Addressing climate change
is ambitious, necessary, & achievable.

We all know that forests are a natural climate solution. But not all forests are the same.

How can climate-smart forestry maximize our forests’ ability to mitigate the effects of climate change?

Let’s take a look at the data1.

This square represents
10 million metric tons (MMT) of CO2e.2

CO2e emitted by

2,225,000
U.S. passenger vehicles
1,945,000
American homes’ electricity use
2.7
Coal-fired power plants

per year.

What is CO2e?3

In a single year, the U.S. emits roughly
6,340 MMT of CO2e.4

Some perspective:

*This figure is gross, yes, but not the icky kind.
Why are there so many different numbers for this floating around?6

The good news:

Growing trees sequester
1,082 MMT of that CO2e.7

Just so we’re clear…

Sequestration is the active process of removing CO2 from the atmosphere through photosynthesis. Growing trees capture CO2, convert it into carbon and store it as solid wood. Harvested trees made into wood products continue to store the carbon they captured as growing trees.

Sequestration and storage are different.8 Keep reading to see how.

Ok, but…
It can’t be as simple as just looking at the amount of carbon trees suck from the atmosphere each year.

What about emissions?
What about wildfires?
What about x, y, z?

You’re right, but you need to read on…

  1. Let’s Look at the Data

    Welcome to radical transparency, aka THE CITATIONS. Before you X this out, be aware that this is NOT your average list of citations. Take it from us, citations can be mind-numbing and confusing. Is this source credible? Where in the 400+ page document did you pull this number? What does this dataset include, what does this NOT include? We’ve done our best to explain everything plainly, right here in this panel. Just click on the green text in the main scroll, and we’ll tell you where we got the data, why we chose it, and we’ll even answer the questions we had about the data… because we expect you’ll be asking those questions too.

    This website uses the best publicly available data. Citations housed in this panel show sources throughout, but most of the data are sourced from the EPA’s Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2021, the U.S. Forest Service Forest Inventory and Analysis (FIA) program, or the U.S. Forest Service’s 2020 RPA Assessment. It’s important to note that this page uses national data for all 50 states.

    Accuracy, Transparency and Continual Improvement

    This data visualization is intended to help users better understand how forests and climate intersect using the best, publicly available data sets, most of which are provided by the U.S. government. Many serious climate conversations are underway in the public and private sector. Our working theory is that a common understanding of the relationships between forests and climate, the terminology, and most importantly, the data, will encourage productive dialogue and lead to good policy.

    This page embraces what we call “radical transparency.” We have made our best effort to include precise citations and explain wonky scientific jargon in language that average humans can understand. That said, we’re humans too. We know that there are many ways to visualize concepts, interpret data, and simplify language. We hope our work spurs critical thinking, questions and dialogue.

    If you have a question, a correction, a better source, or a good idea for what else we could do here, we want to hear from you. Email us at info@nafoalliance.org.

    Similar to every website, we have our own disclaimers. We want to make sure that you understand exactly what our Forest Carbon Data Visualization is – and what it’s not. The Forest Carbon Data Visualization is not intended to:

    …provide complete carbon accounting for the US;

    …discuss biomass carbon neutrality;

    …quantify emissions from burning biomass in manufacturing facilities;

    …claim carbon credits or offsets in a market sense;

    …replicate or explain details from the EPA Greenhouse Gas (GHG) Inventory; or

    …rigidly adhere to accounting structures developed by the United Nations Framework Convention on Climate Change (UNFCCC) for the sole purpose of international reporting of emissions.

    Our Forest Carbon Data Visualization is simply intended to show you the potential of trees, especially trees in private, working forests, to remove carbon from the atmosphere through the process of sequestration and keep that carbon out of the atmosphere by storing it in trees. In accounting terms, these numbers are “gross.” This is not the same as the “net” carbon sequestration estimates for forests you will find in the EPA GHG Inventory Report (we’ll explain the whole net vs. gross thing later), so please don’t try to compare the two.

    Then, so you can get an idea of the magnitude of the carbon sequestration and storage potential of private working forests, we compared them to things like the total US fossil fuel combustion emissions, automobile emissions, and wildfire emissions. These comparisons are purely for the purposes of, well, comparison, because the numbers come from entirely different datasets, so please don’t assume any kind of direct equivalency or one-to-one exchange. Keep reading the citations as you go along for more in-depth explanations.

    Whenever possible, this section will show the exact source for data presented. Sometimes, the data is in a program we can’t link directly to, like the FIA data, or the data needs some analysis. This explainer from the team at NCASI, Inc. describes that analysis in plain language and includes supporting tables.

    This data visualization was developed by the National Alliance of Forest Owners. Data analysis was performed by the National Council for Air and Stream Improvement, Inc. (NCASI).

    EPA GHG Inventory

    The Inventory of U.S. Greenhouse Gas Emissions and Sinks, which was published in 2020, is part of an ongoing series of reports developed by the U.S. government to meet annual U.S. commitments under the United Nations Framework Convention on Climate Change (UNFCCC).

    The U.S. Environmental Protection Agency (EPA), in cooperation with other U.S. government agencies, prepares the Inventory of U.S. Greenhouse Gas Emissions and Sinks (Inventory). A wide range of agencies, organizations, and individuals is involved in supplying data, planning methodological approaches and improvements, reviewing, or preparing portions of the Inventory, including federal and state government authorities, research and academic institutions, industry associations, and private consultants.

    Within EPA, the Office of Atmospheric Programs (OAP) is the lead office responsible for the emissions calculations provided in the Inventory, as well as the completion of the National Inventory Report and the Common Reporting Format (CRF) tables. EPA’s Office of Transportation and Air Quality (OTAQ) is also involved in calculating emissions for the Inventory. The U.S. Department of State serves as the U.S. focal point to the UNFCCC, and EPA’s OAP serves as the National Inventory Focal Point for this report, including responding to technical questions and comments on the U.S. Inventory. EPA staff coordinate the annual methodological choice, activity data collection, emission calculations, quality assurance/quality control processes, and improvement planning at the individual source and sink category level. EPA, the inventory coordinator, compiles the entire Inventory into the proper reporting format for submission to the UNFCCC, and is responsible for the synthesis of information and consistency of cross-cutting issues in the Inventory.

    Several other government agencies contribute to the collection and analysis of the underlying activity data used in the Inventory calculations, in addition to the calculation of estimates integrated in the report. These include the U.S. Department of Agriculture’s (USDA) Forest Service (USFS) and Agricultural Research Service, the National Oceanic and Atmospheric Administration (NOAA), the Federal Aviation Administration (FAA), and the Department of Defense (DOD). Formal relationships exist between EPA and other U.S. agencies that provide official data for use in the Inventory. For example, the U.S. Department of Energy (DOE) Energy Information Administration (EIA) provides national fuel consumption data, and the DOD provides military and bunker fuel consumption. Informal relationships also exist with other U.S. agencies to provide activity data for use in EPA’s emission calculations. These include: the USDA, NOAA, the U.S. Geological Survey (USGS), the Federal Highway Administration (FHA), the Department of Transportation (DOT), the Bureau of Transportation Statistics (BTS), the Department of Commerce (DOC), and the Federal Aviation Administration (FAA). Academic and research centers also provide activity data and calculations to EPA, as well as individual companies participating in voluntary outreach efforts with EPA. Finally, EPA as the National Inventory Focal Point, in coordination with the U.S. Department of State (DOS), officially submits the Inventory to the UNFCCC each April.

    More information can be found here.

    FIA

    USDA’s Forest Inventory and Analysis (FIA) is widely regarded as the best strategic forest inventory in the world. FIA collects, analyzes, reports, and distributes data about the nation’s forests: how much forest exists, who owns it, what condition it’s in, where it’s located, and how it’s changed.

    RPA

    This publication provides forest resource statistics contributing to the USFS 2020 Resources Planning Act (RPA) Assessment to provide current information on the nation’s forests. Resource tables present estimates of forest area, volume, mortality, growth, removals, and timber-product output in various ways within the context of changes since 1953.

    U.S. Department of Agriculture, Forest Service. 2023. Future of America’s Forest and Rangelands: Forest Service 2020 Resources Planning Act Assessment.

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  2. 10 MMT of CO2e Comparisons

    These comparisons are provided to put 10 million metric tons (MMT) into real-world perspective. They’re taken directly from the EPA’s Greenhouse Gas Equivalencies Calculator.

    If you’re looking at this number of total U.S. vehicles registered and trying to back into the 1,068 MMT of CO2e figure for total passenger vehicle emissions, you might notice that they don’t line up perfectly. That’s because the EPA and the Department of Transportation have different terms for “passenger vehicles” We use the source terminology, but it leads to some misalignments. We’re trying to talk about cars on the road, or automobiles. This is an instance where, because of accounting and nomenclature nuances, everyone is right… but everyone is saying slightly different things.

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  3. What is CO2e?

    CO2e, or Carbon Dioxide Equivalent, is a common unit for comparing various greenhouse gases. Individual greenhouse gases (GHG) have different global warming potentials. Converting these potentials to CO2e, using conversion formulas, provides a single, common reference to express global warming potential. CO2e is the amount of CO2 that would create the same amount of warming as the reference GHG. CO2e is now the most common way to express “emissions”, which helps when setting policy like emissions reduction targets.

    This helpful link explains carbon terms and units.

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  4. Total U.S. Emissions

    This is the total gross United States greenhouse gas (GHG) emissions from 2018… from the 2020 RPA assessment. This datapoint is from the EPA GHG Inventory (Table 2-1)

    Give it to me straight. What does this include, what does it not include? Total gross emissions mostly includes fossil fuel combustion – electric power generation and tail pipes – but it also includes emissions from things like landfills and enteric fermentation in domestic livestock (that’s how scientists say “cow burps”). It does NOT include biogenic emissions included in Land Use, Land Use Change and Forestry (LULUCF), which is a separate emissions category.

    What about biogenic carbon emissions? Total gross emissions does not include biogenic carbon emissions (emissions from combustion of biomass, like wood and biofuels and “natural” emissions like those from fire or the decomposition of trees or other vegetation) because those are accounted for in the LULUCF emissions category. Including them in the total gross GHG emissions would result in double counting when the net emissions are determined.

    Why? It’s nearly impossible to accurately report biogenic carbon emissions. Think about countries where many homes rely on wood stoves and open fires for cooking and heating. Or dead plants decaying in a wetland. Plus, unlike fossil fuel, the biogenic carbon cycle is actually a two-way street, meaning that carbon can also be “removed” from the atmosphere while plants grow. There really isn’t any way to measure those emissions alone, and since there is so much transfer both ways between the atmosphere and land in any given year, there needed to be a different approach to accounting for them.

    Let’s zoom in on wood, which comes from forests (the “F” in LULUCF). If we measure or estimate the amount of carbon in forests every year, we can calculate how much the carbon stocks change from year to year. This change is called the carbon flux. The carbon flux includes gains in carbon from, for example, tree growth, and losses in carbon from, for example, wildfire, wood being removed from the forest and burned for energy, or natural decomposition. The GHG Inventory reports carbon flux for forest land, cropland, grassland, wetland, and settlements (places where people live), all under the heading of LULUCF.

    The good news is that by combining the gross U.S. GHG emissions with the total U.S. carbon flux from LULUCF, we can get an estimate of the total amount of U.S. GHGs actually released to the atmosphere (net emissions) without having to measure all the biogenic carbon emissions. The bad news is that by using this accounting approach, multiple types of biogenic carbon emissions and carbon sinks are combined in a single number and you can’t separate one from the other. That’s why we’ve tried to look at this a little bit differently, which you will see as you scroll.

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  5. U.S. Passenger Vehicle Emissions

    We use passenger vehicles as a reference simply because, well, everyone does! Cars have been the standard mechanism for perspective on climate data for years, so we’re putting this data in the context most people are used to. If you have a car, this is where the emissions from your tailpipe are counted.

    In 2021 there were more than 102 million passenger vehicles registered in the U.S.

    When folks think of “passenger vehicles” they think of cars. This figure includes emissions from cars, yes, as well as the gasoline and diesel emissions from light-duty trucks. This figure comes from the EPA GHG Inventory (Table 3-13). More information on vehicles can be found on the Bureau of Transportation Statistics site, here.

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  6. Why are there so many different numbers floating around?

    These days, you can’t pick up a new climate report without tripping over a new top-line sequestration number. The complexity of this topic provides plenty of room to interpret, analyze, and report the data in lots of different ways. The reality is that we’re all humans, attempting to measure a complex, active, and continuous natural process, so it can get a bit messy.

    The important thing to know is that the most commonly used numbers focus on different things for different purposes, but they all fit together. There are three numbers for “total sequestration” that are most commonly used:

    This page uses 1,082.3 MMT of CO2e

    This figure is gross, total U.S. forest carbon sequestration – meaning only forestland in all 50 states – other land uses, like agriculture, are omitted. This is what we calculated using FIA data. See our Methodology Explainer for greater detail.

    The White House and EPA use 800 MMT of CO2e.

    This number is the 2019 net LULUCF sequestration, rounded off to 800 seemingly because it makes the math easier. It is for all 50 states and for all land use types.

    The Forest Service frequently updates their figure to use the best available science and data. For 2021, they showed 785 MMT of C02e, but they will likely revise it in the future, so don’t be alarmed if it changes. Remember: these figures are net “CONUS”/ lower 48 states only, and include forest land, harvested wood products, woodlands, and urban trees in settlements.

    Key questions to ask to understand top-line sequestration figures:

    Is this a GROSS sequestration or NET sequestration figure?

    The figures represented on this page are GROSS, meaning they’re the simplest, most direct answer to the question “How much carbon do trees suck out of the air each year?” For this data visualization, the use of gross figures is intentional to show a complete picture of the sequestration work our forests are doing. It is akin to a business reporting total revenue, before accounting for expenses, debts, costs, etc.

    The White House/EPA and Forest Service numbers most often quoted are NET, meaning they account for all the additions and subtractions of carbon transferring into or out of the atmosphere and just report the net impact. This is necessary when setting emissions reduction goals, because it gives a clear view of what needs to be done.

    Is this a CONUS/Lower 48 or Total U.S. figure?

    Despite how lovely Alaska and Hawaii are, it’s always best to ask whether or not a figure includes them. The inconsistencies across data, agencies, and studies will surprise you. This page uses U.S. numbers, meaning all 50 states. The Forest Service numbers are “CONUS”, which is military/ scientist speak for continental United States, meaning they include only the lower 48 states.

    Why is Alaska so different?

    One-sixth of the nation’s forest is located in Alaska; it has more forest area than the 24 least forested states combined. Much of Alaska’s forest is so remote that it is accessible only by helicopter or foot, which makes measuring inventory plots extremely hard to do and expensive. Most of this forest is “taiga”, forests at the edge of tundra, where black spruce trees may only grow 1/50th to 1/20th of an inch in diameter per year, and few ever grow taller than 40 feet.

    Consequently, Alaska has been a low priority for measurement by FIA. While inventory has been conducted in the highly productive timberland in Southeast Alaska, only in the past decade has much effort been expended to inventory timberland in interior Alaska. That work has relied on extensive use of remote sensing to cover vast areas at reasonable cost.

    On this page, we used rates of growth on timberland in Alaska reported by the RPA assessment to estimate sequestration rates, and we used FIA data to estimate carbon stocks. These estimates cover only about 10% of Alaska’s forest, and because of the differences between the productive timberland in Southeast Alaska and the extensive taiga forests of the interior, we cannot extrapolate these estimates to all of Alaska.

    Is this a forest specific or a total land use figure?

    This page sticks to forests, and specifically what you might call “traditional” forests or “woods”. This page does not include urban trees or forests – sorry, Central Park.

    The White House/EPA number includes the total land base which includes cropland, wetlands, urban trees, etc.

    Another thing you might be wondering is, if we know gross forest carbon sequestration and the net flux in forest carbon storage, can’t we just subtract net from gross and get the total annual emissions from forests?

    The short answer is “No.” Remember when we were talking about how carbon flux is calculated for LULUCF? The emissions that are captured in that calculation include not just biogenic carbon emissions from forests but also industrial emissions from energy production and transportation that include biomass as part of the fuel mix. It’s impossible, at least for now, to accurately and completely separate the biomass portion of these emissions. Consequently, we can’t calculate an accurate biogenic emissions total under LULUCF. This is not to be confused with biomass combustion emissions reported in Chapter 03: Sequestration, Storage, & Emissions here.

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  7. Growing trees sequester 1,082 MMT of CO2e

    This figure is calculated through an analysis of the RPA and FIA data. The analysis was done by the National Council of Air and Stream Improvement (NCASI). You can read about the data analysis methodology in full here.

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  8. Sequestration vs. Storage

    A lot of people mix up sequestration and storage, and even smart people use them interchangeably when they’re actually quite different – kind of like when moms call every gaming console a “Nintendo.” Don’t do that.

    Sequestration is a natural, active process by which carbon is captured. A sequestration rate is an accounting for how much carbon was captured from the atmosphere over a specific period of time. Storage refers to how much carbon is stored at a specific point in time, like a snapshot. It’s always best to ask for clarification if forest carbon data is presented to you and sequestration/storage is unclear.

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