Carbon sequestration by planting forests

How can planting Forests help us tackle climate change?

Global warming and climate change are direct results of human activities. Due to these activities, the concentration of greenhouse gasses (GHG) in the atmosphere has increased considerably over the last ~150 years (well, really since humans have been around, but who’s counting?). The longest lasting of these GHGs, carbon dioxide, has risen to over 400 parts per million. This number has been below 300ppm since humans beings have existed. (For more details, my post here has an expanded explanation.)

The project of tackling climate change is exceedingly complex and contains many unknown unknowns. If anything is certain, it is that in order to save Earth from worsening condition due to climate change, we need to make some big changes. In regards to carbon sequestration, these can be broken into two categories. (Adaptation is a third and vitally important response to climate change, read more about it here).

First, we need to curb excess carbon emissions. This involves (but is in no way limited to) cutting down on how much we drive and fly, modifying our eating and shopping habits, and changing agricultural, industrial, and manufacturing processes.

Second, we need better carbon sequestration. This is the process of removing the excess carbon dioxide humans have put into the atmosphere. I wish I could tell you that we have machines and technology to do this, but we don’t. At least nothing that is scalable (though the tech does exist).

There are many known ways in which the Earth naturally performs carbon sequestration. These include various processes such as weathering, oceans, mangrove swamps, and peat bogs.

However, the most effective and well known mechanism for capturing carbon already in the air is… Forests!

climate change global forests
Polynesian rain forest. PHOTO: I, Sémhur, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2436548

Most plants pull carbon dioxide from the air and use sunlight to convert it into nutrients (remember photosynthesis?). Forests help store carbon in several ways (from US Forest Service):

  • aboveground in stems, branches, and foliage
  • long-lived products, such as wood, continue to store captured carbon after the tree is cut down, providing longer term storage (for example, wood used for a chair or a toy continues to store carbon until the wood burns or decays)
  • soil in the form of roots, rotting debris, and soil organisms (long, and super interesting article about soil sequestration)
  • inorganic carbon and rock provide very long term carbon storage
So, we can just plant a bunch of trees?

Not exactly…

In July, Science magazine published an article titled “Adding 1 billion hectares of forest could help check global warming“. This article discussed findings which claimed that the current global climate could support an additional 1 billion hectares (that’s the size of the U.S.!) of forests. This additional amount of forests could have the potential to store around 200 gigatons of carbon, roughly 2/3 of the carbon humans have added to the atmosphere since the 1800s.

This maps shows where new forests could potentially be planted. (Credit: J. BASTIN, ET. AL., SCIENCE, 2019)

There are some caveats that we need to consider:

  • Discover Magazine responded to the report, pointing out that carbon in the atmosphere from human emissions is closer to 600 gigatons, not 300 gigatons as the report claimed. So the impact of the new forests would not be 2/3, but rather 1/3, of the excess atmospheric carbon. (Obviously the correct ratio is important, but 200 gigatons is still impressive in my book!) 
  • It is the entire forest ecosystem, not just trees specifically, which is so effective at storing carbon. (That doesn’t mean we shouldn’t plant trees, just that we need to make sure we are planting native trees sustainably along with appropriate organisms.)
  • The Wikipedia article on Reforestation notes that tropical regions are best suited for forestation for several reasons (notably longer growing seasons and more rainfall). This highlights the complicated intersections of global climate change, where industrialized nations, which have done the majority of damage, are now telling countries that are still trying to grow their economies that they need to stop. (Read more here on the inequities and ethics of tackling climate change.)
Here’s the scary part.

A truly terrifying twist: if we don’t cease the current deforestation going on right now, then planting new forests will be practically pointless. The potential benefits of planting huge swathes of new forest can’t effectively counteract the carbon poured into the atmosphere if we can’t protect our existing forests. The act of cutting down old growth forest releases the stored carbon. Additionally, the related activities of deforestation (fires, transport, and so on) are all massive emitters of GHGs.

Summer 2019 was the hottest on record. Hotter temperatures lead to more fires. The US and Europe experienced unprecedented heatwaves in the US and Europe. Massive fires in the Arctic, across Alaska, Canada and Russia are burning boreal forests and peat, two vitally important carbon sinks (or sponges) which have been storing carbon for millenia.

AT THE SAME TIME, deforestation of the Brazilian Amazon rainforest appears to be accelerating. Increases in deforested lands leads to increases in fires set by ranchers and farmers to clear out land for new fields and crops.

From a Newsweek article, Brazil’s President (aka “Captain Chainsaw”, now referring to himself as “Nero, setting the Amazon aflame”) “has moved to weaken government agencies that are responsible for protecting the rainforest, as well as regulations covering indigenous lands and nature reserves.” This threatens not just forests but the people and traditional cultures living there.

From the Intercept’s Rainforest on Fire, the Amazon “exhales a fifth of Earth’s oxygen, stores centuries of carbon, and deflects and consumes an unknown but significant amount of solar heat. Twenty percent of the world’s fresh water cycles through its rivers, plants, soils, and air. This moisture fuels and regulates multiple planet-scale systems, including the production of “rivers in the air” by evapotranspiration, a ceaseless churning flux in which the forest breathes its water into great hemispheric conveyer belts that carry it as far as the breadbaskets of Argentina and the American Midwest, where it is released as rain.”

We are at a climatic tipping point.

there is hope

We can look for examples of Hope across the world. There are countries and individuals already working to make a difference and reverse the loss of forest. There are tree planting initiatives going on all over the world. Plus there is some cool tech that may help us in this endeavor.

Hope in the Amazon. In response to the reduced protections for the Amazon, and recent massive fires there, Germany and Norway have suspended aid to be sent to Brazil. France and Ireland are also threatening action. The loss of aid to the Amazon Fund, which promotes rainforest protection, is not exciting. What gives me hope in this story is that there are still governments around the world that are willing to take a tough stance against international activities which threaten to worsen the climate crisis. Additional hope can be found in Equador, where indigenous tribes have won other battles to protect the rainforest there.

Once complete it will be the largest living structure on the planet. (Image from zmescience.com)

Africa’s Great Green Wall. Originally a project to plant trees to stop the spreading of the Sahara, it has evolved into a development planning tool, helping communities thrive and adapt to climate change. “By 2030, the Wall aims to restore 100 million hectares of currently degraded land, sequester 250 million tonnes of carbon and create 10 million jobs in rural areas.” (From greatgreenwall.org.)

The Treepods concept (above) is one of various carbon-capture technologies that act like artificial trees, sucking CO2 from the air through their canopies.
Artificial trees. INFLUX_STUDIO/SHIFTBOSTON

Technology can help, too! Companies like BioCarbon Engineering may help speed up the planting process. They uses drones (aka “sky tractors”) to accelerate reforestation (not just trees, but the accompanying ecosystem as well). Carbon sequestration technologies, such as artificial trees, may help in areas that are not right for forests.

Individuals are also making an impact. Consider Felix Finkbinder. In 2007, at 9 years old, he decided to plant 1 million trees. Three years later, he succeeded. Now his organization, Plant for the Planet, owns its own land in Mexico where it is planting trees, and in 2018 kicked-off the Trillion Tree Campaign. Felix was inspired by Wangari Maathai. Born in Kenya, she developed the Green Belt Movement which used tree planting to improve communities and promote conservation. Since its founding in 1977, the GBM has planted 51 million trees.

take action

The issue is not as simple as planting a tree in your backyard (you can still do that anyway). Factors that need to considered in a global reforestation plan include the types of trees (and accompanying ecosystem), where in the world they are planted, and impacts to human activity (such as urban growth, agriculture). We also need to halt unsustainable deforestation. There are still many ways that we can take action individually.

Get fired up! 
Watch this video, Forest, from Conservation International. Listen to Felix Finkbinder address the UN. Watch the trailer for Taking Root, a documentary about Wangari Maathai. Read Rainforest on fire, a long, troubling, but highly informative article from the Intercept. 
Take steps to protect the Amazon. 
Sign Greenpeace's petition asking Brazil protect the Amazon and the indigenous and traditional communities there. 

From Monga Bay, cattle ranching is attributed to ~70% of deforestation, the rest is mostly from subsistence and commercial agriculture (notably palm oil and soy). 

You don't have to stop eating beef completely, but sourcing it locally would have the same effect. 

The World Wildlife Fund has palm oil guidelines including which foods it is used in (and why), a list of ingredient names to look out for, and how to identify products that use sustainable palm oil. 

Cut down on wood and paper products. When possible, look for the Rainforest Alliance froggy, which tells you the product was sustainably sourced. 
Support organizations involved in tree planting. 

Join Plant for the Planet to Stop Talking and Start Planting!

Get involved with the Green Belt movement planting trees or making donations. 

The Arbor Day Foundation's Time for Trees initiative (Arbor Day Foundation)- by 2022, plant 100m trees, and inspire 5 million planters.
 
Find a local organization like Friends of Northern Arizona Forests, which supports state forest service.

Use ecosia.org as your search engine; they plant a tree for every 45 searches you make!

Purchase carbon offsets, such as carbonfund.org, which are used towards ethical reforestation. 

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