Tasmanian Times

The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. No price is too high for the privilege of owning yourself. ~ Friedrich Nietzsche

The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. No price is too high for the privilege of owning yourself. ~ Friedrich Nietzsche


The terrible consequences of deforestation

Bob Burton’s article posted on TT HERE: Who’d Pay for Rupert Murdoch’s Climate Change Skepticism? raises the subject of the role of water vapour in climate change. Other TT discussions have canvassed the REDD (Reducing Emissions from Deforestation and Degradation) proposals from Copenhagen. I would like to extend these discussions.

Some time ago, while researching climate change, water and land use policies as a political candidate, I came across an interesting article on this web site: HERE

“We believe if there is climate change – which is manifested regionally and consists of three only indirectly related phenomena; drought, extreme weather, and global warming – it is the result of deforestation far more than the result of human CO2 emissions. And with respect to deforestation and sea level rise, it is clear that deforestation, at least theoretically, has had a far more dramatic impact on sea level rise than construction of large reservoirs.

There is an extremely interesting website called “Ten Billion Acres,” (HERE) that advocates “reforesting planet earth for the sake of human survival.” They take the position, with detailed arguments that are at the very least thought provoking, that “were there enough Trees in the equation, Climate Change would not be occurring other than that which would be normal for the Earth’s and Oceans’ cycles during this Era.” “Ten Billion Acres” refers to the amount of deforestation experienced on earth in the last 500 years – accelerated in the last 150 years. We’ve verified these numbers – ten billion acres is approximately 15 million square miles or 40 million square kilometers – so how much land-based water was lost when these trees were cut down?

It is shockingly difficult to get online data on the water content of trees, but thanks to Google Books, there is a 1896 study available that documents the water content of a variety of representative species of trees through the cycle of seasons. The study is entitled “On the variation of water content in trees,” HERE by James Barkley Pollock of the University of Wisconson. And it is clear from the data presented that the water content of trees is at least 50%, averaged across all trees and all seasons.

If you assume, for a global average, a forest has one tree for every five square meters, and that each tree has 10 cubic meters of mass (you can roll that around, this average assumes a rather dense forest of rather small trees, but overall these are probably somewhat conservative assumptions), then with a 50% water content, land based water that’s been lost to the oceans through deforestation would total 40,000 cubic kilometers, 4x the water volume sequestered in large reservoirs. And this number is grossly understated, since trees also sequester water underground as well as play a crucial role in replenishing aquifers. So why aren’t sea levels much higher?

At the least, these calculations indicate we still understand very little regarding the global hydrologic cycle. The volume of subsurface water, and the impact of depleting these aquifers still requires significant investigations. Our conclusion is that once again, the emphasis on CO2, or reservoirs for that matter, is misplaced. We should be figuring out how to increase forest canopy, particularly in the tropics where deforestation has the most significant impact on rainfall, aquifer health, climate, and global atmospheric quality. And we should be figuring out how to restore positive inflow to every aquifer on earth, where negative drawdowns have been grossly unsustainable ever since the invention of the mechanized pump.”

Other research from Australia suggests that, since European settlement, more than 12 billion trees have been removed from the Murray Darling Basin. If we allocated an average 2 cubic meters for these trees (and I have no idea whether this is an overestimation or underestimation – can anyone assist?), then the amount of water stored in trees that has been permanently removed from the Basin would be about 12,000 GL.

For comparison, the total volume of water stored in all of Australia’s large reservoirs is about 80,000GL. The total water extracted from the Australian environment in 04-05 for irrigated agriculture was about 12,000 GL. The value of production from irrigated agriculture in the Basin for the same period was about $3 billion. See www.water.gov.au .

The biochemistry of photosynthesis provides that for every tonne of water stored in a living tree, 2.44 tonnes of carbon dioxide is removed from the atmosphere. So the 12,000GL of water lost to the Murray Darling in trees also equates to a lost potential of nearly 30 billion tonnes of carbon dioxide. At $30 per tonne of CO2e in a emissions trading scheme, that is about $900 billion of lost potential – 300 $years worth of agricultural output.

Tracking these calculations back to the value of the water embodied in the trees, every tonne of green tree embodies about $36 of stored water value. Historically, we have allocate no value to the water in decisions on log pricing, forestry and land clearing operations.

At last count, the Federal Government has allocated budgets of over $20 billion to various schemes aimed at staving off the water crisis in the Murray Darling Basin. Add to this the billions estimated to be needed to support programs aimed at reducing carbon emissions.

Putting all this together, surely there must be potential to combine greenhouse, water and land-use policy in Australia. Could we be using water as a proxy for carbon dioxide?

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  1. MariettaBurton18

    January 14, 2011 at 10:01 am

    If you are willing to buy a car, you will have to get the business loans. Moreover, my mother all the time takes a car loan, which occurs to be the most reliable.

  2. Ben Quin

    December 19, 2009 at 3:42 pm

    Gerry, we know that water vapour is the most abundant of the greenhouse gases. Skeptics often use this fact as “proof” that man-made emissions of carbon dioxide are not the cause of global warming.

    However, I am not aware of any public discussion that links water vapour with caculations of CO2e in proposed emissions trading schemes.

    One theme I am keen to follow is: how much water vapour could we sequester from the atmosphere and fix in the soil, aquifers and in trees for the long term (generating multiple benefits) and will this help cool the atmosphere? What is the value of sequestered water vapour compared with the other major greenhouse gasses – carbon dioxide, nitrous oxide and methane?

    Your discussion of ocean acidification indicates that this theme is pertinent for both terrestrial and oceanic systems. The production and extraction of biomass from the Oceans must be considered as part of the technical response to global warming. The energy potential of the swarms of jellyfish currently clogging up the sea of Japan may be provide an interesting case study.

    Ben Quin

  3. Philip Lowe

    December 19, 2009 at 10:25 am

    Gerry Mander,Brilliant!!!!!!!!!!!!!!!!!!!

  4. Peter Bright

    December 18, 2009 at 7:50 pm

    Gerry, thankyou for this information.

    Reference to Wikipedia reveals that the use of calories is no longer supported. Additionally …

    (a) The calorie is a pre-SI metric unit of energy. The unit was first defined by Professor Nicolas Clément in 1824 as a unit of heat. This definition entered French and English dictionaries between 1841 and 1867.[1] In most fields its use is archaic, having been replaced by the SI unit of energy, the joule.

    (b) The “15 degree calorie” is ≈ 4.1855 J and is the amount of energy required to warm one gram (that’s 1 cubic centimetre when the density of water is 1.000) of air-free water from 14.5 °C to 15.5 °C at standard atmospheric pressure (101.325 kPa)

    While I was studying physics we rounded the figure to 4.186 joules as that amount of energy required to raise one cc of pure water by 1 degree celcius. If local conditions change (eg on a mountain top) then that figure changes, too.

    Using these figures and the fact that 1 joule of energy is the application of 1 watt of power for 1 second, we can see that to raise a litre of water (1000 cc) by 1 degree C we would need 4,186 joules.

    As an everyday example, let us heat a jug that contains 1 litre of water from 20 C to its boiling point of 100 C. Let us assume that the jug element is rated at 2400 watts (the usual maximum power draw from our home power points) and that the jug’s insulation is perfect.

    How long would the process take?

    From the formula W (Work in Joules) = P (Power in watts) x t (time in seconds) we have

    t = W/P

    now W = 4,186 x (100 – 20)
    = 334.88 kilojoules

    .. so from that we get 334,880 / 2400 which is 139.5 seconds – which is 2.33 minutes.

    This result fits our everyday experience.

    The metric system is an absolutely marvellous system and I recommend its use to everyone.

    Here’s a bit more about it from Wikipedia ..

    Since the 1960s the International System of Units (“Système International d’Unités” in French, hence “SI”) has been the internationally recognised standard metric system. Metric units are widely used around the world for personal, commercial and scientific purposes.

  5. Gerry Mander

    December 18, 2009 at 3:28 pm

    There is another aspect which nobody has factored in when looking at the data for climate change, and this can also be relevant to forests as well, as trees suspire water into the atmosphere at a very great rate.

    Water has the highest latent heat of any substance, taking 1 calorie to heat 1 cc of water 1 degree celsius.

    Because of global warming more water is entering the atmosphere through eveporation and there is more cooling potential attached to this water. It also absorbs carbon dioxide as well and produces carnonic acid, which then falls as acid rain, acidifying the rivers and oceans.

    This higher water content is a regulator and can distort the actual figures of the warming attributed to carbon dioxide content and can cause the greater extremes that we see in the climatic range of temperatures, causing the sceptics to say that this warming is not happening.

    What IS happening is that the drier areas are getting considerably hotter, and the temperate areas much wetter and have the effect of being cooled further during periods of rain, thus distorting somewhat the mean temperature. However, the rain itself is warmer and more acidic, which no-one seems to have studied.

    These two effects of greater heating and cooling side-by-side have the propensity to create more violent weather patterns, which we currently see sweeping the world.

    The increased acidity coupled with higher ocean temperatures is having a dramatic effect on the life in the oceans. Corrals and shelled molluscs are increasingly disappearing, and with much of the higher levels of life. It does not take much imagination to see that this can spell an absolute disaster for ALL marine life, and we face the prospects of having dead oceans. To many, this will mean starvation and a greater burden on land based food. The populatioon is set to double in the next fifty years … if it can!

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