that the cycle of warming and cooling is completely the result of the Milankovitch cycle, which first brings Earth closer to the sun, causing ocean heating and exsolution of CO₂ from the warming seas, and which then causes Earth to retreat from the sun, cooling the oceans, thus enabling them to absorb the CO₂ again as Earth enters another glaciation (just to remind everyone that a cold ocean will dissolve more CO₂ than a warm ocean).

What may be the cause of modern warming, if it is not due to the greenhouse effect of our emissions? Again, I would point to the sun first and foremost. There are four different Milankovitch cycles, depending on (1) distance of Earth from the Sun due to eccentricity of its orbital path (ca. 100,000-year cycles), (2) tilt of Earth relative to the orbit (41,000-year cycles), and (3 and 4) precession (25,000- and 112,000-year cycles). The 100,000 year cycle operates because it moves the Earth closer then further away from the sun. The other cycles may result in more ocean being exposed to the sun, and they would reinforce each other if they became effective at the same time. I’m not aware of any deep investigation into whether or not the minor cycles may now be reinforcing the warmth of the present interglacial. This needs to be done (but not by me!!). Another option for increased warmth is a change in cloud cover. It has also been suggested that an increase in volcanic activity beneath the ocean surface could be a cause of heating. Opponents of that idea say that there is simply not enough volcanism taking place, but this does not properly take into account the fact that there is 65,000 kilometres of mid-ocean ridges in the oceans, and magma (which would be ca. 1,000 °C) is almost constantly being emplaced, or cooling off, in a zone that extends downwards several kilometres below the ridges themselves. This activity is often not accompanied by obvious lava eruptions on the ocean surface, and we simply don’t have enough observations or details about the thermal effects of this cryptic activity, which may possibly be episodic.

5. Plate tectonics

Even if we abandon the idea that CO₂ is driving global warming, and instead look to the sun and the oceans for answers, we have not explained the major changes in climate through the Phanerozoic. Why three major periods of glaciation, including the present-day cold period? Geology would tell us that it is due to the distribution of continental masses and oceans on Earth’s surface. The present day glacial period can be related to the breakup of Pangea and later Gondwana. But first to the glacial period 300 million years ago. Supercontinent Pangea was formed at the end of the Carboniferous. My last research project was in NW France, where my French colleague Gérard Bossière and I proposed that the huge transcurrent faults of Armorica possibly represent thousands of kilometres of sideways movement along the collision zone of Laurentia (which was made up mainly of the north America craton) and Gondwana, leading to the formation of the supercontinent Pangea. Indeed, the positioning of Pangea over the south pole led to a major glaciation because warming of the polar region by the oceans was simply not possible.

Pangea eventually broke up with the opening of the Atlantic Ocean, and later Gondwana broke up with Antarctica becoming separated from South Africa, Australia, and India. Antarctica was positioned over the south pole, and the Arctic Ocean at the north pole became almost completely surrounded by continental material, isolating it from warmer ocean currents. Once the Drake Passage opened between South America and Antarctica, the Southern Ocean, swept along by the roaring forties, developed the circum-Antarctic current, which effectively isolates Antarctica from the warming influences of ocean currents coming from the tropics. Hence the development of the present-day bi-polar glaciation.

The Ordovician glaciation of 450 million years ago corresponds to a time when most continental masses encircled an ocean at the south pole, again inhibiting the warming of the polar area by warm ocean currents. Interestingly to me, some of the drop-stone deposits of that glaciation are found in NW France (Armorica), where I conducted my most recent research.

The greenhouse gas effect of CO₂ is pretty-well irrelevant to these arguments. Although measuring CO₂ past levels is more difficult than measuring past Ts, there is a clear tendency for there to be more CO₂ in the atmosphere when Earth is warm,  and less when Earth is cold. The climate activists argue therefore that the warm periods are due to the high greenhouse gas concentrations in the atmosphere. But there are three problems with this. First, one has to ask where did the CO₂ come from (a question seldom answered convincingly), secondly, we must remind ourselves that we don’t know if CO₂ is a potent greenhouse gas, and thirdly, there is the much simpler explanation that plate tectonics controls climate, and that when Earth warms up CO₂ levels in the atmosphere rise because it is expelled from the oceans, in accordance with Henry’s Law.

Certainly, everyone must be aware that climate change is normal for Earth, has always been taking place, and has never previously needed our emissions (hardly surprising, given we’ve only been around for a few 100,000 years).

6. Politics and climate activism

We are, as they say, all like sheep when it comes to fashion, cults, politics, and religion. I had believed that science didn’t suffer from this sheep-like behaviour. Unfortunately, not today. The sheep are all bleating “The science of climate change is settled”. Just goes to show that sheep are not scientists and do not understand the first thing about science. Science, by definition, is never settled. With regard to today’s politics and activism, I had never expected the science of climate change to become the focus of so much skullduggery and simple dishonesty.

Consider first what the scientists of the IPCC in the Assessment Report 6, Chapter 11, write on pages 1583–1585: “… there is low confidence in observed long-term (40 years or more) trends in TC [tropical cyclone] intensity, frequency, and duration, and any observed trends in phenomena such as tornadoes and hail; … it is likely that the global frequency of TCs will either decrease or remain essentially unchanged, … there is low confidence in projections of small-scale phenomena such as tornadoes and hail storms; and there is medium confidence that there will be a reduced frequency and a poleward shift of mid-latitude cyclones due to future anthropogenic climate change.”  

The following table from Assessment Report 6 summarises this low confidence in any human influence on most aspects of climate change up to the present day.

Table 12.12 | Emergence of CIDs in different time periods, as assessed in this section. The colour corresponds to the confidence of the region with the highest confidence: white cells indicate where evidence is lacking or the signal is not present, leading to overall low confidence of an emerging signal.

Then contrast that with what is written in the Assessment Report 6 in the Summary for Policymakers (written by politicians):“Human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has strengthened since Assessment Report 5.”

How dishonest is that?

Then consider the following from The Club of Rome, which acts as a Think Tank and Climate Consultant for the United Nations: “The common enemy of humanity is man. In searching for a new enemy to unite us, we came up with the idea that pollution, the threat of global warming, water shortages, famine and the like would fit the bill”. Is this what has led to the world being taken over by climate alarmists, who exaggerate, distort, and falsify what is happening with climate change? And corrupt science in the process.

Then Christiana Figueres, the Executive Secretary of the UN’s Framework Convention on Climate Change said: “Our aim is not to save the world from ecological calamity but to change the economic system….This is probably the most difficult task we have ever given ourselves, which is to transform the economic development model for the first time in human history”.

Then from IPCC official Ottmar Edenhofer: “One has to free oneself from the illusion that international climate policy is environmental policy. It is not. It is actually about how we redistribute de facto the world’s wealth”.

Then consider that even the respected Sir David Attenborough has been accused of indulging in what has been termed “noble corruption” (telling lies for the noble cause of tackling climate change), as described in forensic detail by Susan Crockford in her book “Fallen Icon”.

Time for the media to front up and tell everybody about what’s going on. Time to re-learn how to think and discuss, understand what science is (never settled), and stop acting like sheep.

7. What should we do about agriculture and methane emissions?

The following is taken from the Centrist NZ News Hub

NZ climate scientist Kevin Trenberth questions the scientific basis for stringent methane reduction goals and has challenged the widely held belief that these emissions significantly contribute to global warming. He says, in a comment posted to the Newsroom story, that the moral panic surrounding New Zealand’s emissions, particularly related to methane, is scientifically unfounded.

In Trenberth’s response to Daalder’s analysis, he contends that New Zealand’s agricultural methane emissions have already reached a state of net-zero impact on climate change. Trenberth’s argument centres on the notion that methane emissions from livestock are part of a natural cycle. He explains that the methane emitted by cattle and land use basically represents a re-release of carbon dioxide that was temporarily stored in short-term grasses. This cyclical process, according to Trenberth, does not result in a net harm to New Zealand’s carbon dioxide targets. “The issue is that methane is so short lived that, in fact, NZ is already at “net zero” (with regards to) methane. The numbers of livestock have been stable enough since 2010 so the amounts emitted are completely compensated by the amounts oxidised to carbon dioxide.”

“Since the methane started out as carbon dioxide in the atmosphere before being taken up in grass, and then eaten by livestock, the process is circular. The main issues with methane are fossil methane from mining operations,” he says. 

Trenberth describes the Newsroom analysis as “hokey” and that New Zealand’s stable livestock numbers since 2010 have led to a balance where the methane emitted is offset by the amount oxidised to carbon dioxide.  Trenberth correctly points out that there are fewer livestock today than there was back then, further strengthening the argument that New Zealand methane emissions are already at net zero.

Kevin Trenberth is a well-known distinguished climate scientist, originally from Christchurch NZ, and now retired back to NZ. Given that he has always supported the idea that CO₂ is an important driver of modern global warming, it is particularly significant that he is willing to speak out about the nonsense of trying to control the methane emissions of livestock. NZ government take note.

8. What comes next, climate wise?

Regardless as to what is forcing the present-day warming of the oceans, be it the sun and Milankovitch cycles or submarine volcanic activity, Earth will cool down again. If plate tectonics are the basic cause of the present-day glacial period, we will not escape from the present-day cold until Antarctica moves away from the south pole, and/or the circum-Antarctic ocean current is disrupted, and/or the Arctic Ocean is opened up to warmer ocean currents. Given that none of those things are likely to happen any time soon, I fear that we are destined to follow the 100,000 year Milankovitch cycle into another intense glaciation. I have argued that our emissions are not at all responsible for the slight warming we are experiencing. We can emit as much CO₂ as we like. It will not stop us entering that glaciation. That’s very very bad news, because all of Canada, most of northern Europe will become completely uninhabitable, and worst of all, CO₂ contents of the atmosphere will plunge to dangerously low levels (but all that is probably 80,000 years away, when the height of the next glaciation is reached, and when sea levels are again 140 metres lower than today). If CO₂ levels in the atmosphere fall below 150 ppm all life will probably be extinguished. That’s the existential danger we really face (but not in our children’s or grandchildren’s time!!).

Because they are finite resources, we must try to cut back on our use of fossil fuels, but there is no rush, and we could build the odd coal-fired power station whilst we decide how to provide enough energy and manage our resources in a more sustainable way. Forget about reaching net zero, forget about becoming a vegan to save the world, and stop telling our farmers how to manage the emissions of their livestock.