Forests and Atmospheric Carbon Dioxide

Today is BC Day, a statutory holiday in the Province of British Columbia. And here on the Pacific coast, in British Columbia's capital city of Victoria, as we celebrate the existence of this colonial settlement, smoke from forest fires burning hundreds of kilometers away in the interior of the Province has turned the sun red and the air toxic.

Such fires are not unusual. Since 2008, fires have consumed 44,000 square kilometres of forest in British Columbia, equal to about one tenth the area of the Province's commercial forest. And there is nothing special about the forests of British Columbia. Wildfires consume millions of hectares of forest across Canada almost every year.

Coldstream, BC, July 9, 2021: Source: Williams Lake Tribune

And fires are not the only cause of forest destruction. Each year, Canadians log around a million hectares of forest, of which a significant proportion may be converted to ranch land or remaindered as NSR (not sufficiently restocked) forest land in the continuation of a process of deforestation begun in 1608 when Samuel Champlain, with the blessing of King Henri Quatre of France, arrived on the shore of the Gulf of St. Lawrence to implant a branch of the French nation in North America.

The process of forest destruction is not uniquely Canadian: it occurs worldwide, across Eurasia, in Amazonia, and throughout Africa, with losses totaling around 100,000 square kilometres each year.

Does that matter?

Certainly it has huge consequences. Forests account for around 80% of the world's biomass, most of the world's photosynthetic capacity, and provide home to the great majority of the World's plant and animal species.

But here I want to consider just one consequence. How does deforestation affect atmospheric carbon dioxide concentration, with whatever consequences that may have for climate.

The atmosphere weights about 10 tons per square meter. Of that mass, carbon dioxide accounts for 596 parts per million (or 416 parts per million by volume). Therefore, over each square meter of Earth's surface, the atmosphere contains approximately six kilograms of carbon dioxide.

The carbon content of mature forests range between one hundred and one thousand tons per hectare, which is equivalent to between 160 to 1,600 kilograms of carbon dioxide per square meter.

From that, it follows that the destruction of one unit area of forest and the complete transformation of the carbon that it contains into atmospheric carbon dioxide, has an effect equal to that of doubling the atmospheric carbon dioxide concentration over an area between 26 and 266 times greater than the area deforested.

Given the current rate of global deforestation, which is around 100,000 square kilometers a year, or an  area 8% larger than the nation of Hungary, and assuming an average forest carbon content of 100 tons, it follows that the yearly effect of deforestation on atmospheric carbon dioxide concentration corresponds to the effect of  doubling the atmospheric carbon dioxide concentration over an area of 6.6 million square kilometres, an area more than 70 times the size of Hungary, and equal to 1.2% of the Earth's total land and marine surface.

Thus, if the process of global deforestation were to continue at the present rate for the next 100 years, the world would still retain three quarters of its present forest area, but all other things being equal, atmospheric carbon dioxide concentration would have doubled.

Related:
CanSpeccy: Rising Atmospheric Carbon Dioxide Concentration, Part I: Carbon Dioxide Is Not a Greenhouse Gas

Rising Atmospheric Carbon Dioxide Concentration, Part I: Carbon Dioxide Is Not a Greenhouse Gas

In 1750, atmospheric carbon dioxide concentration was around 275 parts per million (ppm) by volume or just over 400 ppm by mass. By 1850, the concentration had risen by about 10 ppm by volume, or 3%, as the result of the increasing use of coal in Europe, and particularly in Britain. By 1950, when industrialization and the associated use of fossil fuels had spread around the globe, the atmospheric carbon dioxide concentration reached 320 ppm by volume, an increase of about 12% in a century. Today, atmospheric carbon dioxide concentration is around 390 ppm by volume, an increase over the pre-industrial value of 41%. On present trends, atmospheric carbon dioxide concentration will reach at least twice the pre-industrial concentration before the end of this century.

Image source: The Encyclopedia of Earth

As everyone knows, carbon dioxide is a greenhouse gas — except that it isn't. There is no such thing as a greenhouse gas, and here's why. When the sun warms the ground, heat is transmitted to the air in contact with the ground, and that warmed air is then carried aloft by convection, often to a height of thousands of meters (that is why it is possible, by locating the up-draughts, for a sailplane pilot to keep his craft aloft for many hours on a sunny day). A greenhouse, allows solar radiation to heat the ground, and hence the air in the greenhouse, but it prevents the warm air from being convected away, hence, on a sunny day, the air inside a greenhouse is always warmer than the air outside. So-called greenhouse gases do not work this way.

But while there is no such thing as a greenhouse gas, atmospheric carbon dioxide does affect the Earth's temperature by absorbing infra-red radiation, or heat. In particular, it absorbs some, a very small amount, of the heat that the Earth radiates to space. When global temperature is constant, the Earth radiates to outer space an amount of energy exactly equal to the amount it receives from the sun. If the atmospheric carbon dioxide concentration is raised, a tiny additional fraction of the heat emitted by the Earth in the direction of the sky is absorbed by the newly added carbon dioxide, thus warming the planet. As the Earth warms, it emits an increasing amount of heat to space until a new balance between incoming and outgoing radiation is reached.

In terms of climate, therefore, the significance of carbon dioxide is that it is a heat absorbing gas. But it is not a very powerful heat absorbing gas. Water vapor, for example, absorbs heat radiation about ten times as strongly as carbon dioxide and occurs in the atmosphere at a concentration about ten times that of carbon dioxide. Methane, or natural gas, is an even more powerful heat absorbant than carbon dioxide (one hundred times more powerful), and it leaks to the atmosphere in massive quantities from gas pipelines, oil drilling operations, and many natural sources.

So, yes, rising atmospheric carbon dioxide concentrations will, all other things being equal, cause some climate warming. But all other things will never be equal. And many of the other things that are not equal are subject to human influence. Particles of black carbon or soot, for example, injected into the atmosphere by diesel powered vehicles, oil-burning ships, and forest fires, absorb heat and may be as significant as carbon dioxide in accounting for any human-caused climate change. But sulfur emitted to the atmosphere by the combustion of coal, for example, gives rise to white sulfate particles, which reflect sunlight and thus cool the planet. Sulfate particles also seed cloud formation, and clouds have a huge impact on global temperature in many and complex ways, some tending to raise global temperature, some having the opposite effect. There's also the impact of human activity on the surface features of the planet. Deforestation, for example, has a long-term cooling effect, because trees reflect less solar energy back to space than do bare ground or agricultural crops, but in the short run, deforestation may have a warming effect by causing the transfer of carbon from the biosphere to the atmosphere.

So, no, the science of climate change is not settled, and when Al Gore says it is he only demonstrates that, scientifically, he is a moron. Either that, or he sees the global warming scare a means to psych the semi-educated American and European populations to regard themselves as some kind of disease on the planet, with a moral obligation to commit racial suicide by having no children. That is what the elite desire and what they promote. What, after all, in this age of automation, is the use of the consuming masses: best be rid of them.

Related: 

CanSpeccy: Rising Atmospheric Carbon Dioxide Concentration, Part IV: Reversing the Trend

CanSpeccy: Rising Atmospheric Carbon Dioxide Concentration, Part III: Induced Stupidity and the Decline of the West

CanSpeccy: Rising Atmospheric Carbon Dioxide Concentration, Part II: Ecosystem Disruption