Nature Loss Threatens America’s Best Defense Against Climate Change

The climate crisis is no longer looming—it is here, in the form of stronger and more frequent hurricanes, destructive and unpredictable megafires, and damaging floods. With it has come a growing awareness among the American public that it’s time for swift action. Since assuming office, President Joe Biden has pushed the United States back into a climate leadership role, setting a targeted emissions reduction goal of 50 percent to 52 percent below 2005 levels by 2030. Meeting this goal will require action in every sector of the economy, every year through 2030. The crisis is urgent, and the pace at which societywide progress must be made is demanding.

Underpinning this whole-economy approach to tackling the climate crisis is nature—forests, grasslands, wetlands, and more—which currently sequesters 10 percent to 15 percent of U.S. emissions each year, according to the U.S. Environmental Protection Agency (EPA). But the climate and conservation community has begun to question how reliable this figure is. According to a new analysis conducted by the Center for American Progress and Conservation Science Partners, nature’s sequestration capacity is shrinking at a time when it’s needed most. The United States is losing natural area at an alarming rate of one football field every 30 seconds.¹ As a result, the potential for America’s natural areas to collectively serve as a sink for carbon emissions is diminishing. In fact, CAP’s recent research shows that due to natural area loss alone, the United States is emitting the equivalent of 15 percent of nature’s sequestration potential every year—a whopping 140 million metric tons of carbon dioxide equivalent (MMT CO₂e).² Further, wildfires have been burning with more severity and across larger areas than at any time in modern history, adding carbon to the atmosphere and further decreasing the sequestration potential of forests and other lands. These sobering facts should sound alarm bells for policymakers. If nothing is done, America will lose a tremendous tool in the fight against the climate crisis: nature.

However, there is a simple solution. Dedicated conservation action such as President Biden’s sweeping vision for conserving and restoring 30 percent of U.S. lands, waters, and ocean by 2030—known as 30×30 and laid out in the administration’s America the Beautiful initiative—would not only preserve the current rate of carbon sequestration in natural areas but also improve it. CAP’s analysis finds that compared with the status quo, achieving the 30×30 goal will expand nature’s capacity as a carbon sink, pulling, on net, an additional 215 MMT CO₂e out of the atmosphere and storing it away each year.³ That’s as much as taking 47 million cars off the road.⁴

What’s more, CAP’s analysis shows that achieving 30×30 would secure up to 126,900 MMT CO₂e in America’s natural carbon sink—an enormous amount of carbon equal to more than three times annual global emissions. In addition, 30×30 will stabilize the potential for natural areas in the United States to provide long-term climate benefits.⁵

This issue brief lays out the findings from CAP’s new research and demonstrates that it’s time for a paradigm shift in thinking about the interconnected climate and nature crises. Conservation doesn’t just help America weather climate change; it is a foundational piece of the climate solution. Yet current carbon accounting methods underestimate how much the United States and the world stand to lose and overlook nature’s full contribution to a stable climate. Any serious proposal to tackle the climate crisis must include ambitious conservation and restoration action; working toward the 30×30 goal would do just that.

Achieving 30×30 would move the United States closer to its 2030 climate goal

Making investments in conservation and restoration in order to conserve 30 percent of the United States’ land area is an essential strategy for reducing emissions to 50 percent below 2005 levels by 2030. Specifically, slowing the rate of natural area loss, returning forests to the private lands where they once stood, and restoring ecologically appropriate fire patterns in at-risk forests have significant climate benefits. All told, achieving the 30×30 goal could increase America’s natural carbon sink, which currently sequesters from 750 MMT CO₂e to 800 MMT CO₂e annually, by 215 MMT CO₂e annually in 2030 when compared with the status quo; over the next 10 years, it could mean sequestering an additional 2,260 MMT CO₂e cumulatively by 2030.⁷

Figure 1

Slowing nature loss

If past trends in nature loss continue, the United States can expect to lose an additional 15.3 million acres of nature over the next 10 years, contributing an extra 1,400 MMT CO₂e to the atmosphere over the next decade. This is the equivalent of continuously running another 30 coal-fired power plants through 2030.⁸ For context, the EPA estimated that natural areas sequestered around 790 MMT CO₂e in 2019.⁹

Slowing the destruction of natural areas—which is primarily driven by suburban sprawl, oil and gas wells, and pipelines—by increasing land conservation would avoid up to 60 percent of those emissions.¹⁰ On an annual basis, achieving a national 30 percent conservation goal would reduce emissions from nature loss by 50 MMT CO₂e to 85 MMT CO₂e in the year 2030.¹¹ This is equivalent to taking more than 18 million gasoline-powered cars off the road or converting 10 million homes to clean energy.¹²

Replanting historical forests on private lands

In addition to new conservation, restoration of degraded lands will be key to achieving 30×30. Many ecosystems have been affected by decades of human activities such as logging, mining, and wildfire suppression, which not only harm wildlife habitat and water quality but also inhibit the ability of lands to sequester and store carbon.

Studies have shown that there are more than 132 million acres of historically forested land in the United States where new forests could be planted.¹³ Ecologically appropriate reforestation has the potential to store significant amounts of carbon while also protecting water sources, connecting landscapes, and creating new wildlife habitat. The vast majority of the land appropriate for reforestation—nearly 115 million acres—is privately owned.¹⁴ CAP’s analysis finds that reforesting just 30 percent of these privately held acres over the next decade could store an additional 100 million metric tons of carbon annually in the year 2030¹⁵—the equivalent of annual emissions for nearly 22 million passenger vehicles.¹⁶

Protecting these forests—through tools such as conservation easements—will only make them more valuable for the climate as they mature in the decades after 2030.¹⁷ CAP’s analysis finds that from now to 2050, this same historically forested land could cumulatively store up to 2,400 MMT CO₂e in total¹⁸—more than one-third of total annual U.S. greenhouse gas emissions in 2019.

Fire restoration in Western forests

CAP’s analysis finds that restoring historic fire patterns on up to 15 million acres of high-priority Western forests can reduce emissions by up to 30 million metric tons of CO₂e in the year 2030.¹⁹

Wildfire is a natural part of most ecosystems in the United States,²⁰ and by international convention, it is left out of accounting for anthropogenic emissions. However, a century of fire suppression policy and intensive logging—combined with drier and warmer weather driven by climate change—has set the stage for larger, more intense, and more frequent wildfires, which send entire stands of trees, and the carbon they store, up in literal smoke. This leads to an imbalance where forests burn much faster than they regrow—and often fail to regenerate—increasing greenhouse gas concentrations in the atmosphere and shrinking nature’s potential to store carbon. The U.S. Forest Service has identified around 50 million acres of the National Forest System where historic fire patterns no longer occur.²¹ If left untreated, CAP estimates these lands could emit 1,300 MMT CO₂e due to catastrophic wildfires over the next decade, an amount of carbon that would take decades to be recaptured by gradual regrowth on the burned land.²² Worse still, as climate change causes ecosystem types to change, some burned lands will not recapture the full amount of carbon released.

Where it is ecologically appropriate, restoration through the reintroduction of less intense fires that leave many trees standing²³—and reflect historic fire patterns, including those practiced for millennia by Indigenous people in those areas²⁴—would leave forests and soils in better health and better able to store carbon over the long term.

Because fire risk is not evenly distributed, this work can be prioritized effectively. CAP’s analysis finds that ecosystem restoration activities on 5 million to 15 million acres, representing just 10 percent to 30 percent of these at-risk lands, could prevent up to 900 MMT CO₂e emissions over the next decade; this is nearly 70 percent of the expected net carbon loss from fire.²⁵ This will keep critical stores of carbon locked in healthy, thriving ecosystems even as the climate continues to warm.

Figure 2

Achieving 30×30 would protect an enormous amount of carbon that accounting methods overlook

While achieving 30×30 would generate 215 MMT CO₂e in carbon savings in the year 2030, conserving 30 percent of U.S. lands and waters for future generations would also secure a future for carbon already stored in plants and soil—and allow ecosystems to continue to sequester carbon. All told, up to 126,900 MMT CO₂e could be protected in conserved areas.²⁶ Even when discounting emissions from wildfire on conserved lands, that’s more than three times annual global emissions.²⁷ What’s more, due to data limitations on the climate impacts of wildfire, these estimates of annual natural area loss apply only to the continental United States and are therefore a significant underestimate. Data for Alaska show that carbon storage numbers would be greater still for the entire United States. For example, conservation of the Tongass National Forest—which stores 8 percent of all U.S. forest carbon in its old-growth trees—the Arctic National Wildlife Refuge, and the Western Arctic would have significant positive climate effects.

This is important because, although nature has long been considered a core piece of carbon accounting methods, these methods tend to focus on annual emissions and sequestration in isolation, overlooking nature’s full potential to store carbon and the long-term consequences of losing and degrading nature.

Policy conversations on climate change revolve around greenhouse gas emissions by sector, often depicted in an area chart.²⁸ What happens to natural areas—technically referred to as the land use, land-use change, and forestry (LULUCF) sector—and the carbon they store each year forms the foundation of area charts. Unlike every other sector, the net annual emissions from natural areas are negative, as carbon is pulled out of the air and stored in nature.

The sequestration by U.S. natural areas that is depicted in annual emissions inventories—the area charts—has been relatively constant since the 1990s, creating an assumption that nature will stay intact, siphoning off and storing away 10 percent to 15 percent of the country’s annual carbon emissions. This capacity to sequester carbon is shrinking, however, with EPA estimates dropping from 900 MMT CO₂e in 1990 to 789 MMT CO₂e in 2019. Yet to many audiences, the sector already accounts for so much sequestration overall that the factors affecting this decline are easy to overlook.²⁹

On the ground, though, the United States is losing a football field of natural area every 30 seconds to development, year after year.³⁰ Clearing forests, draining wetlands, and plowing grasslands releases vast amounts of carbon that would otherwise remain stored by nature. While these ecosystems can sequester carbon if they are allowed to recover, an acre of land has less sequestration potential when converted from a forest to a subdivision, or when grassland is plowed under to plant crops.

These losses add up, but they are overlooked because the benefits of nature don’t fit neatly into a climate area chart. Trees aren’t cars; therefore, conservation cannot be thought about in terms of a single year or even several years of avoided emissions and sequestration.

Tracking emissions sources and sinks on an annual basis can make sense for climate policy experts, who need common metrics to set targets for emissions reductions. But the bigger picture—how much carbon is stored in nature—cannot be ignored in seeking to limit overall atmospheric concentrations of greenhouse gases. In fact, when thinking about the contributions of nature to emissions reductions, taking the long view and considering the incredible storage potential of these lands over time is more valuable and more accurate than reducing it to annual snapshots.

It’s true that in the absence of formal protections, not all of these lands and their carbon storage potential would be immediately lost. But the historical pattern of degradation and loss of natural areas without explicit protections is undeniable. It’s clear that strong conservation policies are the best defense against the loss of nature and biodiversity, which means the carbon benefits that conservation affords must not be overlooked.

Figure 3

Conclusion

Recommendations for how America can conserve and restore 30 percent of its lands, waters, and ocean by 2030 are outside the scope of this issue brief, but CAP and others have written³¹ extensively³² on the conservation³³ and restoration³⁴ policies that could get the nation there. What climate and conservation advocates and policymakers should take away from CAP’s new research is that the United States is quietly and rapidly losing its best defense against climate change. As nature is developed or burned in catastrophic fires, critical capacity to store vast amounts of carbon is lost. Conservation and restoration can and must be part of the climate solution; otherwise, lands will be a growing part of the problem. The nation can no longer afford to think of natural areas as its carbon bank without ambitious action to protect and increase the climate-saving power of these places. President Biden’s ambitious America the Beautiful initiative can turn U.S. lands from a ticking climate bomb—instigated by the loss of nature and increasing wildfires—into a reliable and growing carbon sink.

The authors would like to thank Trevor Higgins, Shannon Baker-Branstetter, Sally Hardin, Mark Haggerty, Elise Gout, Bianca Majumder, Mikyla Reta, Carl Chancellor, Corinne Muller, Meghan Miller, Keenan Alexander, and Conservation Science Partners for their contributions to this brief.

Appendix

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