30 October, 2010
“Man has lost the capacity to foresee and to forestall. He will end by destroying the earth.” Albert Schweitzer
“Climate is essentially an emergent property of life’s interaction with its immediate environment.” Peter Bunyard
Just as cancer cells appear to have no awareness that they are committing suicide by killing their host, we are doing the same in respect to Gaia. Although we have not found a cure for cancer, I do hope that Gaia will be able to find a cure for her form of cancer.
I’ve written this because I think that we are getting our climate change information in short bursts of controversial statements and media hype.
“A greater obstacle to public communication has arisen with the politicization of reporting of global warming, a perhaps inevitable consequence of the economic and social implications of efforts required to alter the course of human-made climate change. We have the impression that the effect of politicization on communication of the science is aggravated by the fact that much of the media is owned by or strongly influenced by special economic interests.
The task of alleviating the communication obstacle posed by politicization is formidable. The difficulty is compounded by continual attacks on the credibility of scientists. Polls indicate that the attacks have been effective in causing many members of the public to doubt the reality of global warming.” (Hansen, 2010)
The books that I am familiar with on the subject, although written by highly qualified scientists, such as James Hansen, in my estimation, miss important aspects that would serve to fill the gaps left by the media. In this chapter, which is not intended to tell the whole story, I hope to tie up a few loose strands and fill in some gaps usually ignored by the typical news item.
Anthropogenic carbon emissions have altered natural climate cycles for the last several thousand years in gradual increments. As more and more of our species left hunter gathering groups and engaged in agriculture, our footprints deepened. Forests were cleared for agriculture, housing, war machines, weapons and shipbuilding and many other purposes. Forest destruction has persisted to this day and previously massive rainforests are threatened with total destruction with no hope of natural regeneration as the poor soil is depleted for export crops such as palm oil and soy beans. Parallel with this destruction we are seeing a population increase that is totally out of control. It seems that many people believe they have an inalienable right to have as many children as they choose without regard whatsoever for the Earth’s carrying capacity. There appears to be no serious discussions world wide directed toward seriously limiting human population. Do we really have an energy crisis or just feeling the results of runaway population growth? The rise in population and the rise in temperature and atmospheric CO2 follow the same upward trend locked into a regenerative feedback cycle. More people, more energy required, more energy expended, more CO2 not to mention unhealthy pollutants such as coal and diesel particulates. It is only since the Industrial Revolution and the development of monitoring technology that we have charts and diagrams that take temperature and CO2 out of the speculative realm to the home of certainty. It is a certainty that the percentage of CO2 in the atmosphere is higher than we have seen in at least the last 600,000 years and that humans are the major cause.
There can be no doubt that anthropogenic greenhouse gas emissions, such as carbon dioxide, nitrous oxide and methane coupled with carbon particulates from brown coal fired electricity plants, contribute significantly to the greenhouse effect that has inhibited the sharp drop in global temperature seen in the past 3 or 4 interglacial periods. The graphic picture of the global temperature pattern revealed by the Vostok and EPICA (Antarctic) earth-core samples, resembles an upside down icicle of warmth for around 8,000 years followed by around 110,000 years of cold (known as ice age). This upside down icicle depicts a very quick rise, very sharp peak and a very sharp fall of 2 to 3 degrees centigrade within less than 10,000 years before gradually settling into an ice age of nearly 10 degrees colder than the peak in around 10,000 more years.
Click here for a good visual of the Vostok findings
Click here for the antartic core samples visual
Humans are obviously an important part of nature, but since our ecological footprint has only been really significant for maybe 5 out of the last 10,000 years, I think we need to ask: How did the Earth manage to sustain itself before we arrived on the scene?
Humans have dangerously stifled the planets natural means of regulating itself. Gaia maintains a balance of forces using its life-forms and weathering process. A few life-forms vary the amount of reflected sunlight, atmospheric CO2 and O2 content, whilst others sequester carbon. The ocean absorbs vast amounts of C02 but less and less as its temperature increases.
Glacier melt re-mineralizes the soil after each ice age. There is an amazing array of self-regulation behaviours too lengthy to delve into here. However, our present and recent past global growth economy is destroying these mechanisms. It is obvious that the fate of the Earth and our fate intermingle, for actually, as was proposed in previous chapters, we are the Earth and we are thus committing suicide.
Being at the top of the food chain does not mean that we can now assume Earth management responsibilities.
Several knowledgeable and well-meaning authors have written about how we should be stewards of the Earth. A first thought might accept this idea but with more reflection, I suggest that it is an extremely dangerous anthropocentric view of our presence. Stewardship means “responsible planning and management of resources.” This view is dangerous simply because we have not the wisdom and understanding to control and manage “nature”, the word we use for the aggregate physicality of Gaia. We must play in tune with Gaia’s rhythm or be selected out of the orchestra.
So it has been hot before
Climate change sceptics never tire of stating that the Earth was warmer millions of years ago. Be that as it may, we can forget about how the planet was 65 million years ago for the purpose of determining how our industrial pollution affects the present. Yes, the planet was far warmer and there was over 10 times the amount of atmospheric CO2 around. Why Gaia evolved to a series of cyclical glacial and interglacial periods is beyond determining with the instruments we have on hand and thus beyond our understanding. We must begin to appreciate that Gaia may just know what she is doing. Perhaps the long glacial periods are necessary to counteract the increased warming energy of the sun. Again, we don’t know. Of course, if we continue to look upon the planet as a piece of machinery that can be rebuilt and controlled, than there is very little hope for us. Gaia is a living organism which we live in and function as part of. Living organisms are complex and Gaia even more complex. Regardless of how the planet was 65 million years ago or 2 billion years ago, we have to work with the present extent of earth’s evolution. Of course climate varies. However, our advances in scientific instruments and ability to read the past from soil and ice core samples reveals that our present interglacial warming half cycle varies significantly from the past in two primary ways. Atmospheric CO2 is steadily increasing and higher than ever recorded in the last 750,000 years and although we are overdue for a cooling trend, global temperature has increased around one degree centigrade in the last 140 years. It is appropriate to question why average temperature is increasing, but a far more important and largely ignored question is: Why have we not begun the steep cooling trend seen in the Vostok core sample graph shown in the graph below?
The graphic below shows clearly that the knife point shaped rapid drop from the peak has not happened this time. Instead of haggling over what has caused the rise in temperature in the last 150 years, we need to figure out why the temperature is NOT dropping.
My theory is that whereas there should be or have been in the past, billions of trees all sucking up carbon, humans have destroyed them and thus eliminated Gaia’s major negative feedback mechanism or temperature dropping factor.
Our intensive agricultural system might appear to be taking their place but consisting primarily of annuals, our crops of seeds ie: maise, rice, wheat, barley, oats, millet, quinoa etc. leave massive amounts of carbon after harvesting that more easily and more rapidly release the sequestered carbon back into the atmosphere as CO2.
Trees also transpire and cause increased cloud cover which tends to increase the albedo more than it increases the greenhouse effect. Of course, we have lost that also. As I have explained further on, one of the major Melankovich cycles, obliquity or tilt has been favouring a cooling cycle over the last eight thousand years. Over the next few thousand years it will move back to favouring a warming trend and we may have missed a major trigger for global cooling.
And now some background information. I’m afraid that many people think that climate is completely unpredictable and entirely erratic. This is not true. Let me explain why.
Why the heating effect from the sun varies
The fundamental driver of atmospheric temperature is, of course, the sun. The amount of heat felt on the Earth’s surface is dependent primarily on the angle of incidence of sunlight. Obviously, with a sphere, the greatest heat is absorbed at the center of the globe if and when the globe lies in a plane perpendicular to the sun. The heating effect tails off as the angle, of incidence, [the angle formed by the input rays and the reflected rays when the sun’s rays are not perpendicular] increases and the sun’s rays are spread out over a greater area. At an angle of 30 degrees, for instance, the sun’s rays are spread over an area double to that of the perpendicular and thus the heat generated is only one half. Calculating the heating effect of the sun, called insolation, is much more complicated and variable due to three aspects of the earth’s juxtaposition to and orbital path around the sun. The following explanation is limited to just an introduction. Full understanding requires detailed diagrams and more precise information than I am able to impart in this chapter. The details are truly fascinating and are fully and clearly explained on the web at: http://en.wikipedia.org/wiki/Milankovitch_cycles.
There are three major physical factors that affect insolation and it is only their synthesis which varies insolation enough to trigger the significant rise or fall of global temperature that results in the recent glacial/interglacial cycles with a period of around 120,000 years.
Basically, the equator only receives maximum energy transfer (when the sun’s rays are perpendicular) twice a year because the earth is tilted. It is this tilt – called obliquity – which causes what we call the seasons. The northern hemisphere, for instance, receives a lesser incidence angle during what we call summer and greater during the winter. The tilt also varies slightly (from 22.5 degrees to 25 degrees) in a cyclical manner that either favors warming or cooling in both hemispheres but always opposite to each other.
This can be tricky to visualize. You might push a stick through a small ball of something soft so it sticks out at both ends. Color one end of the stick blue, for instance and name it the North Pole and the other, South Pole a different color. Hold it in one hand and tilt it around, for example, 30 degrees. Then hold a somewhat bigger ball in the other hand that represents the sun. Tilt the stick so that the North Pole is tilted toward the sun. You can see that at the beginning you have maximum summer at the North Pole and maximum winter at the South Pole. Move the tilted ball 180 degrees and you’ll note the opposite effect. At the 90 degree and 270 degree points around the sun you can see the equinoxes where the tilt has virtually no effect.
Click here for an interesting graphic on obliquity
The factor that amplifies both warmer and cooler conditions is the shape of the earth’s orbit around the sun. You may know that something that is “out of round” is often called eccentric. The Earth’s orbit is not only eccentric, but the amount of eccentricity varies over time in a cyclical manner. During the thousands of years when the orbit is more circular, the intensity of the seasons is less because the Earth is closer to the sun at both the closest
Click here for an interesting graphic on eccentricity
and farthest extent of the orbit. The opposite, of course, holds true when the orbit is more eccentric.
The last, most difficult to grasp factor is called precession. My simple explanation for purposes of this discussion is that since the Earth is not perfectly round, it does not spin like a fast moving top but wobbles slightly.
The effect of this wobble on our climate is subtle. You may need to study precession more deeply elsewhere to fully grasp the concept. Wobble not only adds or subtracts to the amount of tilt, but means that the beginning and end of the seasons don’t hold to the same geographic location around the Earth during the precession cycle. The reason being that wobble changes the maximum and minimum extent of tilt so that the equinox points are not synchronous with our solar based time. How might that affect insolation? The start of winter at X geographical position, for instance, makes a complete cycle approximately every 23,000 years. (Note that none of the Earth’s orbital cycles are of equal duration over a period of many cycles.) If winter occurs in the northern hemisphere over mostly land and the Earth’s orbital position is near the farthest point from the sun, then these winters are colder and thus enhances the build-up of ice. If this is synchronous with a cooling effect out of the other two factors mentioned above, then it is likely that the planet will remain in an ice age.
Again, the opposite or interglacial period, may occur where warm winters are in synch with a warming effect out of the other two factors.
Click here for an interesting graphic on precession
It is how the orbital cycles line up with each other
Since the period of all three of these cycles is different, they are constantly aiding and opposing insolation. The Melankovich theory is that when they move into an aiding position, they trigger the start of an interglacial period and when the shortest period decreases enough, they set up a condition favourable for a sudden decrease in insolation and average global temperature. The resultant cycle is around 120,000 years and
Co-relates favourably with ice core samples. Of course, as in most scientific theories, there are detractors who wish to trash the whole idea. One only needs to consider the numbers of people, including scientists, who don’t accept the theory of evolution. One reason for this is that factors such as absorption of CO2 by trees, clouds formed because of transpiration by trees, variations in the amount CO2 being held in the oceans, snow cover, the numbers of phytoplankton, the amount of dimethyl sulphide and more must figure into the equation. With so many variables, all global warming theory is open to criticism and those oppose will bring their ulterior motives into the picture.
There is more to the story
As if there were not enough variables to contend with, I must add that cyclical variations in air and ocean currents are affected by orbital forcing explained above and in turn also affect the amount of heat absorbed.
Scientists, particularly Professor Andre Berger, have been able to plot the various orbital cycles and produce a table going back a million years. This table also contains insolation figures. Thankfully, the tables are available for download from the internet. An analysis of the tables reveals two rather worrying facts which due to the complexity of the material that I have tried to throw some light on above, have not been explained by the media.
One, the event that should have triggered a cooling cycle – minimum tilt that favours a cooling trigger – has passed its nadir and is now increasing. Another nadir is not due for another 40,000 years.
Two, eccentricity is now nearly as low as it ever been in the last million years and will become even lower for the next few thousand years. So the Earth’s orbit is almost circular. This means that the past reinforcement and coincidence of cycle overlaps that have triggered colder winters and global cooling, for instance, will be missing for many thousands of years.
Professor Berger proposes that we will not see another ice age for many thousands of years.
“Today’s comparatively warm climate has been the exception more than the rule during the last 500,000 years or more. If recent warm periods (or interglacials) are a guide, then we may soon slip into another glacial period. But Berger and Loutre argue in their Perspective that with or without human perturbations, the current warm climate may last another 50,000 years. The reason is a minimum in the eccentricity of Earth’s orbit around the Sun.” (Berger, A. and Loutre, M., 2002, pgs 1287 – 1288)
Much of the climate change literature points out that the adverse (adverse to life-forms like humans) conditions such as increased desertification, flooding of coastal lowlands such as Miami Beach and Bangladesh may occur regardless of our efforts to cut down on anthropogenic greenhouse gas emissions. Perhaps they read Berger and Loutre above.
So how are humans connected with the variations of orbital factors?
You might well point out that these factors taken simply as stated operate regardless of the human actions. Yes, but this is not the whole story.
Next we must briefly consider both how much of the sun’s energy is reflected back out into space (referred to as albedo) and how the variations at the earth’s surface, some materials not only vary in absorption capabilities but also hold heat longer than others, plus the content of the various layers of the atmosphere effect global temperature. As most of you know, our atmosphere impedes the escape of reflected sun energy by further absorbing and reflecting back heat. We have named this the greenhouse effect. Without this property, the earth’s temperature would be perhaps 30 degrees cooler and life as we know it would not be possible. Our scientists, armed with sensitive instruments, have documented the heat energy absorptive properties of the atmospheric gasses, aerosols, and especially carbon particulates from diesel and coal fuels. Climate sceptics like to point out that water vapour is the strongest greenhouse gas. So what? We can’t drink ocean saltwater but fish live in it. What’s the point?
To put it simply, we are upsetting the balancing and regulating capabilities of the living Earth by emitting such a large volume of greenhouse gasses, that their heat absorption capabilities have increased the greenhouse warming effect dramatically. Regardless of the arguments of climate skeptics, there are just no other factors other than anthropogenic that would account for the resulting rise in CO2 and average global temperature. A graph of both CO2 and Global temperature over the last 600,000 years reveals that they are virtually synchronous. Our media has had a circus day describing the possible results of excessive global warming. Enough has already been said so I’ll not go into that subject. I suggest that overall, the IPCC has underplayed the tune and understated the possibility of runaway global warming.
The Real Questions
The media has drawn our attention away from what I suggest is the real question. So, we have global warming and that is a problem. We have identified several factors above that are causing the temperature to rise. However, I think we are blind to the most significant question:
What, given the factors we have identified and considering Gaia’s ability to self regulate over time, does Gaia have available to reverse the warming if we continue with our industrial expansion?
As we saw above, The Melankovich cycles favour cooling to their maximum extent yet our interglacial period has not come to an end. I support Dr. James Hansen’s suggestion that we may well skip the next ice age. If we do, will the Melankovich cooling factors overcome the warming factors that are still present 120,000 years from now? If not, then how hot will the Earth be?
So what? You may still feel that since the Earth has been a lot warmer in the past there is nothing to be concerned about. Yes, but don’t forget that the sun is constantly growing in volume and putting out more heat. Dr. James Lovelock’s Gaia Theory was prompted by his dismay over how much cooler the earth had stayed relative to the effect of the increase strength of the sun’s energy over the last 2 to 3 billion years. Lovelock and Harding have listed and explained the various positive and negative feedback mechanisms that come into the forefront as Gaia self-regulates. Obviously, Gaia’s efforts have brought us to where we are now which resulted in incredible diversity and growth as polar ice diminished. Not only have humans caused a major drop in diversity and increase in extinction, but our technology and economic system of expansion based on Earth’s resources have set up atmospheric and oceanic conditions outside the parameters we have studied in the last 600,000 years. Although we certainly cannot answer the question above, we can attempt to discover what resources were available let’s say 120,000 or so years ago at the end of the last interglacial period.
At the beginning of each interglacial period as the ice receded from the land, vast numbers of trees spread north and performed a carbon sequestering service. They also released water vapor which stimulated cloud cover that increased the albedo effectively taking the place, as far as albedo is concerned, of the miles and miles of ice that had melted. With that negative feedback firmly in place and the orbital forcing factors favouring cooling, the downward cycle of Gaia’s temperature was assured and triggered the end of the interglacial period.
As I have pointed our already, unfortunately for all, these natural feedback factors been destroyed by humans. Millions of trees over thousands of years have been chopped to build armadas and commercial shipping, other war implements, and shelter for humans as if they were useless to anything other than to serve the greed of humans.
“Apart from he profligate burning of fossil fuels and releasing the earth’s long-term carbon and energy storage depot that has taken millions of years to lay down, deforestation has been the main contributor to the increase in carbon dioxide in the atmosphere that has resulted in global warming.1 Energy capture and storage is absolutely essential for the survival of the planet, just as energy capture and storage is necessary for the survival of individual organisms.” (Ho, M. W., 2008, pg. 81)
That’s why I emphasize that we are asking the wrong question perhaps too late. How will Gaia halt the present positive feedback loop? Could it be the halt of the Atlantic Current because of the rapid melting of northern ice? If the Atlantic Ocean cools sufficiently to absorb enough CO2 to counteract the other positive feedbacks, then possibly global cooling will be triggered.
We have James Lovelock to thank for prompting research into how the Earth self-regulates its temperature. How severely have we weakened Gaia’s ability to self-regulate effectively? When and if Gaia achieves temperature stability, what kind of environment will we have to adjust to? We simply cannot answer these two questions. We don’t know and we don’t even know if we can ever know. No sane gambler would play a game with such dismal odds. Perhaps our leaders are insane.
1 Ho, M.W. “Oceans and Global Warming” Science and Society 31 (2006b): 11-13
Ho, M.W. “Global Warming is Happening” Science and Society 31 (2006c): 23-24
Bunyard, P. Gaia, Climate and the Amazon, 2005, Independent Science Panel