“Blue skies smilin’ at me, Nothin’ but blue skies do I see.”
~ Irving Berlin, Blue Skies
Take a deep breath, then exhale. You have just accomplished what every tree, indeed, all vegetation, accomplishes continuously. But unlike humans, trees absorb carbon dioxide and emit oxygen. That — trees replenishing our oxygen — is what makes the planet livable for most of the life on earth.
When it’s cold, you can see your breath. (Sure, sometimes after a particularly spicy meal or a bad night on the town you can see your breath anyway, but that’s different.) What you see is the water vapor you are exhaling as it condenses when it encounters the cold air. Like us, trees also exhale moisture. Researchers Michael Wolosin and Nancy Harris noted to Fred Pearce, “The water that a single tree transpires daily has a cooling effect equivalent to two domestic air conditioners for a day.”
Pearce goes on to say, “Every tree in the forest is a fountain, sucking water out of the ground through its roots and releasing water vapor into the atmosphere through pores in its foliage. In their billions, they create giant rivers of water in the air — rivers that form clouds and create rainfall hundreds or even thousands of miles away.”
He quotes Dominick Spracklen of Leeds University in England, “Healthy forests release a range of volatile organic compounds that ‘have an overall cooling effect on our climate,’ mostly by blocking incoming solar energy … removing forests eliminates this cooling effect and adds to warming.”
Eillie Anzilotti notes a study by The Nature Conservancy, “Trees are sustainability power tools: They clean and cool the air, regulate temperatures, counteract the urban ‘heat island’ effect, and support water quality and manage flow. Yes, they look pretty, but they also deliver measurable mental and physical health benefits to concrete-fatigued city dwellers … urban trees remove enough particulate matter from the air to create up to $60 million worth of reductions in healthcare needs.”
So, it seems, trees are at least partially responsible for not only clean water but clean air, improved health and reducing global warming. Melissa Breyer explains that the Japanese use the term “forest bathing” to describe time spent in forests that provides health benefits, “much of the benefit comes from breathing phytoncides like α-pinene and limonene, which are antimicrobial volatile organic compounds emitted from trees.” Trees reduce noise and cool the surface. The effects are not just physical, but provide stress reduction and improve overall mental health.
The old theory that civilization increased precipitation was espoused by Charles Dana Wilber, “By this wonderful provision, which is only man’s mastery over nature, the clouds are dispensing copious rains … [the plow] is the instrument which separates civilization from savagery; and converts a desert into a farm or garden…. To be more concise, Rain follows the plow.”
We now know that trees and forests are likely one of our best weapons against global warming, but are also needed to maintain regional precipitation. However, our forests are currently being eliminated across the globe in the name of progress. Pearce on the ‘giant rivers of water in the air’ says, “But as we shave the planet of trees, we risk drying up these aerial rivers and the lands that depend on them for rain. A growing body of research suggests that this hitherto neglected impact of deforestation could in many continental interiors dwarf the impacts of global climate change. It could dry up the Nile, hobble the Asian monsoon, and desiccate fields from Argentina to the Midwestern United States.” This effect would worsen the climate shifts due to global warming and render existing agricultural areas less able to meet the world’s future food demands.
In contrast to our so-called ‘modern’ approach to agriculture, a recent study determined that the Amazon rain forest was actually developed by the indigenous peoples thousands of years ago. The University of Exeter study notes, “Early Amazon farmers used the land intensively and expanded the types of crops grown, without continuously clearing new areas of the forest for farming when soil nutrients became depleted.” They planted trees with edible fruits and nuts and farmed the surface under the canopy. They added manure and other materials to bolster the soil productivity, and controlled the flooding.
Today, we are cutting down forests across the globe. The Amazon rainforests that were developed to be sustainable thousands of years ago can also reduce global warming and provide regional precipitation, clean water, clean air and improved health.
Forests are being destroyed in order to unsustainably raise beef for Big Macs. Doesn’t that seem a little short-sighted to you?
To paraphrase comedian Bill Engvall, “There’s your sign!”
Eillie Anzilotti, Cities Should Think About Trees as Public Health Infrastructure, October 2, 2017, Fast Company
Melissa Breyer, Vast New Study Confirms Significant Health Benefits of Nature, July 9, 2018, Treehugger Daily News
Fred Pearce, Rivers in the Sky: How Deforestation is Affecting Global Water Cycles, July 24, 2018, Yale Environment 360
University of Exeter, Ancient Farmers Transformed Amazon and Left an Enduring Legacy on the Rainforest, July 23, 2018