The Truth About Trees
Many people understand how trees help the Earth cycle and store carbon dioxide. And that’s great. But that fact alone misses the full picture of the limits on the role trees can play in helping solve the climate challenge and the important role of technology.
Trees and the Carbon Cycle
From the standpoint of biology and physics, carbon is life. According to NASA, there are about 65,500 billion metric tons of carbon on Earth comprising rocks, soil, plants, people, animals and practically all living things. Carbon naturally cycles between the oceans, the land and the atmosphere through processes such as respiration during the decay of plant matter, the burning of fossil fuels and, critically, photosynthesis.
Atmospheric carbon is present as carbon dioxide (CO2), though of course not all of Earth’s carbon exists in this form. Trees play an essential role in helping the planet manage this CO2, making the entire carbon cycle work. Through the process of photosynthesis, trees extract atmospheric CO2 and store carbon in their roots, branches and stems. When they die and rot, or are burned in a forest fire, this carbon is then released back into the atmosphere. In such a way, the planet has managed its own CO2 levels for millenia.
Man-Made CO2 Imbalance
Beginning with the Industrial Revolution, we’ve been steadily increasing the amount of anthropogenic carbon dioxide (or commonly referred to as “man-made” carbon dioxide) that’s released into the atmosphere. So much so that now the natural carbon cycle balance has been overwhelmed. Symptoms of this imbalance include Climate Change, the effects of which are impacting us all. And many would have some people believe that simply planting trees is the answer.
Indeed, the world could use more trees—for many reasons. In terms of carbon storage, a single tree over the course of 25 years could sequester about 400 pounds of carbon dioxide. That’s about the amount of CO2 a single passenger car would emit driving from San Francisco to San Diego. So it’s true that planting more trees is a must for keeping CO2 in check worldwide.
But the more nuanced, and accurate, understanding is that from where we are today trees are going to need our help to get us back on course. A family of four would have to plant six acres of trees to offset its lifetime CO2 production. The problem is that there’s just not enough land to make the math work. If we planted 1.7 billion acres of trees it would eliminate 3 billion tons of atmospheric carbon annually; this would be great but also take up as much land as almost the entire Continental United States. And here we start to see the issue. Three billion tons is only about 10 percent of what humans emit around the world every year (an estimated 37 billion tons). Carbon stored in trees is not permanently and securely removed from the air: drought, fire or deliberate harvesting can quickly re-release much of the stored carbon dioxide back into the air.
Branching Out through Technology
What many experts, engineers and economists have learned over the years is that there will be no silver bullet for addressing the problem of atmospheric CO2. And this includes trees. But there are some promising technologies, models and approaches that can make a huge impact on the aggregate—and give trees a much-needed assist.
Occidental’s partnership with Carbon Engineering is creating practical applications for Direct Air Capture (DAC) technology that has the potential to capture the equivalent of more than 40 million trees’ worth of CO2 directly from the atmosphere annually. We’re developing new models such as our Clean Campus, which is helping manufacturers of all kinds transition to carbon-friendly operation. And the Permian Basin CO2 storage infrastructure has the capacity to store about 150 billion tons of CO2 safely and permanently underground; that’s the equivalent of 300 trillion trees.
So it’s helpful to support efforts to plant trees at scale, not only for the purpose of carbon management but also because of their vital role in ecosystems, human health, food supply, wildlife support, community development and the economy. But let’s not place them in the impossible position of being a panacea for addressing atmospheric carbon. Let’s do our part to help them restore the balance.< Back