Many think the world just too big and the atmosphere too huge for us to be able to change the climate, but the oceans are more enormous than the atmosphere and we can show they have been changed by man’s activities, so why not the climate?Through this series of papers, designed to be easy to read and understand, we will sometimes use technical terms so we can better understand articles that might use them, but they will always be accompanied by explanations. And there is one other issue for us all: if you were reading the book you would all know the context in which each Part of this Series is to be understood, but in this format I need to explain that context. In order to tackle the question here we need first to see the scientific information that led me to even ask the question.
The Background Information
When I first studied the published plot of the last 470,000 years of temperature and CO2 from the Antarctic Vostock ice cores, I was astonished to note the apparent correlation (similarity) between the two plots which are shown below. They seem to track one another almost exactly, but could it just be coincidence? Bizarre if it is as they are very similar, so I set out to try to explain as much of these plots as I could. If I found, and could then explain, that they do and must track one another, I would have established something really useful, as knowing why our climate has cycled might tell us much about where it is probably going.
This Chart is well published and well used so this is NOT new information, and was in one format in Al Gore’s film ‘An Inconvenient Truth’. When he used it he was not focussing on what I am here but on the relative concentration of carbon (CO2) in our atmosphere now. He went up on a fork truck beside the plot to bring attention to the vertical plot of carbon relative to the history:
I admit the chart is a bit confusing as it zigzags all over the place, but while many things did strike me, I wondered particularly what had been going on recently – where the blue temperature plot decided not to peak as it did during all previous warm periods. It seemed and seems to be hovering at our current temperature while the carbon figure was the same as during all previous peaks. That is definitely odd as the temperature ought to be higher if it was still doing what it has for a very long time. Something seems to have changed. To highlight this ‘event’ I have simplified it below, circling the area that interested me:
I have only shown the 5 peaks and ‘adjusted’ each warm period so the carbon levels are on the horizontal axis. It is a minor adjustment, but in this way we can better compare the temperatures reached during each peak, the tops of the blue plot now being directly comparable. I have followed the same colour coding as in the earlier plot so as not to confuse, but I wish the red line was the temperature! It isn’t, it’s the Carbon (CO2). There are three observations:
- It is extremely clear that our current warm period singularly failed to reach the same high temperatures the others did, which is the issue we are about to consider and hopefully explain.
- Through each previous peak the temperature quickly crashed from its peak, while during this one it is staggering about, neither going solidly up or down. And it has been broadly doing that for more than 10,000 years.
- You may have wondered where the 2° (or 2½°) comes from to reach the point where we lose control of climate – called ‘The Tipping Point’. As you can see the temperature has been higher before by about that amount so that is where it comes from. If we pass it, the planet will be in new temperature territory and events will happen that may leap our climate to much greater temperatures that we would then have no control over. It is deadly serious, and the word ‘deadly’ is used advisedly as we should understand from the First Paper in this series. One question is ‘Have we already pushed our atmosphere to a point where it is anyway taking us through that barrier?’ This is another question we will address in a later Paper.
Interesting isn’t it? And now you know what we are looking for you can refer back to the full chart and see what I mean. It seemed as if our temperature has sort of ‘flat-lined’ for around 10,000 years, but that couldn’t be down to we humans because the industrial revolution didn’t start at all until around 250 years ago, so what was going on?
The trouble is this chart didn’t give me the detail I needed in order to be able to see what was really happening, so the only solution was to get the original raw data. The scientific community are enormously helpful – they are not trying to hide anything – and quite quickly I had the full data, all nearly half million years of it. I recognised this put me in a privileged position, so set to work to plot it. It did take a long time (not a simple ‘read and plot’) and the chart I finished with extends to about 8 metres. I have to walk around it to see what was happening, but during the analysis I learnt something interesting that we will just cover here as I ask you NOT to try to match the carbon with the temperature for date. The dates really apply only to the temperature. If you are OK just to accept that, you don’t need to read the next paragraph which explains why. If you would like to know why, please read on.
It is relatively easy to date the temperature as various isotopes act as temperature markers, so if we can date ice at a particular depth (not at all simple) the isotope will give us the temperature for the year recorded at that depth. But CO2 is a gas, and gas bubbles in the ice have to be used to work out what the CO2 concentration was for that year’s ice. But that is where it all gets much more difficult. You see, ice is porous, so gas migrates through it very easily when it is fresh snow, but it even migrates through very dense ice. The gas (air) in the ice that is quite deep is the same as it is at the surface. This means the CO2 at that depth is only what it is today, so the isotopes in the ice at a point give the temperature for that date but not the CO2 concentration. That is for a much younger year! The layer of ice through which the gas migrates is called the ‘Fern Layer’, which covers thousands of years but also varies with time. Interestingly I have never read any article from any journalist that explains this or takes it into account. A quick reason to mistrust most newspaper articles, TV reports and films. If you don’t understand this – you don’t understand enough to push your views on others.
So now let’s look at the detail, which I believe is the first time this has been generally published. First the warm period around 324,000 years ago: The Blue plot is temperature; the red is the carbon (CO2) but don’t forget not to read the dates for the carbon:
Both the carbon and temperature rise almost continuously to their peaks where after a short time – they decline again. We will explain what is happening through this period and why they don’t continue upwards in a later Paper, but for now can I say Carbon will surely react faster than temperature – but even temperature is heading firmly down just 2,000 years after still heading sharply up, and the peak itself lasted a mere 1,000 years. Now the next warm period 238,000 years ago:
A dramatic illustration of just how sharp the warm peaks have been. In this case the peak itself lasted diddlysquat years, before which the upward gradient was sharp as was the downward gradient after it.
That leaves only the warm peak around 130,000 years ago before the one we are in:
Yet again the temperature plot spends only around 1,000 years pretty much at its peak, with yet again the gradient being steep on either side of a 2,000 year period.
So going back more than 100,000 years, when modern man was just beginning to walk the planet and near leaving Africa – the climate cycles were much of a muchness as you can see. Now let’s look at the current warm period in exactly the same way with no skulduggery. Are you ready for what may be a surprise?
Wow! How different is this? A complete contrast and clearly not what has happened before.
Remember, I plotted this from the raw data – just a very very long list of numbers on countless pages, so this plot unfolded before my eyes. I would suggest this is conclusive evidence that, for whatever reason, the natural climate cycle has long since gone and that the actual climate departed from the natural cycle some 11,000 years ago. At this point I would like to make one extraneous but very relevant observation:
While we don’t yet have an explanation for the strangely oscillating temperature plot over the last 11,000 years we see above, it is clear it spends as much time crashing down as rushing up. Now consider what the climate sceptics argue – “it has all happened before – it is the natural climate cycle”. Had they troubled themselves to get the real data before speaking, they would have discovered it has not indeed “all happened before”. And the media have worked with them because they don’t understand it either and aggressive argument brings the audience to the media.
The sceptics take an insignificant period of time to “show” that temperature isn’t affected by carbon and “it is all the natural cycle”. As you can now see, I could take countless examples where the two are moving in opposite directions – if I took an equally insignificant period of time. Perhaps my observation at the start of Part 1 of the series, when I said of the media “Snippets of information and misinformation are spread liberally and regurgitated to suit the objectives of the next writer – and that the media has an ability to give undue air time and column inches to those with little if any knowledge but a lot to say” is already proved, but there is so much more coming.
The climate doesn’t change on a whim – that much is abundantly clear from the earlier plots if not the last one – and anyway it clearly cannot. Something caused it to change and one great facet of my approach is that the climate did change; there is a reason – we just have to work out what it was. No small task and countless hours of thinking, mostly in 3 dimensions, but what a challenge.
What follows is an excerpt from the book – one section from the Chapter ‘CLIMATE HISTORY – An Explanation’ in which we may find what caused the climate inconsistency over the last 10 to 12,000 years.
Why did our planet not warm as could be expected through the last 8,000 to 10,000 years?
We can see from the history of climate that even though the carbon dioxide level reached about 265 parts per million about 8,000 years ago, the temperature stubbornly stuck about 2.1° below where it should have settled for that level of carbon, and has broadly stayed there. Now why would that be? What could have caused that? 8,000 years ago was before Stonehenge, so we didn’t mess it up – did we. Or did we?
The history over the previous more than ½ million years shows it should have risen by something like that 2.1°. Yet it didn’t. So the fact of the matter is there must have been some reason why.
One truism is that throughout history the climate has done what it did for reasons that we may not yet always understand. But every feedback; everything we understand about climate; everything we partly understand; and everything we don’t yet even either understand or realise had an impact – changed our climate. This was the reality. So can we discover the reason why that temperature behaved strangely?
I thought about this on and off for absolutely ages. What was happening 8,000 to 12,000 years ago that hadn’t happened before? Then one night I woke with a start. Of course! It must be! Or perhaps not… Could it affect the climate?
The Development of Agriculture
Let’s look at the timeline for the ‘progress’ of agriculture shown against the current warm period:
Interestingly we see that through this period of time and only through this period of time, man started adopting agriculture, the earliest dates for this being between about 12,700 and 11,400 years ago when we know we began to cultivate grain in the Middle East. This transformed human life, surely as nothing before or since, so the practice spread quickly.
The Timeline above shows what we know of the spread of agriculture but we also need to know what they were doing to know how much land they used. Along with growing the grains, (Emmer and Spelt as the original wheats and millet) – the first animals (dogs, sheep and goats) were also being domesticated and these changes allowed man to become sedentary, settling rather than roaming as hunter gatherers: now we could produce our food where we lived and not have to travel far and wide. As we could produce substantially more food we could now live in one place. And being able to have certainty of supply allowed us to be more sociable and live in much bigger groups. Instead of living in temporary shelters we could now live in huts where our offspring were much safer and easier to look after. Importantly it allowed the population to expand very significantly and quickly. Then about 10,000 years ago pigs and cattle were added as domesticated animals.
As with all other animals (we are actually no different) our human population depends on the food supply – increase that and population goes with it. The historic adoption of agriculture was the first event allowing our population to grow quickly but the most recent example is what we call ‘The Green Revolution’ starting in the late 1940’s. The introduction and widespread use of fertilisers, pesticides and herbicides allowed a food explosion – and guess what – the population exploded with it.
It isn’t difficult to understand that if you double the human population, and they averagely only all live as well as before, you double the consumption of absolutely everything from timber products through food, clothing, energy and transport to water. Everything. The person attributed with leading or ‘inventing’ the green revolution is Norman Borlaug who was given a Nobel Peace Prize for his work. The argument was that his work had saved countless lives, yet the fact is that he had allowed the global population to explode. In 1944 it was 2.2B – and his revolution expanded it to the current 7B – or it has more than tripled already. If we now think our planet is being severely damaged by the consumption of the current population, we ought to ask the Nobel Peace Prize committee what new work or invention would now qualify for the Peace Prize?
But back to agriculture, and the green revolution allowed poor land that was previously left for the environment to be brought into food production for a single species – Homo Sapiens – us. It therefore also caused the further destruction of the global forest.
Now we need to understand what the adoption of farming involved.
Starting with the wheats, the original plants had a number of benefits over modern ones. They are much healthier to eat, having a lot more protein and fibre, and being essentially original wild grains also thrive naturally so need little agricultural intervention to crop as well as they can. But it wasn’t as easy to harvest as modern wheat as the grains are smaller and lighter and they would have had to be handpicked – a very difficult job – clearly with part of the crop lost on the ground. There were no harvest combines even 2,000 years ago.
Here are the original grains compared with modern wheat:
The early plants certainly produced less per area cultivated than our modern intensively farmed wheats which can yield over 8 tons per hectare. Tests have shown that grown organically under perfect conditions today, spelt produces about 2¾ tons per hectare. They were therefore unlikely with their primitive methods to have produced more than about 1 ton and probably much less. Could be very much less. I guess we will never know the answer to that.
There would have been another problem as wheat doesn’t monocrop well – you can’t keep growing it successfully on the same land as it requires large amounts of nitrogen though low yielding wild Emmer and Spelt may have fared better. It is therefore likely the early farmers did what they do in the Amazon today where they ‘slash and burn’ moving on to virgin land after a few years because the yield drops quite alarmingly. A lot of land could have been cleared during those early few thousand years and far more than the size of the population first suggests.
Their early animals would also have required a lot of pasture, so relative to the size of their population a very large land area would have had to be converted to agriculture. A lot of that early virgin forest must have been cleared by those early farmers over the few thousand years we are interested in. We mustn’t forget they had a lot of time! So now let’s look at the spread of agriculture.
This map shows where agriculture had already spread to by 6,500 years ago. Or put another way, it was becoming the norm even then. So one thing is for certain: the period of the growth of agriculture coincides exactly with the period the climate has left its historic track.
But enough of the history, which is all very interesting but we are trying to understand past climate aren’t we? What has all this got to do with it? We need to be patient, as before we can continue we now need to consider something quite different.
The sun shines on the surface of our planet, but as the Earth maintains a relatively constant temperature over time, the amount of heat coming in must roughly equal the amount going back out. Or we would either be getting hotter or colder.
The Yellow arrows are the short wave radiation (sunshine to you and me). The big one arriving is the sunshine coming in and the smaller one leaving the surface is what is reflected. But a warm body emits heat (think radiator or wood burner) which is actually in the long wave so the brown arrow leaving the surface is heat being radiated back out to space. It is the difference in wavelength that allows modern double glazing to work!
When we look at how Greenhouse Gases work, they only absorb the long wave so don’t affect the incoming solar energy but do ‘trap’ the heat being radiated – but that will be covered in another Paper coming soon.
The amount arriving is almost constant, but the amount leaving depends on how much is reflected and radiated back out from the surface. As the world warms it will radiate more [which is actually a negative feedback] but the amount radiated depends only on the surface temperature so is also almost a constant and has been over the last 11,000 years – or the period we are focussing on. But the amount reflected depends absolutely on the colour of the surface. Fact. Change the surface colour and you change how much is reflected. We all know that fresh snow reflects a lot (snow blindness) whereas mud doesn’t. Why do we need sunglasses in a snowy environment? It is because the surface is reflecting rather than absorbing the light (and heat).
Let’s look at the reflectivities (approx.) of a few different but relevant colours:
The figures above give the % of incoming radiation reflected away from the planet and as a rule the lighter the colour the greater the reflectivity. Instantly we can see the simply enormous variation from ‘nearly all the heat is retained’ to ‘nearly all is reflected away’.
I think you will find this surprising, but allowing me some tolerance on finding the right colours for this Document – there are some important ones above. The total range is from an extreme black which will reflect only around 2%, to a pure white which reflects over 95%. This is why the Arabs wear white!
Now let’s link the spread of agriculture with reflectivity
The problem is that different surfaces on the Earth have different colours and therefore different reflectivities. This is a topical issue in climate due to the melting Arctic Ice: As the area of Ice declines and ocean increases – a reflectivity of 86% is is replaced by one with only 10% (see above). We already have 2.5M sq kms less summer sea ice than a few decades ago and as the ice melts the Artic temperature increases even faster – which melts even more ice – even faster – etc. [Called a positive feedback]. The amazing image on the right shows the relative colours of the ice and the ocean in between the ice. All photos in this section courtesy of Yann Arthus-Bertrand from his book ‘Earth From the Air’.
But we aren’t talking about ice melting are we? No, but any and every change to the surface colour of our planet changes its ‘Albedo’ [reflectivity] which therefore changes the amount of solar energy retained, which therefore changes the temperature of Earth. We know that before agriculture, the land through much of the world was forested and forests are actually very dark in colour and this surface has a very low reflectivity. Forests reflect only around 7% to 12% depending on their colour viewed from space, so almost all the sun’s heat is retained. The photo on the left shows the colour of virgin forest – quite dark isn’t it, seen from above.
Converting land to agriculture though doesn’t just involve a simple change in reflectivity but a double whammy as we will see.
The First impact of agriculture on reflectivity (and therefore our Planet’s temperature).
Agriculture removed and removes the forest cover or natural vegetation and replaces it with surfaces that often change regularly throughout the year. Some time after harvest and before the new crop appears (usually in spring) the surface will be the soil which has its own colour depending on its makeup – anything from a sandy yellow through the browns to the reds – see below. All these reflect more than the forest did with the sandy soils reflecting the most.
Now we come to spring and as the grain starts to grow the land changes to a pale green colour. This reflects more than the forest but depending on the colour of the soil – more or less than that. But now we come to the really important time – the ripening and harvesting period. The land changes to a pale golden yellow colour which lasts for about a couple of months, after which the stubble is the same colour. During this time the reflectivity is much higher – and this makes the planet cooler.
Different soils and field colours
Cognac in France with wheat at harvest time and a vineyard below the wheat
Rice fields in various stages of growth and harvest
The photos above show an amazing array of colours and therefore reflectivities with each space changing colour through the year.
To put the scale of the effect into context, a ripe or stubble field reflects about 8 times as much as did the forest (60% against 7%). It is a serious change in solar heat retention and seriously reduces the temperature on Earth.
Clearly man has changed the surface colour beyond recognition with almost all changes causing the surface to reflect more heat away – which has cooled our world. But if we refer back to the Timeline image, we see quickly that in the early days of agriculture, during the first about 4,500 years until about 7,500 years ago, man farmed almost exclusively in the southern part of the northern hemisphere. He extended it gradually north over the next 1,000 or so years. So let’s look at the radiation arriving over the area in question:
Ah! We can see that changing the surface and therefore the reflectivity over the southern region had about twice the cooling effect of changing it over the northern region. So for each hectare brought under cultivation in the south the impact was the same as for 2 hectares in the north. Man’s early farming therefore had the biggest effect possible, so even though the population wasn’t large, they had a disproportionate impact.
We have already considered the impact man’s domination of the land has in the northern Rift Valley, and of course if the early farmers really damaged the land they farmed it would possibly have turned to desert or other arid lands further increasing the reflectivity. Remember that Egypt was a verdant land a few thousand years ago, not the desert it now is.
Is there any practical proof of the increased reflectivity of farmed land? Well, yes actually, from a sport where you absolutely must understand how, why and where the air moves. Gliding. Gliders have a horrible tendency to try to get back to the ground (called gravity!!) and the pilots only stay up because they find air that is moving upwards. If you don’t find this – down you come. Pilots have to understand where they will find rising air (just as many birds have to), and in the middle of summer you DON’T look for it over fields full of ripe wheat or stubble*¹. (Glider pilots please note: this is a simplistic statement but this book is about climate not flying).
But we just mentioned ‘doubly interesting’ so what else is there?
The Second impact of agriculture on reflectivity (and therefore our Planet’s temperature).
The amount of solar radiation arriving isn’t a constant with latitude but nor is it through the year. It maximises in the middle of summer when the sun is highest in the sky and reduces through to its winter minimum. And this is true everywhere. On our latitude in mid-summer we receive about 6 times as much solar energy as in mid-winter, so what is happening to the surface in summer matters hugely more than in winter. Obvious, but it needs to be said.
It is the same for the southern hemisphere but as a small matter of fact (just to be totally correct) in the tropics the solar radiation peaks twice a year: the sun is overhead twice – not once. The effect due to land under cultivation is the same, but the impact is much greater because the incoming radiation is much greater.
Here is the double whammy. When grains are being farmed, maximum reflectivity occurs during the long hot summer months when the arriving radiation is at its maximum, and it remains highly reflective for most of the period that solar radiation is at its maximum. All through the final ripening and harvesting, and until the land is ploughed, it reflects most of what is arriving.
The winter soil effect isn’t anything like as significant as the harvest effect – but all through the year agricultural land will reflect more solar energy than the original forest would have done.
Let’s now sum all this up and these are facts:
- The history of climate over the last 15,000 years is as the plot shown earlier in the Paper and at the start of this section as the ‘Timeline’.
- Man developed agriculture starting about 12,000 years ago.
- He ripped out much of the forest and replaced it with land that had a much higher albedo (was much more reflective), or he replaced the natural vegetation if not forest.
- He did this first in regions having the highest impact on the amount of radiation being reflected.
- The crops he planted caused the reflectivity to be most greatly affected during the periods arriving radiation was at its maximum.
- The adoption of agriculture allowed the human population to explode (relatively) further increasing the impact.
- We have changed the total reflectivity of the planet over only the last 12,000 years.
- This has cooled the Planet.
- The period of time corresponds perfectly with the long period of temperature instability over the last 12,000 years.
I can think of nothing else whatsoever that could have caused the temperature of Planet Earth – our home – not to have risen as it clearly should have. So:
Man started affecting the climate not in 1850, with the start of the Industrial Revolution, but around 12,000 years ago, caused by the introduction of agriculture. This has reduced the temperature of our Planet by about 2½°.
This not only appears to explain one element of climate history, but it does much more. It shows that man altered the climate long ago, and a very long time before we thought we had. It also demonstrates that using climate data from this recent 8,000 year period is fraught with hazard as we have been affecting the climate in lots of ways, many of which we either don’t know or cannot fully quantify. Any argument that uses data from this period, including the immediate past, without taking account of what is in this paper – is invalid. Those putting these arguments forward are simply not in possession of the facts and cannot be taking account of the science.
We have shown that far from man being unlikely to be altering the climate, we have been doing that for thousands of years. Unquestionably. And this is where the 2° we hear about being the temperature rise before we pass that tipping point comes from. So that is man-made too! Yet even now there are those who wish to argue (based on incorrect interpretations of limited data sets) we are not impacting the climate. But there is more. When we think about it.
A warning on the true impact we are having on our climate and the global temperature
Even since 1850 – and faster the closer we come to today – we have been ripping out the global forest, and removing forest today has the same effect as removing it thousands of years ago. So while maybe our GHG emissions have been trying to increase the temperature, forest removal AND the growing desertification are between them have an opposite and cooling effect. In order to calculate the actual effect our rapidly increasing CO2 emissions are having, we would have to add the negative impact of changing surface reflectivity to the temperature figures we have.
This would seem to be an explosive position to find ourselves in as if agriculture from 12,000 years ago to 150 years ago (1850) cooled the Planet by about 2.5°, the ever escalating changes we have had since then must have had an accountable negative impact on it. This must then be added to the actual increase (about 0.8°) to get at what we are doing. And, of course, we cannot rip out the forests for ever as there isn’t a whole lot left, so the cooling is about to come to an end EXCEPT that desertification continues apace. But growing desertification is also reducing our food supply.
This matter is of the greatest urgency for mankind as I also hypothesise we are sleep walking into a disaster of our own making.
Food for thought I suggest.
And incidentally – we did mess it up!
Mostly written in 2007.