THE CO2 DEBATE
The discussion and analysis here should be readily understood by most readers, but some of the theory and interpretation behind the discussion might require some understanding of relatively low-level chemistry.
The stable forms of carbon at the Earth’s surface are:
Carbon dioxide CO2, bicarbonate ions in solution HCO3-, carbonates (calcite, limestone etc).
These three are the most oxidised and therefor the most stable forms of carbon at the Earth's surface.
Other forms of unstable carbon are more reduced and include methane (CH4), carbon monoxide (CO), elemental carbon its self, and living matter. All of these will ultimately oxidise to one of the more oxidised variants in the presence of an oxygenated atmosphere.
CO2 is the most oxidised form of carbon, forming a stable relatively inert gas in the atmosphere (less than 400 ppm). Bicarbonate (HCO3-), is the stable form dissolved in water, which contains 60 times more abundant CO2 than does the atmosphere. Carbonates are the stable solid form, mainly as calcite (CaCO3 or limestone) and dolomite (CaMg(CO3)2 another form of limestone). Limestones are 44% CO2 by weight and form a major rock type, often entire mountain ranges. More than 99% of all the CO2 component formerly in the Earth’s early atmosphere is now locked up in carbonate rock.
Certain trace gases in the atmosphere are thought to maintain the Earth’s temperature at a fairly constant level. These gases are called greenhouse gases & have the effect of preventing incoming visible radiation escaping as infrared radiation. The trapped radiation wave lengths heat up the atmosphere at the surface, but only to a limited extent, dropping off dramatically as their abundance increases (see later comments).
The mean global temperature of the Earth is a warm 15 degrees C . Without these greenhouse gases, all infrared radiation would be lost to space and the global Earth temperature would be considerably lower overall with hot days and very cold nights. Without the atmosphere the Earth’s mean surface temperature would be -18 degrees, rather than the present average of 15 degress. Variations in greenhouse gases are thought to influence climate, & in the present climate debate CO2 is the greenhouse gas of principal concern.
The main greenhouse gases, their abundance, their thermal influences & the contribution by man are presented in the following table.
Ranking of greenhouse gases vs CO2 in terms of global heat generation capacity:
GREEN HOUSE GAS Heat retention potential (multiple)
Carbon Dioxide (CO2) 1
Chloroflourocarbons (CFC’s) 1,300 TO 9,300
Methane (CH4) 21
Nitrous oxide (N2O) 310
Water vapour (this does not include water droplets as in clouds) is a powerful greenhouse gas comprising about 95% of the greenhouse gas inventory & is by far the dominant influence, but does not contribute to what is called the enhanced greenhouse effect because it is not increasing in abundance.
A runnaway greenshouse effect is said to occur when increasing greenshouse temperatures are enhanced by positive feedbacks in the environment that also generate more greenhouse components or other forms of atmospheric temperature increase, (eg increasing water vapour) thus accelerating and exacerbating the climatic effect. Positive feedbacks are however more than compensated by buffering effects which act to minimise any change in systems at equilibrium.
Pre industrial revolution levels 1750-1800 1990 levels
CO2 280 ppm 353 ppm
Methane 0.8 ppm 1.72 ppm
CO2 dissolved in the ocean is some 60 times that in the atmosphere with more than 85% as bicarbonate ions (HCO3-).
Human activity (fossil fuels & burning biomass), has caused much of the increase. Volcanic gases also produce large amounts of CO2. Burning all the fossil fuels in existence would produce an atmospheric CO2 level of around 2000 ppm. To halve the present levels would probably annihilate all terrestrial vegetation & animal life. Decreasing atmospheric CO2 would be far more disadvantageous than increasing it. Methane is sourced through rice cultivation, ruminating animals, coal mining, natural gas venting, & inefficient biomass oxidation.
95% of warming due to greenhouse gases comes from water vapour in the atmosphere (not water droplets as in clouds), and only 0.28% from human additions. Human activity accounts for about 6% of the non-water vapour component.
Atmospheric CO2 levels over time
The chart below displays the cyclical variations in atmospheric CO2 determined from ice core samples over the last 400,000 years, showing the ”hockey stick effect”, & the remarkable regularity of CO2 increases & reductions following 100, 000 year cycles. If CO2 causes temperature increases, what caused these regular cycles of increasing CO2 lasting about 100,000 years? If however the temperatures where cyclical (due to Milankovitch-cycle style planetary orbit, tilt and wobble variations), and the CO2 variations followed temperature changes (not driving them), this would account for this phenomena.
This zig-zag pattern suggests we are about to descend into a 100,000 year global cooling event.
Far more significant CO2 and temperature versus time charts across all of geological time are presented and discussed in much more detail elsewhere.
FACTS about CARBON DIOXIDE
Of the 186 billion tons of CO2 that enter earth's atmosphere each year from all sources, only 6 billion tons are from human activity. Approximately 90 billion tons come from biologic activity in earth's oceans and another 90 billion tons from such sources as volcanoes and decaying land plants.
At 382 parts per million, CO2 is a minor constituent of earth's atmosphere—less than 4/100ths of 1% of all gases present. Compared to former geologic times, earth's current atmosphere is CO2 impoverished. During the Ordovician-Silurian glaciation (450-420 million years ago), atmospheric CO2 was more than 4000 ppm, but did not contribute to any warming. During the Jurassic-Cretaceous glaciation (151-132 million years ago), atmospheric CO2 was more than 2000 ppm and again did not contribute to any warming. If CO2 drives climate, why were there glaciations and not a runaway greenhouse effects during these events?
The effect of increasing levels of atmospheric CO2 on plant growth and animal health.
The photo below shows a comparison of plant growth achieved in atmospheres of differing CO2 levels. This readily displays the fertilizer effect of increased levels of atmospheric CO2. The numbers in the photo's indicate the amount of additional CO2 that has been introduced into the atmosphere, and the numbers below the total atmospheric CO2 cotent in parts per million.
The table and chart below display the dramatically decreasing greenhouse warming effect of increasing CO2 levels in an atmosphere, a point that is often lost when increasing CO2 levels are being discussed in the media. The data suggests that plants are seriously starved for adequate CO2 for healthy development and optimum growth in the present atmosphere and that significant agricultural productivity may be gained in this area if atmospheric CO2 levels can be substantially increased. Optimal levels of atmospheric CO2 may be around 1000 ppm for many plant species.
Plants exposed to higher levels of CO2, not only grow more vigorously , they require less water (less evapo-transpiration from smaller stomata required to get adequate CO2). They can grow in drier climates and produce higher yields on smaller acreages. Limiting growth factors such as higher usage of nutrients such as nitrogen, zinc, iron etc (as exist for today''s plants) can be accommodated, as they are today, with fertilizers, supplements and management practices. There are likely to be pros and cons, with increased CO2 levels, but plants thrived under these conditions in the past, they don't need to adapt to new conditions, and they manage on less water and in drier conditions. Even the small man-made CO2 contributions (about 140 ppm), over the last 50 years or so have dramatically greened the earth (see CSIRO global map below).
CO2 & Human Health.
CO2 is odorless, colorless, tasteless and slightly heavier than air. Plants absorb CO2 and emit oxygen as a waste product. Humans and animals breathe oxygen and emit CO2 as a waste product. Carbon dioxide is a nutrient, not a pollutant, and for all life, plants and animals alike it is an essential requirement. Atmospheric CO2 is an essential plant fertilizer not a toxin. All animals get their carbon from eating plants, or eating other animals that eat plants. The effect of increased atmospheric CO2 on humans appears minimal at any likely concentrations, even up to 1% (10,000 ppm). Human exhale CO2 at levels of around 38,000 ppm from their lungs, suggesting that even at these levels there is no serious toxicity as long as here is adequate oxygen available for normal respiration.
Coral reefs and CO2
CO2 gets into the atmosphere originally through volcanic eruptions. Once in the atmosphere it is continually recycled by terrestrial plant life (through the process of photosynthesis), animal life, the earth's oceans (in the form of the bicarbonate ion, HCO3-), and eventually into calcite (limestones, coral reef structures, marine shells & skeletons), and carbon energy reservoirs of coal, petroleum & gas. The oceans contain more than 60 times as much CO2 as the atmosphere and are in equilibrium with marine limestone deposits.
The great retirement home for most terrestrial carbon dioxide is in limestones (44% CO2 by weight), and they make up a considerable proportion of surface and subsurface rock sequences, including all the worlds coral reefs and entire mountain ranges in many parts of the world. Coral reefs are made of CO2 and would not exist without CO2. The coral organisms themselves derive all their cellular carbon from CO2 sourced from bicarbonate ions extracted from the oceans, but ultimately derived from he atmosphere.
The carbonate forming chemical reactions depend on the two equilibrium reactions involved:
(1) CO2 + H2O <----> HCO3- + H+ (acid) at the atmosphere-ocean interface
(2) HCO3- + Ca2+ <----> CaCO3 + H+ (acid) occurring in shallow warm oceans
The overall combined reaction is:
(3) CO2 + H2O + Ca2+ <------> CaCO3 + 2H+ (acid)
Note that although these reactions are equilibrium reactions, the equilibrium strongly favors the reactions moving the the right in each case and downward in the sequence through 1), to 2), and the ultimate removal of all CO2 from the atmosphere, and all HCO3- from the seas, to from voluminous limestone. Eventually all the world''s carbon and all the world's CO2 will end up in limestones, (see later section), and none will be available to maintain or form any life on Earth.
Note also that for each molecule of calcite (CACO3) produced (or molecle of CO2 consumed), two hydrogen ions (H+, read acid) are produced, contributing to ocean acidification. Coral reefs themselves are responsible for much of the worlds oceans acidification, although no one is suggesting that we should eliminate coral reefs in order to reduce ocean acidification. Atmospheric CO2 when dissolving in the oceans to produce bicarbonate ions (HCO3- reaction 1 above), does increase ocean acidification, but the removal of bicarbonate ions to form coral reefs and other limestones (reaction 2 above) produces even more acid.
CO2 in the oceans and ocean acidification
There is about fifty to sixty times as much carbon dissolved in the oceans as exists in the atmosphere. The oceans act as an enormous carbon sink, and have taken up about a third of CO2 emitted by human activity. It has been estimated that the uptake of anthropogenic carbon since 1750 has led to the ocean becoming more acidic with an average decrease in pH of 0.1 units.
No mention that coral reef formation as a major cause of ocean acidification, or that hundreds of millions of years when atmospheric CO2/acidification was much higher yet did not cause a problem.
The pH of the ocean is around 8.0 (mildly alkaline). The introduction of hydrogen ions in the above reactions causes the ocean pH to lower and become less alkaline. It does not become more acid as the H+ ions immediately react with excess OH- ions and neutralize. Only when the pH is lowered below 7.0 will the ocean become acid and have an excess of H+ ions. Introducing H+ ions at pH 8.00 will make the ocean less corrosive (less caustic) and increasingly more neutral until pH 7.0 is reached. The use of the term ocean acidification is a misnomer until the pH drops below 7.0, which is unlikely in the present circumstances because there are enormous pH buffering reactions with geology (rocks), countering the lowering of pH to anywhere near pH 7.
Another contributor to lowering the oceans pH is rainwater. Pure condensed water has a pH of 7.0, but rainwater has a pH between 5-6. Even compared to sea water, pure water is more acid, and rain water far more acid again. Every time fresh rainwater enters the Coal Sea from Queensland flood events it contributes substantially to ocean acidification of the reef environment. We never hear this being stated in ocean acidification discussions, or the fact that coral reef growth itself increases acidification.
Many of the low-lying island nations concerned about rising oceans may not realize it but it is the continued growth of coral limestone and its essential CO2 component that formed their island nation in the first place and is keeping their island nations above sea level now and has been for centuries. The reactions above are ultimately responsible for all the worlds coral reefs, all the worlds limestones, dolomites and marble rock sequences including entire mountain ranges and landscapes, all the worlds carbonate shellfish, and all the worlds calcareous soils.
Atmospheric CO2 and climate change
Global warming began 18,000 years ago, accompanied by a steady rise in atmospheric carbon dioxide. The correlation of CO2 with temperature appears clearly demonstrated. But correlation does not always mean causation.
What caused this phenomena is a matter of ongoing debate for some. Clearly, though, global warming and rising CO2 levels in Earth's atmosphere started long before the industrial revolution.
In detail there are some surprising contradictions. Time lines (in the red ellipses in the diagram below), reveal that the relationships are not always synchronous or positive.
In the highlighted red ellipses there are both positive and negative correlations between temperatures and CO2 levels which should not happen if CO2 is driving temperature. The warming rates are ten times the cooling rates and occur over much shorter periods.
In the Vostok ice core data, if gain and loss of CO2 is the cause of warming and cooling, it is difficult to understand where the CO2 is coming from, and going to, in this period in the past on such regular cycles unless the cooling and warming episode came first and are followed by CO2 changes. The rapid warming rate versus the much lower cooling rate also is telling us something.
In this instance it appears that if temperature increases first (due to orbital forcing), followed by a delayed change in atmospheric CO2, as CO2 is released (on warming), or reabsorbed (on cooling), in the ocean. This causes an additional feedback affect on temperature with two separate pulses of temperature resulting with a recognizable delay. The temperature should be seen to increase first, followed by an increase in CO2 and further temperature feedback. .
However if CO2 levels increased first, temperatures should rise appropriate to the atmospheric CO2 concentration, (with some internal feedback) and a new equilibrium temperature would be eventually reached. There would not be two distinct pulses separated by a delay period. In this case the CO2 should be seen to increase first followed by temperature. Both this and the previous scenario can occur but should be distinguishable.
It appears more likely that increasing temperature in the oceans causes increased levels of CO2 to form and to be released into the atmosphere. It is well known that increasing ocean temperatures decreases bicarbonate levels in the ocean (closer to the equator), favouring more CO2 in the atmosphere and more limestone production, while at the same time lower temperature towards the poles favour increasing CO2 solubility in the oceans as bicarbonate ions (HCO3-). This means that there is an atmospheric flow of CO2 from the equator to the poles, and a counter flow of bicarbonate ions in the ocean towards the equator. On approaching the equator, as the oceans warm, some bicarbonate converts to CO2 and escapes into the atmosphere to be recirculated, and some reacts with abundant soluble Ca2+ to be permanently removed from the system in the form of limestones, including coral reefs, according to the following chemical reactions.
The chart below displays what appears to be a delayed response between an initial temperature increase and a responding atmospheric CO2 increase, possibly of the order of hundreds of years. This delay, if long enough, could then cause the crossover effect of the two trends displayed. This should not otherwise be possible.
Global CO2 Versus Temperature Across the Geological Time Scale
The extremely revealing but rather busy chart below displays the relationship of both temperature (as seen on other charts) shown in red, and also atmospheric CO2 levels (in blue), across geological time. The relationship between CO2 levels and the temperature can be seen to be totally inconsistent, varying from being a positive association, to periods where it was entirely antipathetic.
During the massive decrease in CO2 over time the mean global temperature has not changed significantly, largely remaining at about 20 degrees (a few degrees warmer than at present). This is yet another demonstration (if one was necessary) that atmospheric CO2 (man-made or otherwise) has not consistently influenced global temperature at any stage in Earth history despite a massive decrease (95% reduction) and did not pose and existential threat during that period.
The reason that CO2 is rising is that atmospheric CO2 levels are now so low (having progressively naturally declined over 90% over earth history to present starvation levels), that the very low man-made CO2 contributions (of a few 10's of ppm/year), are now registering. This is an indication of how perilously low atmospheric CO2 actually is. We need to actively restore hugely beneficial CO2 levels by burning fossil fuels. Global vegetation is currently starved of adequate CO2 (around 1000 ppm), for optimum growth.
This chart in particular and the other global temperature versus geological time charts displayed in this web site, completely contradict the popular climate change models advanced by climate alarmists where CO2 is purported to dive temperature.
The man-induced atmospheric CO2 model appears to have arisen solely as there seemed no other possible explanation for observed warming. No one it seems amongst the cream of world climate science considered the possibility that it might be normal and reflected in the longer term climate history. A history that seems to have been entirely ignored . It appears that IPCC scientists and other climate catastrophists were either entirely ignorant of this information, that has been around for more than 40 years, or chose to ignore it and not reveal it. Either way it displays an appalling lack of quality science by some of the world's leading scientists who have claimed scientific purity and superiority on this issue, howling down those with contrary views for many years.