Can Trees Make Much Difference in the Fight Against Climate Change?
Understanding carbon footprints, credits & sequestration.
I love nature. It’s been part of who I am since I was a small child growing up on a homestead in Alaska. I worry about climate change and loss of habitat. I recycle, compost, and eat a plant-based diet.
Here in Austin, there is a local organization, Tree Folks, dedicated to planting trees in Central Texas. A friend was telling me that part of their operating budget comes from selling carbon credits, and we realized that neither of us understood how that works.
Thinking about it, I realized I didn’t understand precisely how carbon sequestration and carbon footprint worked either. The more I thought about, the more questions I had.
How much value was there in the Trillion Tree Project? How many trees would we have to plant to offset part of the greenhouse gas (GHG) humans produce each year? How big is my carbon footprint each year?
Industrial activities and deforestation have raised atmospheric carbon dioxide levels from 280 parts per million to over 400 parts per million in the last 150 years. The problem is that we are producing more CO2 than can be recycled by the environment.
Thinking about climate change feels overwhelming; it’s easy to feel helpless.
If we don’t understand it, we can’t help fix it.
All living things are made, nearly entirely, of four basic elements — hydrogen, oxygen, nitrogen, and carbon. These elements comprise 99 percent of our body, and most of a tree’s roots, trunks, branches, and leaves.
We, humans, get most of our carbon construction materials from food. Trees absorb carbon from carbon dioxide in the air during the process of respiration. The bark, trunk, and branches store carbon and the leaves exhale oxygen.
A mature tree can consume forty-eight pounds of carbon dioxide per year and releases enough oxygen for a human to breathe for two years.
Carbon credit = one ton of carbon dioxide.
According to the Carbon Fund, a carbon credit is an instrument that represents ownership of one metric tonne of carbon dioxide equivalent (using co2 as a unit to measure different greenhouse gases) that can be traded, sold, or retired.
Governments and international organizations set a limit or cap on the amount of GHG that can be released. Businesses are budgeted a specific amount of carbon they can release annually.
If my company produces more than my allotted amount, my business can buy unused credit credits from another company or purchase carbon offsets.
One carbon offset equals a single metric ton of carbon dioxide that has been removed from the atmosphere. Examples of carbon offsetting include planting trees, installing solar power, and wind energy farms.
If you plant one maple tree today, assuming it grows well, in twenty-five years it will have stored about 25 tons of carbon.
Before you get too excited—consider that the average person in the United States, Australia, and Canada produces between 15 and 17 tons of carbon every year. However, the global average in 2017 was 4.8 tons for each individual.
Image credit Our World in Data
Carbon production is closely tied to the income level of a country’s population. Our carbon footprint includes not just our direct uses of fuel and energy, but the carbon that’s produced in all the food and consumer goods we use.
For comparison, in only 2.3 days the average American or Australian produces as much co2 as the average resident of Nigeria or Mali does in an entire year. In order to avoid a devastating 2℃ rise in global temperatures, the average global carbon footprint per year must be under 2 tons by 2050.
Yikes! How can we lower our carbon footprint?
First, it’s helpful to look at our present consumption. Carbon footprint calculators are broad but they do help us get an idea of how lifestyle choices affect consumption. After comparing several, I found the Footprint Network site to be the most useful.
Author’s screenshot from Footprint Network
Even though I live a frugal, mindful life, I barely squeaked into the ‘okay’ category. One long trip, and I’d be over the mark! If I think of carbon output as a budget, I have to decide what to allocate it on.
Living alone in an apartment built with a lot of brick and cement, produced more greenhouse gases than building with wood. I can’t change that right now, but I can eat a plant-based diet that creates less CO2 than one heavy in beef.
I can choose to pay a little more for electricity to support my utility company’s effort to move toward renewable power generation. All of us can consider each purchase that we make — the less we buy, the less we contribute to increased global warming.
If you are leaving a big footprint, consider buying some credits. Each carbon credit is calculated to offset one ton of CO2. Get information on the process and purchase here at City Forest Credits.
So back to the trees and carbon offsets.
Forests absorb carbon dioxide and store carbon to reduce global climate change while we transition off fossil fuels. At the same time, trees purify the air, provide wildlife habitat, and shade to lower energy consumption.
This is where carbon sequestration provides an essential piece of the solution. Plants, including long-lived species like trees, absorb CO2 and turn it into wood and leaves.
As long as the tree is alive or milled into lumber or biochar, it stores the carbon molecule in the inert product. When the tree burns or decays, the carbon is released into the atmosphere.
So planting forests of living trees, holds or sequesters, a sizeable amount of carbon.
Experts estimate terrestrial plants remove about twenty-five percent of the CO2 generated each year. Another twenty-five percent is used by the aquatic plants in the ocean.
Data now shows that if the right species of trees are planted in the correct soil types around the planet, the enlarged forests could capture 205 gigatons of carbon dioxide in the next 40 to 100 years. That’s two-thirds of all the CO2 humans have produced since the industrial revolution.
“Forest restoration is by far our most powerful planetary solution today,” says Tom Crowther, a professor of global ecosystem ecology at the Swiss Federal Institute of Technology in Zurich, and an author of a study published in Science.
There is enough room on the planet to add 12 trillion more trees than are currently growing.
I am fortunate to live in Austin, Texas, a city that pays serious attention to maintaining and expanding green space and urban forests.
Trees in Austin currently store about 1.9 million tons of carbon (7.0 million tons of carbon dioxide [CO2]); such storage is valued at $242.0 million. In addition, these trees remove about 92,000 tons of carbon per year (336,000 tons CO2/year) ($11.6 million per year) and about 1,253 tons of air pollution per year ($2.8 million per year). Abstract; Austin’s Urban Forest Report, 2014.
So yes, trees can make a substantial contribution to reducing climate change and I am better educated about the process
The more we all know, the better equipped we’ll be to make thoughtful decisions affecting our carbon footprints. Humanity can’t afford to procrastinate.
For more information, check out Ecosystem Marketplace.