Trees & Climate
Photo by Simple Insomnia
Trees and Human Survival
“Forests precede civilisations and deserts follow them.”
— Chateaubriand, French diplomat, 1768-1848.
Without trees, there would be no life on Earth – at least, not one habitable by humans. It is as simple as that. NO TREES, NO HUMANS. It is worth repeating!
One of the many reasons for this simple life-and-death equation is the highly significant roles that trees play in the Earth’s eco-system, as well as in the many subsidiary ecosystems on which its teeming multitudes of creatures depend. Not least are the contributions of trees in the creation of the Earth’s atmosphere and regulation of its climate. In relation to this:
photo by randihausken
Every year our atmosphere loses around 10 billion cubic metres of oxygen, replacing it with carbon dioxide. Our industries, what may be called our technosphere, consumes about 20 times more oxygen than all living organisms put together. In other words, our supply is being depleted. Knowing this should help us appreciate the vital contributions made by trees. During the course of its life, an average 100 year old tree will have made available 6,600 kilograms of oxygen for living creatures. A single tree such as a mature Beech can produce enough oxygen for 10 people for a year. Cut down a Beech and you condemn 10 people. Cut down a hundred and you condemn a village. Cut down a forest and you are committing genocide; aside from destroying wild-life habitats. Cut down woods and forests and replace them with factories and housing estates, you are doing no service to humankind. You are a blight, not a blessing, on civilization; and the face of this Earth.
Photo by randihausken
Trees Soak Up Carbon Dioxide
During the course of its life, a single average 100 year old tree (see below) will have fixed the amount of carbon dioxide (CO2) contained in 18 million cubic metres of air in the form of about 2,500 kilograms of pure carbon. Soviet experts have calculated that a hectare of well-working forestry annually absorbs about 6.5 tons of carbon dioxide while releasing 3.5 to 5 tons of oxygen. The performance of different species varies of course. One acre of American Sycamore can extract 3 tonnes of carbon from the atmosphere per year. Plantations of Poplars absorb 7 times more carbon dioxide than conifers. “Forests have to be planted on every free acre of land. This is the best ecological antidote against the anthropogenic contamination of the atmosphere,” says Rem Bobrov, Deputy Minister of Forestry of the Russian Federation. “By increasing the acreage of forests and regulating the species composition … we can not only halt but also reverse the process of atmospheric contamination with carbon dioxide and restore oxygen to the atmosphere.”
Trees and Climate Change
This process of absorbing carbon dioxide and releasing oxygen is essential for the well-being of the planet. Because trees and algae perform this task, the Earth is habitable by humans. Without trees, we could not survive. And yet, ignorant of this fact, we have been steadily destroying forests for the past 500 years. Since the beginning of European colonial expansion in 1492, 10 billion acres of forest have been cleared - more than half of the 18.5 billion acres at that time. That leaves 8.5 billion acres remaining, with devastating consequences. As a result, the bulk of planetary oxygen-production has shifted to algae, and greenhouse-gasses are produced more quickly than they can be absorbed.8
For all of human history until around the dawn of the age of fossil fuels, the amount of carbon in the atmosphere was stable at ~275 parts per million (ppm). As Bill McKibben explains, “Parts per million is simply a way of measuring the concentration of different gases, and means the ratio of the number of carbon dioxide molecules to all of the molecules in the atmosphere.”7 275 ppm CO2 is a useful, balanced amount which allows enough greenhouse-gasses to create a warm, livable climate but not so much as to make a dangerously hot one.
Photo by Kevin Dooley
With the discovery of coal, oil, and other fossil fuels, our population and industry have swelled and our carbon-emmisions have soared exponentially. With increased technology and population growth, there has also been deforestation at an increasing rate. As a result, there is now a dangerously high amount of carbon in the atmosphere.
Scientists, climate experts, governments and international organizations have all agreed that 350 ppm is the upper limit for CO2 in the atmosphere. Beyond 350 ppm, the planet can no longer support human life. The problem is, we're already at 390 ppm, and rising by 2 ppm per year. These are not just numbers. They represent the life-support systems of the Earth. On human terms, it is as though we suddenly discovered what the natural human temperature is, and simultaneously realized that we have a life-threateningly high fever. In other words, we're living on borrowed time. The science of Climate Change has been proven beyond doubt, and is happening much faster than experts previously thought.7
An obvious and necessary solution is to look for ways to dramatically cut carbon-emissions to halt the increase of CO2 in the atmosphere. But there are no longer sufficient trees and algae on the planet even to absorb the amount of CO2 added to the atmosphere by plant decomposition and volcanic activity alone! Human activity and industry has created a surge in the amount of carbon in the atmosphere, no doubt. But even if all human-related carbon-emmisions ceased, 4.5 billion tons of carbon would still accumulate each year, because there are not enough trees and plants to absorb the natural planetary carbon emissions.8
As the dangers of Climate Change become increasingly apparent, so too does the need to take dramatic steps to halt and reverse the process before it’s too late. Human-caused carbon emissions and deforestation have been conclusively linked to the Greenhouse Effect, and if we do not act immediately, the extinction of humanity will be the eventual result. Conservation is not enough. We need to take pro-active measures to absorb greenhouse-gasses at an increasing rate. In other words, we need to plant trees, on a colossal scale.
graph by Robert A. Rohde
Thanks to active and widespread education on the science of Climate Change (by 350.org and others), governments and people all over the world are waking up to the importance of this situation and promising to take measures to reduce carbon emissions. But the single most important action that humanity can take in response to climate change at the moment is the reforestation of the 10 billion acres which have been cleared since 1492.
Of course, to accomplish this feat requires action and education on many different levels: economic, ecological, cultural and spiritual – all the ways by which people are motivated. It requires initiatives on an individual, local community, national and international scale. It requires that trees and forests must be regarded as sacred, as they have been by many cultures all over the world. It requires a practical, holistic, and widely available education that recognizes the importance and true nature of trees.
Thankfully, trees deliver countless economic, ecological, cultural and spiritual benefits to people, communities and nations. By reforesting the planet, we can usher in a new golden age of civilization – one with greater health, wealth, and happiness than the one we now know. As Colin Tudge has stated, “In the future of humanity, and of all the world in all its aspects, trees are key players.”
Trees provided the foundation for our current civilization, and they can serve as the cornerstone of a new one – but only if we plant them, on a massive scale, starting now.
There are many individuals whose heroic actions can serve as an inspiration to us all: see Tree Warriors.
In addition to the role of trees and forests in carbon-sequestration and Climate Change, they provide many other climatic and environmental benefits to people:
Trees Play a Significant Role as Atmospheric De-Polluters
Trees play a significant role as atmospheric de-polluters, filtering out dust particles, smoke and fumes. In addition to extracting carbon dioxide, forests act as excellent biological filters.
more about Trees as Atmospheric De-Polluters
Photo by lanier67
Through their roots they draw up moisture from deep levels and discharge it into the atmosphere through their leaves. This is vital in dry weather, not only moistening but cooling the air. How much they are able to discharge depends, naturally, on the combined area of their leaves. A mature beech has up to 7,000,000 leaves with an area of 1.47 evaporative hectares. Standing alone in the open, such a tree can give out around 100 gallons of water a day, about 450 litres.
Afternoon clouds over South America, generated by trees through transpiration.
Photo by NASA. More info
Thus, in the Earth’s water cycles, trees act as pumps. They create zones of moisture above them. If forest cover was more widespread they would be able to distribute water-vapour more evenly through the atmosphere. Further, they attract greater precipitation. The rainfall where trees grow can sometimes be 30 per cent heavier than over woodless areas. They protect watersheds and mountain springs, and generally keep the water table high. Where they do not exist and, therefore, cannot perform their vital functions, lands turn to deserts.
In Many Other Ways, Trees are Climatic Regulators:
Trees affect airflow, temperature and humidity; function as air-conditioners; protect against abnormal extremes of climate; while generally militating against the Greenhouse Effect. In their gentle but persistent way, they are a primary means of defence against Global Warming.
Photo by CaptPiper
The following are calculations by Walter Schauberger, son of the famous visionary forester, Vicktor Schauberger, which he made in the 1970s in relation to a 100 year old tree, a European species of average output. During the course of its life, this 100 year old tree has:
- Produced and fixed the amount of carbon dioxide (CO2) contained in 18 million cubic metres of natural air in the form of about 2500 kilograms of pure carbon (C).
- Photochemically converted 9,100 kilograms of carbon dioxide (CO2) and 3,700 litres of water (H2O).
- Stored up about 23 million kilogram-calories (a calorific value equivalent to 3,500 kilograms of hard pit coal).
- Made available for the respiration of human and beast 6,600 kilograms of molecular oxygen (02).
- Drawn from its roots right up to its crown (against the forces of gravity) and evaporated into the atmosphere at least 2,500 tonnes of water. (Every tree is therefore a water-column and if such a column, which continually supplies and recharges the atmosphere with water, is cut down, then this amount of water is lost.) Thereby fixing a mechanical equivalent of heat equal to the calorific value of 2,500 kilograms of coal.
- Supplied a member of the consumer society with oxygen sufficient for 20 years.
“In view of such achievements, who in the future could value this tree merely for its timber?” Walter asked.
photo by Don Becker
Trees & Natural Disasters
‘Natural’ disasters – and we wonder why!
We have catastrophic flooding around the world. In Indonesia, large parts of its capital Djakarta are metres high in water. Businesses, livelihoods, have been destroyed. Hundreds of thousands have abandoned their homes. In the Philippines, some months previously, there has been a similar story. A state of national emergency was declared. In Bangladesh1, hundreds of thousands are flooded out of their homes annually. In one year, most buildings in its capital Dhaka were under water. On the other side of the globe, mud-slides have swallowed up whole villages, burying their occupants alive. This is in Honduras. It’s a national disaster. It will take decades to recover. Altogether, around the world, tens of billions of dollars worth of damage is done to properties, infrastructures, and vital services. Lives are wrecked. Diseases spread. The human suffering is immeasurable.
We wonder what is going on! ‘Natural disasters’, we call them. That is how our news channels report them, focusing visually and vividly on the effects, while ignoring the causes. What imbecility! Men, women and children are portrayed as victims of nature, when in fact they are victims of man’s mindless exploitations of nature. This is how ignorance is perpetuated, the already uninformed populace never becoming any wiser. Which is exactly what many in authority want!
But what is actually happening?
We have been cutting down trees. The hills above Djakarta have been stripped bare. By whom? By those seeking profits from timber; and, thereafter, from building bungalows for the rich on the cleared land.
When living, trees hold soil in place, softening the impact of the heaviest rains; which is absorbed; then allowed to run off slowly, harmlessly into valleys. Now, unstoppable, it races down mountainsides in devastating torrents.
The foothills of the Himalayas have been stripped bare. Now, inevitably, the plains are flooded, causing monumental destruction and suffering.
These are all man-made disasters.
But when will man take responsibility for them?
photo by CaptPiper
A word here should also be given to the role that trees play in the prevention and mitigation of flooding, as recent weather patterns have shown us that the floods which devastated the west of Ireland this year will continue to be an issue. Reforestation will be an increasingly necessary measure to prevent future disasters in Ireland and elsewhere.
Trees catch rainwater
Leafy tree canopies catch precipitation before it reaches the ground, allowing some of it to gently drip and the rest to evaporate. This lessens the force of storms and reduces runoff and erosion. Research indicates that 100 mature tree crowns intercept about 100,000 gallons of rainfall per year, reducing runoff and providing cleaner water.3
Trees absorb groundwater and protect the soil
Tree roots absorb water from the soil, making the soil drier and able to store more rainwater. They also hold the soil and stream banks in place, reducing the movement of sediment that can clog drains and shrink river channels downstream.
Trees also shade the soil, and create a cooler surface which absorbs rainwater more easily. Additionally, their leaf litter changes the chemical properties of the soil, allowing it to absorb still more soil while giving it more nutrients. This in turn builds a rich layer of humus which can absorb six times as much rainwater as bare ground.
A typical community forest of 10,000 trees will retain approximately 35 million litres of rainwater per year.4
Cost-Effective Flood Control
According to the Irish Timber Growers Association:
“While hugely expensive schemes are often proposed for flood control, we do have the economically viable option of planting more forests as a natural and very effective flood control measure.… Well-planned afforestation and effective management of existing woodlands offer a significant protective function to adjoining waterways and groundwater catchments.… This has positive implications for farmland, the associated rural community and also the wider population in the areas of flood control and wastewater treatment.” 5
However, this benefit is lost if the trees are clear-felled, as is the standard for commercial timber plantations. For the first several years after felling, runoff and erosion are greatly increased watershed receives twice the peak flow, seriously increasing the risk of flooding.6 Stands of living trees, heavily forested areas, and natural wetlands are the most effective form of flood control.
Many of the above extracts are from Gospel of the Living Tree: for Mystics, Lovers, Poets & Warriors by Roderic Knowles, published by (and available online from) Earth Cosmos Press
1. Ó Nualláin, Fiann. 10 good reasons or more to plant a tree. Bord Bía, the Irish Food Board: Link ↑
2. United Nations Environmental Program. Common Facts: Link ↑
3. USDA Forest Service. 2003. “Benefits of Urban Trees. Urban and Community Forestry: Improving Our Quality of Life”. Forestry Report R8-FR 71. [Atlanta, GA:] Southern Region. ↑
4. USDA Forest Service. 2003. “Is All Your Rain Going Down the Drain? Look to Bioretainment-Trees are a Solution”. Davis, CA: Pacific Southwest Research Station, Center for Urban Forest Research. ↑
5. “Timber growers insist planting more trees is natural form of flood control,” by Ray Ryan, Agribusiness Correspondent, Irish Examiner, Friday December 04, 2009 ↑
6. “Fewer trees = more floods?,” Flood of Evidence: Link ↑
7. "350 Science," 350.org: Link ↑
7. "The 10 Billion Acre Story," Ten Billion Acres: Reforesting the World for Human Survival: Link ↑