CO2 Sequestration

Below, you’ll find links to articles and other resources with information on trees’ ability to sequester CO2, and thereby mitigate climate change.

Our belief in trees’ power to mitigate climate change is also supported by research conducted by Project Drawdown, one of the world’s most respected climate change focused organizations. The Drawdown team has created an extensive list of the most promising strategies for slowing and reversing climate change, ranked in terms of efficacy. Out of the top twenty solutions on this list, five directly involve trees.

Notes:

Excerpts:

“The restoration of forested land at a global scale could help capture atmospheric carbon and mitigate climate change. Bastin et al. used direct measurements of forest cover to generate a model of forest restoration potential across the globe (see the Perspective by Chazdon and Brancalion). Their spatially explicit maps show how much additional tree cover could exist outside of existing forests and agricultural and urban land. Ecosystems could support an additional 0.9 billion hectares of continuous forest. This would represent a greater than 25% increase in forested area, including more than 200 gigatonnes of additional carbon at maturity. Such a change has the potential to store an equivalent of 25% of the current atmospheric carbon pool.”

Published in 2018 by The World Resources Institute

Excerpts:

“There is untapped potential to increase carbon removal in America’s forests and farms. However, although marginal costs of implementation are generally below US$50/metric ton of CO2 (tCO2), deploying these approaches at large scale will require addressing a set of needs related to scientific uncertainty, measurement, and monitoring; mechanisms to drive landowner adoption at large scale; and public funding.”

“If these needs can be addressed, the potential scale of deployment in the United States is likely on the order of hundreds of millions of metric tons of CO2 (MtCO2) per year.”

“Several studies have estimated the marginal cost of carbon removal in forests to be generally less than $50/tCO2e (Fargione et al. In Press; Murray et al. 2005; Richards
and Stokes 2004; Lubowski et al. 2006).”

“In all, the (most recent study on U.S forests’ carbon sequestration potential) found 580 MtCO2 per year of potential carbon removal in forests in the United States at marginal costs of less than $100/tCO2—with most potential available at significantly lower costs. Significant emissions reduction potential was also found for land-sector measures like avoided forest conversion.”

Notes:

Excerpts:

“We assess the aboveground C sequestration potential of four major plantation crops – cocoa (Theobroma cacao), oil palm (Elaeis guineensis), rubber (Hevea brasiliensis), and orange (Citrus sinesis) – cultivated in the tropics.”

“Measurements were conducted in Ghana and allometric equations were applied to estimate biomass. The largest C potential was found in the rubber plantations (214 tC/ha). Cocoa (65 tC/ha) and orange (76 tC/ha) plantations have a much lower C content, and oil palm (45 tC/ha) has the lowest C potential, assuming that the yield is not used as biofuel.”

“There is considerable C sequestration potential in plantations if they are established on land with modest C content such as degraded forest or agricultural land, and not on land with old-growth forest. We also show that simple C assessment methods can give reliable results, which makes it easier for developing countries to partake in REDD + or other payment schemes.”

Notes:

Excerpts:

“According to the researchers, forests collectively absorbed around 15.6 billion metric tons of carbon dioxide from Earth’s atmosphere each year between 2001 and 2019, while deforestation, fires, and other disturbances released an average of 8.1 billion metric tons of carbon dioxide per year. Forests around the world are estimated to absorb about 7.6 billion metric tons, acting as a net carbon sink of roughly 1.5 times the annual emissions from the entire United States.”

“…the study shows that 27% of the world’s net forest carbon sinks are found within protected areas, such as national parks.”

Notes:

The article discusses reforestation efforts such as the Bonn challenge, and does a compare and contrast between agroforestry, plantations, and natural regrowth, in terms of each strategy’s ability to mitigate global warming.

“Over the past 15 years or so, China has planted millions of trees and created millions of hectares of new forest cover, much of it in areas with marginal agricultural potential. “China’s land use policy increased forest cover in southern China between 10 and 20 percent, turning these areas into intense managed forests,” (Saatchi) said. “As a result, they created close to a carbon sink (an area that stores carbon) in their forests, almost doubling their carbon uptake. The effort has offset 20 percent of China’s annual fossil fuel emissions, and since 2012 that percentage has increased to 33 percent. So that’s a success story.””

Excerpts:

“The amount of C in soil represents a substantial portion of the carbon found in terrestrial ecosystems of the planet. Total C in terrestrial ecosystems is approximately 3170 gigatons (GT; 1 GT = 1 petagram = 1 billion metric tons). Of this amount, nearly 80% (2500 GT) is found in soil (Lal 2008). Soil carbon can be either organic (1550 GT) or inorganic carbon (950 GT). The latter consists of elemental carbon and carbonate materials such as calcite, dolomite, and gypsum (Lal 2004). The amount of carbon found in living plants and animals is comparatively small relative to that found in soil (560 GT). The soil carbon pool is approximately 3.1 times larger than the atmospheric pool of 800 GT (Oelkers & Cole 2008). Only the ocean has a larger carbon pool, at about 38,400 GT of C, mostly in inorganic forms (Houghton 2007).”

“Big agriculture companies including Bayer AG , Nutrien Ltd. and Cargill Inc. are jockeying with startups to encourage crop producers to adopt climate-friendly practices and develop farming-driven carbon markets. Those efforts would let retailers, food makers and other companies offset their greenhouse gas emissions by paying farmers for their fields’ capacity to withdraw carbon dioxide from the atmosphere and trap it in the soil.”

“The Environmental Protection Agency has estimated that the agriculture sector accounts for 10% of U.S. greenhouse gas emissions.”

“President-elect Joe Biden’s administration also plans to pursue the concept. Mr. Biden said this month that under his administration, the U.S. Department of Agriculture will direct federal conservation payments to farmers who use their fields to capture more carbon.”

“In early November, Mr. Garrett posed in one of his corn fields with an oversize check for $75,000, proceeds from selling 5,000 carbon credits that his farm generated through a program being developed by the agricultural startups Nori LLC and Locus Agricultural Solutions.”