Untapped potential of American land to combat climate change

New study shows better stewardship of land use in the US could cost-effectively cut the equivalent of over a fifth of US greenhouse gas emissions – equivalent to the weight of 55,000 Statues of Liberty.

In the wake of the landmark United Nations 1.5 degrees report, a new study shows that efforts to improve land use at a US state level could deliver major results to mitigate climate change. The study shows how the United States’ forests, grasslands and coastal wetlands could play a much bigger role in reducing global warming than previously thought. It is the most comprehensive national assessment to date of how greenhouse gas emissions can be reduced and stored through a series of “natural climate solutions.” Natural climate solutions (or NCS) are proven ways of storing and reducing carbon emissions in the world’s forests, grasslands and wetlands.

The peer-reviewed study, published in the journal Science Advances and led by The Nature Conservancy alongside 21 institutional partners found by conserving, restoring and improving the management of natural and agricultural lands, it’s possible to increase carbon storage and avoid greenhouse gas emissions in the US to the tune of 1.3 billion tonnes a year. This is the equivalent to removing more than a fifth (21%) of the carbon pollution in the US and represents more than a tenth of the global potential of natural climate solutions. The study is the first in the US to include the potential of coastal wetlands and grasslands, alongside the more established areas of forests and agriculture.

Joe Fargione, Director of Science for The Nature Conservancy, was the study’s lead author:
“One of America’s greatest assets is its land. Through changes in management, along with protecting and restoring natural lands, we demonstrated that we could reduce carbon pollution, filter water, enhance fish and wildlife habitat, and have better soil health to grow our food — all at the same time.  Nature offers us a simple, cost-effective way to fight climate change, which promises benefits now and for future generations.”

Lynn Scarlett, Chief External Affairs Officer for The Nature Conservancy said,
“As the world focuses on pathways to reduce our global carbon emissions as discussed in the Paris Accord, investment in new technologies is crucial. However, we can’t overlook the solutions that are right in front of us and available now. Governments can prioritise land use strategies that both reduce emissions and absorb more greenhouse gases. This can be done through planning and zoning decisions, and by aligning fiscal or economic incentives with land use policies that benefit the climate. This study provides good news that making investments in nature will make a big difference, while offering the potential for new revenue to farmers, ranchers, foresters, and coastal communities at the same time.”

Of the 21 natural solutions analysed, increased reforestation (the planting of trees) emerged as the largest means available to achieve greater carbon storage at a landscape level, equivalent to eliminating the emissions of 65 million passenger cars annually.  Other high-performing forest solutions include allowing longer periods between timber harvest to increase carbon storage; increasing controlled burns and strategic thinning in forests to reduce the risk of ‘megafire’; and avoided loss of forests from urban sprawl.

The study identified a maximum of 156 million acres with potential for reforestation, 123 million acres where forest harvest rotations could be extended; and 82 million additional acres of forests in the US that would benefit from fire risk reduction treatments on federally managed forests. In addition, almost a million acres of forest are currently being converted to non-forest habitat a year, largely due to suburban and exurban expansion, which could be addressed through better land use planning. The study also finds that urban reforestation can add important carbon storage benefits.

Grasslands – being lost at the rate of over one million acres per year – are another under-appreciated carbon storage opportunity. When these natural landscapes are converted to cropland, about 28% of the carbon in the top meter of soil is released into the atmosphere. The study suggests 13 million acres of marginal cropland could potentially be re-enrolled in conservation programmes and restored to grassland, providing habitat and restoring carbon to the soil.

The study builds on the TNC-led science published last year which found that natural climate solutions could deliver global reductions of as much as 23.7 billion tons of CO2 equivalent per year, approximately 30% more than previous, less comprehensive estimates. This is a third of the reduction required by 2030 if we are to avoid the consequences of catastrophic climate change.

Natural climate solutions provide value for money, create jobs and improve local livelihoods, and help meet the U.N. Sustainable Development Goals. They provide additional benefits such as reduced flooding, improved air and water quality; soil health; biodiversity; and increased adaptation and resilience to natural disasters associated with a changing climate.

As US states and the US federal government increasingly evaluate rules and markets for greenhouse gas emissions, these low-cost reductions from natural solutions should be a fundamental part of the discussion.

Editors Notes

To visualize the amazing potential of what we call ‘Natural Climate Solution Pathways’ please visit the mapper built using 11 different approaches, all broken down at the state level. The table ranks US states by mitigation potential, and also that state’s contribution to the US National level, including the land area available for implementation. At a more detailed level, click on an individual state to see the ranked contribution of each pathway. This information is indicative of the US states’ potential for NCS, we encourage more detailed analysis at the state level for policy and planning purposes.

About The Nature Conservancy: The Nature Conservancy is a global conservation organization dedicated to conserving the lands and waters on which all life depends. Guided by science, we create innovative, on-the-ground solutions to our world’s toughest challenges so that nature and people can thrive together. We are tackling climate change, conserving lands, waters and oceans at an unprecedented scale, providing food and water sustainably and helping make cities more sustainable. Working in 72 countries, we use a collaborative approach that engages local communities, governments, the private sector, and other partners. To learn more, visit www.nature.org or follow @nature_press on Twitter.