If you’re looking to make a positive impact on the climate through carbon credits, you’re faced with a wide range of options, from nature-based to engineered. This post breaks down two of the most popular options for carbon credits – forest carbon and direct air capture.

What is a Carbon Credit

A carbon credit represents a tonne of CO₂ removed, or avoided from entering, the atmosphere. Individuals and organizations often use carbon credits to make a positive impact in order to offset the negative impact of their greenhouse gas emissions made somewhere else. Carbon credits are just one piece of ensuring society mitigates the worst impact of climate change. In order to meet society’s 2030 and 2050 climate goals established in The Paris Agreement, we need to both directly reduce emissions from all aspects of society and invest in carbon credits to offset emissions that cannot be eliminated.

What is a Forest Carbon Credit

A forest carbon credit incentivizes additional carbon storage in forests. According to the U.S. Forest Service, America’s forests sequester 866 million tons of carbon a year, around 16% of the typical US annual emissions. Forests represent the largest potential for carbon storage on our planet, make up the vast majority of carbon storage to date, and are an immediately deployable method for storing more carbon. Nature has already been doing this on its own long before us, and investing in forest carbon credits provides the opportunity to make nature-positive contributions to climate mitigation.

How Forest Carbon Credits Work

Trees remove carbon from the atmosphere through photosynthesis, storing it in their trunks and limbs (trees are about 50 percent carbon). Forest carbon credits increase the carbon storage happening in forests and are available using one of three main approaches:

1. Avoided deforestation compensates landowners for avoiding converting their land to a different land use such as agriculture
2. Improved forest management incentivizes particular forest practices to increase the carbon stored in forests, such as when a timber harvest is delayed
3. Afforestation and reforestation rewards the planting of new forests, or spurs the restoration of previously existing forests, such as reclaiming old mining land back to forest

Because forests have been studied for a long time, there is almost 100 years of public inventory data in the United States on the carbon content in different forest types and ages. Paired with the advent of satellite imagery technology, it is now possible to effectively estimate the carbon content in different types of forests, on a tree-by-tree basis. This type of technology-forward forest science helps reduce the overall cost of carbon project development and impact measurement. This helps enable larger participation in forest carbon projects such as those by NCX because cost savings can be passed to landowners while increasing the integrity of credits for buyers.

The Positives and Negatives of Forest Carbon

Forest carbon projects come with a number of co-benefits that make them an appealing choice to many carbon credit buyers. By avoiding deforestation or restoring forests, you can have biodiversity benefits for wildlife and outdoor recreational benefits for local residents. Forest owners are often families or individuals and participation in carbon projects provides the owner a revenue stream beyond timber harvest, and contributes to their local economy. When carbon projects are accessible to both small and large landowners, it means economic benefits can flow directly to forest dependent communities, often in rural areas, who need it most. If a carbon credit buyer sources their credits in and around their local community, it means they are reducing their carbon footprint while investing in their neighbors and natural surroundings.

Forest carbon credits have also endured their share of scrutiny. As the longest existing types of carbon credits, they’ve had more time to be investigated and analyzed. Forest carbon is naturally temporary as individual trees grow, mature and then die. When trees and wood decompose, that carbon will eventually make its way back into the atmosphere. As carbon makes its way through these systems, carbon credits offer a way to increase the time carbon is stored in forests through working with landowners. Although, even temporary storage can have a significant impact on the atmosphere and models show that this temporary storage can have a critical impact on mitigating the worst outcomes of climate change.

What is a Direct Air Capture (DAC) Carbon Credit

Direct air capture is an emerging technology that focuses on capturing CO₂ directly from the ambient air and locking it away in some form of long-term storage.

How Does Direct Air Capture Work

There are several innovative approaches to the carbon capture and storage process. Once carbon is drawn in from the air, it can be filtered and stored using different methods, including:

1. Using large fans to push carbon dioxide through a sticky filter, concentrate the CO₂ and mix it with water, and then inject that mixture underground to be stored. 
2. Mixing the CO₂ with water and injecting that CO₂ underground where it mineralizes with basalt rock, turning to stone. 
3. Captured CO₂ can be turned into new long term storage products such as concretes and plastics

As of September 2022 there were 18 small scale direct air capture plants operating worldwide. If all of these planned projects were to go ahead, DAC deployment could reach around 5.5 Mt CO₂ per year by 2030; this is more than 700 times today’s DAC capture rate, but less than 10% of the level of deployment needed to get on track with the Net Zero Scenario. 

The Positives and Negatives of Direct Air Capture

Direct air capture is one of the few options for “highly permanent” carbon removal. Meaning, once the CO₂ is removed from the air, it is likely to stay sequestered for 1,000 years or more. In the world of carbon offsets a carbon credit’s permanence, or durability is an important factor. These plants can also employ a range of skill sets in local communities.

The simplicity that comes with sucking CO₂ out of the air and storing it makes direct air capture an appealing concept, but as a newer technology it has yet to be tested at any significant scale. As a currently nascent approach, a DAC carbon credit is among the most expensive on the market. DAC also uses energy and materials to construct and run the plants, and without decades of testing under its belt, the actual permanence has not been confirmed. Despite being out of reach for most carbon buyers today, with continued investment in R&D to lower costs and increase efficiency, direct air capture has potential to be an important component of society’s decarbonization strategy. 

Whatever your carbon offset choice, every option has pros and cons:

Virtually all current carbon removal today comes from conventional management of land, primarily via afforestation and reforestation. 

But, the reality is no matter what carbon credit you choose, if it is truly removing CO₂ from the atmosphere above and beyond what would have otherwise happened, you’re doing good for the planet. Reaching society’s climate goals will require investing in forest carbon credits, direct air capture carbon credits, and more.

To learn more about how NCX is working with landowners to create forest carbon credits, see how this restored property outside of Pittsburgh became part of the climate solution.