Water contributes to all three of the global warming categories outlined above; water vapour is a greenhouse gas; water plays a vital role in Photosynthesis; and, it contributes to the heat effect both through the albedo effect of clouds and oceans and through evapotranspiration.

All Animals exhale water vapour in their breath.

“The major contributor to increases in radiative forcing due to increased concentrations of greenhouse gases since pre-industrial times is CO2 - 61%; CH4 - 17%; N2O - 4%; CFC's -12%. Stratospheric water vapour increases, which are expected to result from methane emissions, contribute 6%, although evidence for changes in concentration is based entirely on model calculations.” (JT Houghton: GJ Jenkins and JJ Ephraums 'Climate Change. The IPCC Scientific Assessment' Cambridge University Press, Cambridge 1990 p.45).

Ice sheets reflect sunlight back into space and therefore help to cool the Earth.

The Carbon spiral contributes to the climate through the release of Carbon emissions - whether through the burning of Trees, the decay of Phytomass, Animals’ exhalations, volcanic eruptions. All of these emissions boost the supply side of the Carbon spiral, the greenhouse effect. Carbon also contributes to the Photosynthetic effect, the demand side of Carbon spiral.

Oceans .. “have less than 1% of the biomass of total land plants. Except at the continental margins, life in the oceans is spread very thin.” (Lawrence E Joseph ‘Gaia. The Growth of an Idea’ Arkana, England 1990 p.143).

“Undisturbed soil holds even more carbon than there is in the form of trees.” (John Gribbin ‘Hothouse earth’ Bantam Press 1990 p.115).

“Today, the amount of soil carbon is about 40 times greater than the level of carbon in the atmosphere.” (Jon Erickson ‘Greenhouse earth. Tomorrow’s Disaster Today’ Tab Books, Blue Ridge Summit PA 1990 p.4).

“Martin Hoffert observes that even though the biomass of the oceans is but a tiny fraction of that on land, oceanic biota contribute almost as much in the way of total chemical production as do land organisms. Pound for pound the organisms of the ocean are as much as one thousand times as productive as those on land.” (Lawrence E Joseph ‘Gaia. The Growth of an Idea’ Arkana, England 1990 p.144). He doesn’t say which chemicals but presumaby he means Carbon and oxygen.

.. “wood decay fungi are instrumental in releasing around 85 billion tonnes of carbon (as CO2) into the atmosphere each year.” (Global Biodiversity. Status of the Earth’s Living Resources’ Edited by Brian Groombridge Chapman and Hall London 1992 p.51).

“Undisturbed soil holds even more carbon than there is in the form of trees. Up to half of the original carbon content of the soil must oxidise slowly into CO2 and escape into the atmosphere as land comes under the plough. This must have been a major contribution to the build up of CO2 in the atmosphere in the 19th and early 20th centuries.” (John Gribbin ‘Hothouse earth’ Bantam Press 1990 p.115).

“About half of the energy converted into chemical form (through photosynthesis) is used in the metabolic processes of the photosynthesizing plants themselves. It is made available through the process of respiration, which involves the uptake of oxygen and the release into the atmosphere, or into the surrounding water, of about half of the CO2 and water initially taken up in photosynthetic process.” (Stephen Boyden ‘Biohistory: The Interplay Betweeen Human Society and the Biosphere. Past and Present’ Paris and the Parthenon Publishing Group Carnforth Lancashire 1992 p.20).

This concerns the way Carbon is removed from the atmosphere.

“Northern forests is of great significance in the annual transfer of the carbon resources of the biosphere. Each year there is a spring growth spurt in the Northern Hemisphere, much of which occurs in the boreal forest, which is so important that it affects the carbon cycling in the atmosphere of the whole planet.” (E G Nisbet ‘Leaving Eden. To Protect and Manage the Earth’ Cambridge Univesity Press Cambridge 1991 p.43); “Data buried for years in forestry ministries have lent new weight to the theory that the planet’s northern or ‘boreal’ forest has played a key role in damping down the greenhouse effect. According to the records, over the past half century, the forest has soaked up huge quantities of excess carbon dioxide. The Science and Policy Associates said the boreal forest is crucial for controlling atmospheric CO2. Jorge Sarmiento of Princeton University has estimated the sizes of terrestrial CO2 sources and sinks. Between 1920 and 1976, forests and other plants soaked up 35 million tonnes of CO2. .. from 1976, the amount of CO2 absorbed in the ocean and staying in the atmosphere equalled the amount released. Land plants had apparently started giving off as much CO2 as they absorbed. The turning point, 1976, was the same year .. that the boreal forests slipped from net growth to net depletion.” (New Scientist 11.9.93 p.6).

.. “algae process approximately half of the the earth’s supply of carbon ..” (Lawrence E Joseph ‘Gaia. The Growth of an Idea’ Arkana, England 1990 p.127); “It has been estimated that 40% of the carbon fixed by photosynthesis on the Earth is carried out by algae and cyanobacteria, especially those in oceans and seas.” (Global Biodiversity. Status of the Earth’s Living Resources’ Edited by Brian Groombridge Chapman and Hall London 1992 p.51).

“In 1957 .. Roger Revelle and Hans Suess, working at the Scripps Institute of Oceanography in San Diego .. found that the oceans absorb only 50% of the excess carbon dioxide produced by man.” (Anita Gordon & David Suzuki ‘It’s a Matter of Survival’ Harper Collins London 1991 p.11).

.. “many kinds of bacteria, not just photosynthesizers, actively remove and use carbon dioxide and make chemical compounds from it.” (James Lovelock ‘The Ages of Gaia. A Biography of Our Living Earth’ Oxford University Press 1988 p.83); “Soils may also be contributing in removing methane (from the atmosphere) to the tune of 15-45 million tonnes each year.” (Anil Agarwal & Sunita Narain 'Global Warming in an Unequal World. A Case of Environmental Colonialism' Centre for Science and Environment India 1991 p.10). It is the Micro-organisms in the soil which extract Carbon from the atmosphere.

Large quantities of atmospheric Carbon are simply washed out of the atmosphere by water vapour creating Carbonic acid which then falls as rain.

Forests are capable of storing Carbon for many decades and some species can store Carbon for centuries. A few species can store Carbon for a millenium.

“The concentration of CO2 in the mixed layer of the ocean, the top 250 feet, is as much as the entire atmosphere itself. In this region of the ocean, microorganisms use the carbon dioxide in the form of bicarbonite to make their skeletons and shells. When the animal dies, its hard shell or skeleton settles on the bottom of the ocean where it contributes to the formation of carbonate rock. If the calcium carbonate falls to greater depths, it is dissolved in the cold deep waters of the abyssal. The abyssal region, by virtue of its great volume, holds the vast majority of free carbon dioxide. Due to upwelling of CO2-rich waters from the deep ocean ...” (Jon Erickson ‘Greenhouse earth. Tomorrow’s Disaster Today’ Tab Books, Blue Ridge Summit PA 1990 p.139). The importance of this analysis of the carbon spiral it suggests that the deposition of shells is not as permanent a process as many commetators believe because some of the CO2 is pushed up from the sea floor.

It is sometimes suggested that atmospheric hydroxyl radicals are a sink for methane. This is true but they are not a sink for Carbon since the hydroxyl radicals create water and Carbon dioxide.“Methane is primarily removed by a reaction with hydroxyl radicals (OH) in the troposphere. This reaction represents a sink of about 400-600 million tonnes per year.” (Anil Agarwal & Sunita Narain 'Global Warming in an Unequal World. A Case of Environmental Colonialism' Centre for Science and Environment India 1991 p.10).

John Elmsley (talking about the greenhouse effect, as distinct from the much more comprehensive concept of global warming) has pointed that, “Air contains 350 parts per million (ppm) of CO2 but this pales into insignificance compared to water vapour which ranges between 1 and 4 per cent (i.e. 10,000 to 40,000 ppm) depending on temperature and humidity. According to Keith Beyer, MIT, water accounts for 99% of the greenhouse effect.” (New Scientist 17.10.92 p.53-54).

Although global warming seems to be caused overwhelmingly by the water cycle some commentators believe it is the concentration of Carbon in the atmosphere which determines changes in global average temperatures. Water seems to provide the ‘base load’ which generates the bulk of the Planet’s warmth whilst the concentration of atmospheric Carbon seems to determine the small, marginal, variations in temperatures which have such a considerable impact on the Earth’s climate. However, as has been noted above, the theory of the greenhouse effect is in considerable dispute and to give atmospheric Carbon such an important role seems to be unwarranted.