The Big Picture: What Are Natural Climate Solutions & Why Are They Important?
Natural Climate Solutions are conservation, restoration and improved land management strategies that help remove carbon from the air while also keeping our air and water clean and our soil healthy and productive. These solutions are practical, effective, relatively inexpensive, provide numerous economic benefits to landowners and communities, and can be implemented on a wide variety of different kinds of land, including forests, farms and ranches, grasslands and coastal wetlands. They are an important part of the U.S. plan to reduce greenhouse gas emissions.
Americans overwhelmingly support expanding implementation of these solutions. A poll commissioned by U.S. Nature4Climate reveals that 86% of American voters, including 93% of Democrats, 81% of independents, and 81% of Republicans, supports efforts to expand Natural Climate Solutions practices, supported by laws and public funding approved at the federal, state, and local levels.
The United States Nationally Determined Contribution (NDC) to the Paris Agreement outlines the U.S. plan for reducing greenhouse gas emissions by 50-52% below 2005 levels by the year 2030. The document outlines the U.S. strategy for supporting climate smart agriculture and forestry practices, as well as measures to reduce land sector emissions and increase carbon sequestration and storage in forests, farms, ranches, and wetlands, including peatlands and coastal wetlands.
Natural Climate Solutions can help harness the potential of America’s natural and working lands to mitigate climate change. While we must reduce greenhouse gas emissions, these solutions are an important part of a comprehensive U.S. climate change strategy.
Natural Climate Solutions
The Science: The 2018 study, “Natural Climate Solutions for the United States,” by Fargione et al. serves as a keystone for understanding the carbon mitigation potential of Natural Climate Solutions in the U.S. The paper outlines 21 potential pathways for implementing Natural Climate Solutions, covering forests, agricultural and coastal lands. It analyzes the carbon mitigation potential of each pathway and identifies possible incentives for increasing adoption of Natural Climate Solutions practices.
Making Sense of the Science: The Nature Conservancy released an article in tandem with the study called “A Natural Path for U.S. Climate Action” that provides a concise summary of the report’s key findings, highlights why pursuing Natural Climate Solutions are important, and introduces the U.S. Natural Climate Solutions Mapper tool, which ranks the potential of NCS pathways within each state.
The Plan for Meeting U.S. Climate Goals
The Biden Administration released The Long-Term Strategy of the United States: Pathways to Net-Zero Greenhouse Gas Emissions by 2050 in November 2021. Chapter 6 of this report, “Removing Carbon Through 2050 and Beyond” highlights several land sector strategies, including avoided conversion of forest land, reforestation, climate-smart forestry practices and agricultural practices that increase soil carbon and projects the carbon sequestration that can be achieved by implementing these practices.
In November 2022, the Biden Administration released its Nature Based Solutions Roadmap, a strategy document that updates federal policies and guidance to making it easier to consider and adopt nature-based solutions; unlock new federal funding to help implement these solutions; train a nature-based solutions workforce; and prioritize, research, innovation, and adaptive learning.
The U.S. Climate Alliance’s 2021 Annual Report, “Further. Farther. Together.” highlights state-level progress toward meeting their climate goals in the Alliance’s member states, and also outlines opportunities for new federal-state partnerships moving forward.
Policies & Practices for Achieving U.S. Climate Goals
The Rhodium Group’s report, Pathways to Paris: A Policy Assessment of the 2030 U.S. Climate Target, plots a policy pathway for achieving U.S. climate goals, focused on policy action that can be undertaken by Congressional legislation, executive action and subnational actors, including actions that can be taken to support carbon sequestration on farms and in forests. The report analyzes the impact of recent legislation on land sector carbon sequestration, as well as potential executive action, like utilizing the Commodity Credit Corporation to support climate-smart management practices.
The U.S. Climate Alliance’s Natural and Working Lands and Climate Action: A State Guide to Enhance the Sector’s Contribution to State and National Climate Goals is a comprehensive guide designed to help states elevate their efforts to reduce land-sector greenhouse gas emissions and maximize carbon sequestration on farms, forests, grasslands, wetlands, and in urban spaces. The guide features dozens of case studies and details federal opportunities that can help states tap into the climate change mitigation potential of their natural and working lands.
A report from the Environmental Defense Fund, Ambitious Climate Mitigation Pathways for U.S. Agriculture and Forestry: Vision for 2030, sets the first science-based targets for reduced emissions from U.S. agriculture and increased carbon storage from U.S. forestry, and identifies the most impactful, lowest-cost pathways to achieve those targets. According to the report, by 2030, U.S. farms and ranches can cut agricultural emissions by 23%, and U.S. forests can boost carbon storage by 43%.
A report by the Center for American Progress, “Nature Loss Threatens America’s Best Defense Against Climate Change,” highlights the important role that efforts to protect and conserve 30% of U.S. lands, waters, and oceans can play in efforts to mitigate climate change – with the potential to remove and store the equivalent of up to 215 million metric tons of carbon dioxide from the atmosphere every year.
The Bipartisan Policy Center’s Farm & Forest Carbon Solutions Task Force Policy Recommendations explores options for jump-starting the rapid scale-up of farm- and forest-based carbon solutions.
Finally, America Is All In’s Blueprint 2030 provides a strategic pathway for achieving the ambitious goals of the United States’ NDC. The “Healthy Lands” section of the report summarizes the benefits of climate smart land management, and highlights the steps that the federal government and subnational actors must take to achieve land sector goals for climate mitigation.
Options for Removing Carbon from the Atmosphere
The Science: The World Resources Institute’s CarbonShot: Federal Policy Options for Carbon Removal in the United States report provides a set of high-priority, near-term federal policy options to advance carbon removal in the United States. The report notes that land-based carbon removal methods like tree restoration and agricultural soil management are the most promising near-term opportunities for carbon removal in the US. The paper analyzes the removal potential of various practices and the cost of implementing these pathways.
Making Sense of the Science: This blog article by the World Resources Institute highlights the top 5 policy actions investments that can be undertaken to support these climate solutions, with a focus on reforestation and farm innovation.
Greenhouse Gas Inventories
The Science: The World Resources Institute’s “Natural & Working Lands Inventory Improvements: A Guide for States” is intended to help advance states’ progress on developing greenhouse gas inventories and evaluate current natural and working land inventory methods in U.S. Climate Alliance states, identifying gaps and providing information and resources to advance improvements to data.
Making Sense of the Science: A complimentary blog article by the World Resources Institute walks through the basics of what a greenhouse gas inventory is, why they are produced, why natural and working lands are included in inventories, and how to improve these inventories for natural and working lands.
Forests: Trees as a Climate Solution
The United States’ 823 million acres of forest lands play a crucial role in our efforts to mitigate climate change. A number of strategies exist to protect and enhance the carbon sequestration potential of America’s forests. This includes replanting historically forested lands, planting more urban trees, improving forest management, and preventing the conversion of existing forests to other land uses. In total, researchers estimate that these forest practices can increase sequestration in our forests and urban areas by 386 million metric tons of carbon dioxide per year.
Protecting existing forests is also a vital component of a comprehensive effort to address climate change. Every time a forest is lost to fire, pests and pathogens, or is cleared for development, some of the carbon stored in its trees is released back into the atmosphere, and our country’s potential to naturally mitigate climate change is reduced. Managing threats to existing forests is an important Natural Climate Solution.
The Inflation Reduction Act (IRA) and Infrastructure Investment and Jobs Act (IIJA), both include substantial investments in forest climate solutions. According to American Forests, the two bills dedicate $14.1 billion for forestry, including forests on city streets, and on both privately- owned and public lands. A data visualization released by American Forests, called Investing in #Forests4Climate, is an excellent resource for decision-makers seeking to better understand the impact of IRA and IIJA on forest climate change mitigation in the U.S. An interactive chart breaks down the funding across a wide array activities and forestry programs, while also estimating the climate change mitigation benefits that will result from this legislation.
Forests can play a major role in addressing climate change by sequestering hundreds of millions of tons of carbon dioxide per year. Science is helping decision-makers and land managers develop better strategies for planting trees, improving forest management, and protecting existing forests from current and future threats.
Where to Put Trees
The Science: Efforts to reforest America should be guided by science-driven decisions on where to plant the trees. Before planting trees, it is important to assess the costs and benefits of reforesting a particular location, while also considering the land’s ownership and whether it was previously forested. The paper “Lower Cost and More Feasible Options to Restore Forest Cover in the Contiguous United States for Climate Mitigation” highlights the important role that tree planting can play as a climate solution in the United States. It examines 10 different opportunities for reforestation and assesses the costs, benefits and feasibility of each approach. The companion Reforestation Hub tool provides data on each of these 10 opportunities at the county level, allowing decision-makers to identify the most practical reforestation options in a given area. Finally, the USDA Forest Service’s Climate Change Tree Atlas models potential habitat for 125 tree species in the Eastern U.S.
Making Sense of the Science: This blog article, written by the paper’s lead author, Dr. Susan Cook-Patton, highlights how the Reforestation Hub can help decision-makers in communities around the country identify the best opportunities for reforesting over 200,000 square miles of land in the United States – an area the size of California and Maine put together.
Combining Climate & Biodiversity Benefits
The Science: In many cases, conserving forests can both mitigate climate change and protect our nation’s rich biodiversity. The Nature Conservancy’s Resilient Lands Mapping Tool and Resilient and Connected Network project helps identify the places where plant and animal species have the best chance to adapt to climate change. A forest carbon analysis recently added to the tool helps policy makers identify lands for conservation that have both high potential for both carbon storage and biodiversity conservation.
Making Sense of the Science: This article, written by The Nature Conservancy’s Mark Anderson – the scientist who has led this effort – explains how decision makers can use the carbon layer recently added to the Resilient Lands Tool to target specific areas for conservation that have both value for biodiversity and for carbon storage.
Building Capacity for Reforestation
The Science: Recognizing the important role that forests can play in addressing climate change, ambitious efforts to reforest America are underway. Unfortunately, limitations in seedling production and workforce capacity may hinder these efforts. A recent paper by Fargione et al., “Challenges to the Reforestation Pipeline in the United States” delves into these issues, identifying a need to more than double tree nursery capacity in the U.S. to achieve our reforestation ambitions. The paper also outlines potential solutions for overcoming the capacity and workforce challenges that serve as barriers to reforestation.
Making Sense of the Science: A blog article entitled “Seeing the Forest for the Seedlings: Challenges and Opportunities in the Effort to Reforest America,” written by co-author Diane Haase, frames the findings of Fargione et al.’s “Reforestation Pipeline” paper through the lens of her own experience as a nursery specialist with the USDA Forest Service – highlighting the need to increase nursery capacity and build a reforestation workforce.
Science in Action: A recent video produced by U.S. Nature4Climate spotlights the story of Minnesota’s Chelsea Morning Farm, which is part of a collaborative effort that has brought together farmers, non-profit organizations and universities to strengthen capacity for reforestation, while also ensuring that trees can thrive in a changing climate. Another USN4C video highlights the MANO Project, a collaboration between the Hispanic Access Foundation and several U.S. federal agencies to build the diverse workforce necessary to protect public lands and implement just and equitable climate change mitigation strategies.
Planting Urban Trees
The Science: Urban trees not only help sequester carbon, but can also provide significant benefits to urban communities, including relief from heat, lower energy bills, improved resilience to flooding and increased opportunities for outdoor recreation. However, recent work by American Forests and The Nature Conservancy highlights disparities in tree cover in both low-income neighborhoods and communities of color. American Forests’ Tree Equity Score assesses the distribution of tree cover in neighborhoods nationwide, indicating whether there are enough trees in a neighborhood for everyone to experience the health, economic and climate benefits that trees provide. American Forests finds that we need to plant 522 million trees in cities to reach full Tree Equity nationwide. The Nature Conservancy’s study found that low income blocks have 15.2% less tree cover and are 1.5℃ hotter than high-income blocks in urbanized areas, with even greater disparities in some regions. Another American Forests report estimates that by planting 31.4 million urban trees per year at a cost of $8.9 billion dollars, we can create 228,000 new jobs and remove carbon from the atmosphere equal to 200,000 cars per year.
Making Sense of the Science: A U.S. Nature4Climate blog article, “Investing in America’s Urban Forests,” summarizes the key findings of both the American Forest and The Nature Conservancy’s research, highlighting the potential of urban trees to both mitigate climate change and reduce inequality in U.S. cities. American Forests’ Tree Equity Score tool also provides a useful map for decision-makers to address disparities in tree cover by targeting urban forestry resources to the neighborhoods most in need of relief. This video produced by U.S. Nature4Climate highlights the Boise City of Trees Challenge, an effort to plant one urban tree for every household in Boise, Idaho, while also ensuring the threes survive and thrive well into the future. The program utilizes the Tree Equity Score tool to ensure that trees benefit the communities that need them most.
The Trust for Public Land’s special report, The Power of Parks to Address Climate Change, highlights the powerful role that parks can play in mitigating climate change and helping communities adapt to its impacts, while also providing benefits to disadvantaged communities.
How to Plant Trees
The Science: A report recently released by The National Wildlife Federation, American Forests and The Nature Conservancy, “Toward a Shared Understanding of Climate-Smart Restoration on America’s National Forests,” reviews and summarizes recent scientific insights into how climate change is affecting America’s national forests and how climate-smart forest restoration can help sustain these cherished public lands. The report goes on to identify and explore eight proposed principles for climate-smart forest restoration to guide restoration efforts.
Making Sense of the Science: A companion publication to the Climate-Smart Restoration report, “Restore Forests for the Future: Profiles in Climate-Smart Restoration on America’s National Forests,” explores how the principles of climate-smart forest restoration are being put into practice throughout the U.S. to manage and restore landscapes. It includes a number of case studies highlight how these principles help improve management of fire-prone forests, optimize the carbon sequestration potential of forest lands, and reduce climate risk.
Improving Forest Management
The Science: Improving forest management offers another pathway for mitigating climate change. This can include changing timber harvest practices, restoring forest health and resilience, and other actions that support sustainable forestry. A paper called “Improved Forest Management as a Natural Climate Solution” – co-authored by scientists from the USDA Forest Service, The Nature Conservancy and several universities – summarizes the climate mitigation potential of practices like extending timber harvest rotations, selective harvesting, thinning and post-harvest regeneration. The paper highlights a need to better define forest management practices and develop a stronger base of evidence on their efficacy, suggests a greater focus on forest soil carbon, and recommends steps to make improved forest management practices (IFM) more accessible for landowners.
Ongoing research by American Forests on forest management and carbon impacts emphasizes the importance of a systems-based approach to forest management, considering the carbon impacts not only in the forest but also in harvested wood products and other sectors of the economy. This research also shows that a broad range of management practices, such as extending harvest rotations, optimizing stocking levels, and promoting natural regeneration, are viable climate mitigation strategies in certain regions.
Making Sense of the Science: The Family Forest Carbon Program, a joint program of the American Forest Foundation and The Nature Conservancy, incorporates the lessons learned in the research noted above. The program helps make IFM programs more accessible to family forest owners by providing financial assistance, professional expertise, and creating a new carbon accounting methodology that helps verify that carbon projects are sequestering additional carbon. This TNC video explains how the Family Forest Carbon Program works.
Pests & Pathogens
The Science: A recent paper, “Insect and Disease Disturbances Correlate With Reduced Carbon Sequestration in Forests of the Contiguous United States,” highlights the threats to existing forests posed by both invasive and native pests and their impact on forest carbon stocks, finding that forests damaged by insects sequestered 69% less carbon, and those damaged by disease sequestered 28% less carbon, when compared to forests not impacted by one of these severe disturbances. The paper also outlines policy options as well as steps that can be taken to mitigate these threats.
Making Sense of the Science: A blog article written by co-author Leigh Greenwood summarizes the pests and pathogens paper’s findings and argues that addressing the threats posed by both invasive pests and native pests is vital if we want to protect both forest carbon stocks and the diverse plant and animal species that inhabit U.S. forests. This will require implementation of sustainable land management practices and preventive strategies to keep invasive pests from becoming established in the U.S.
The Science: A study recently released by Clark University, “Avoided Deforestation: A Climate Mitigation Opportunity in New England & New York,” quantifies the significant challenges posed by deforestation in our efforts to mitigate climate change. The report calculates the amount of forest lost each year in New York and New England, along with the carbon released by deforestation and the amount of future carbon storage lost. The results of this research can help land managers plan conservation programs that help minimize forest loss.
Making Sense of the Science: This article written by The Nature Conservancy’s Massachusetts chapter highlights how decision-makers are using the results of Clark University’s study, coupled with hands-on tools like the Resilient Lands Mapping Tool, to target vulnerable forest lands for conservation and undertake management activities – like tree planting, thinning and removing invasive species – to keep forests healthy.
The Science: Increasingly frequent and severe wildfires release huge amounts of carbon – previously stored in living trees – back into the atmosphere. The USDA Forest Service’s Fire Research website links to several of the Agency’s efforts to better understand wildfire behavior. A paper co-written by scientists from Colorado State University and the Forest Service’s Rocky Mountain Research Station, “Forest Service Fire Management and the Elusiveness of Change,” highlights a need to better integrate fire and land management planning, increase stakeholder collaboration and improve training of agency personnel.
Making Sense of the Science: A recent article in American Forests Magazine called “The United States of Fire” details how past forest management practices have made us more vulnerable to catastrophic fires and highlights efforts the state of Florida has taken to improve the resilience of its forests to fire. This video by The Nature Conservancy illustrates how carefully controlled burns can help lessen the risk of catastrophic wildfire. The Bipartisan Policy Center’s blog article, “Building American Wildfire Resiliency,” summarizes current approaches to managing wildfire, recent Congressional action to address wildfire threats and recommendations for future action.
Climate Change Adaptation
The Science: Making U.S. forests more resilient to a changing climate is another important strategy for addressing climate change. Trees adapted to thrive under current conditions may suffer in warmer environments. The paper “Forest Management for Carbon Sequestration & Climate Adaptation” identifies a need to adapt existing forests to a changing climate, and recommends a “Forest Carbon Management Menu” to guide these efforts. The menu also highlights synergies between climate change mitigation and adaptation – removing carbon from the air while also increasing the resilience of our lands and communities to climate change.
Making Sense of the Science: The Climate Change Response Framework’s Forest Carbon Management website provides a high-level walkthrough of the paper recommended above, highlights real-world examples of climate adaptive forest management, and links to “A Quick Guide to Adaptation Planning For Natural Resources Professionals,” a resource developed by the U.S. Department of Agriculture’s Northern Forest Climate Hub that serves as a step-by-step guide to assist decision-makers in forest adaptation planning.
Agricultural Lands: Making Farms & Ranches Part of the Solution to Climate Change
Agricultural lands can be an important part of the solution to climate change. Climate-smart agricultural practices can increase the amount of carbon sequestered and stored in the ground and reduce greenhouse gas emissions. It is also important to avoid the conversion of farmland to development and reduce conflict between agriculture and renewable energy through smart siting of solar energy development. Emerging practices like agroforestry, biochar and long-rooted perennials also have potential to significantly increase carbon sequestration on agricultural lands. The U.S. Department of Agriculture’s Climate Solutions website provides a good overview of actions underway to help implement climate-smart strategies on America’s farms.
Climate-smart agriculture practices can sequester and store carbon in the ground, while reducing greenhouse gas emissions. America’s farmers and ranchers are working with scientists, policy makers and businesses to develop innovative, win-win solutions that are good for our environment and our economy.
Fundamentals of Soil Health Science
The Science: U.S. Farmers and Ranchers in Action’s Climate Smart Agriculture: An Overview for Corn-Soybean Systems report is a comprehensive literature review that walks through the fundamentals of soil health. It links climate-smart agriculture to additional benefits for farmers, including improved productivity and soil resilience, and the important role testing and monitoring play in maintaining healthy soil.
Making Sense of the Science: U.S. Farmers & Ranchers in Action’s Nutrient Cycling Resource Center webpage includes short summaries for each of the report’s four chapters, as well as helpful infographics that illustrate the role that the carbon cycle, water cycle and nitrogen cycle play in maintaining healthy soil. The Dairy Feed in Focus program, spotlighted by U.S. Nature4Climate in this video, shows how Wisconsin and Michigan farmers, working together with The Nature Conservancy and companies, are leading efforts to research and implement climate-smart agricultural practices on Midwestern dairy farms.
Understanding the Importance of Soil Health
The Science: The Nature Conservancy’s “reThink Soils: A Roadmap to U.S. Soil Health” report summarizes the impact that degradation of soils has had on U.S. agriculture, and summarizes the benefits of healthy soil, including increased agricultural productivity and improved storage of nutrients and water. Healthy soil also has the potential to mitigate 25 million metric tons of carbon emissions – equivalent to removing 5 million cars from the road for a year. The report also provides a roadmap to overcoming research gaps and economic barriers that constrain adoption of soil health practices, while suggesting policy actions that can help overcome these barriers.
Making Sense of the Science: A blog article published by The Nature Conservancy provides a high-level overview of the reThink Soils report finding. A short, animated video walks through the reThink Soil Initiative and highlights actions that have been taken to further research, policy and practice around soil health.
Cover Crops and No-Till
The Science: U.S. agricultural land has the potential to be a key part of the solution to climate change. Climate-smart agricultural practices like cover cropping and nutrient management can help both store carbon and reduce carbon emissions. American Farmland Trust’s Combating Climate Change on US Cropland report summarizes the state of the science on the potential carbon sequestration impacts of cover cropping and no-till agriculture, identifies barriers farmers face in implementing these practices, offers suggestions on how to overcome these challenges, and recommends a path forward for implementing cover cropping on an additional 15% of cropland acres, while converting 25% of current acres to no-till.
Making Sense of the Science: The American Farmland Trust’s Brandon Hafner wrote blog article called “New Research Shows the Incredible Potential of America’s Agricultural Soils to Combat Climate Change,” offering a brief summary of the report’s key findings. The “Debate and Discussion” section of this website features an in-depth discussion by experts on the challenges, and opportunities of implanting no-till agriculture, and the uncertainties that scientists are trying to address.
Economics of Climate-Smart Agriculture
The Science: Several works have been released recently that quantify the economic benefits of climate-smart agriculture. The Soil Health Institute’s Economics of Soil Health Systems research interviewed 100 farmers and conducted partial budget analysis on their farms to quantify the costs and benefits of implementing soil health systems, finding increased income for 85% of corn farmers and 88% of soybean farmers. Their website includes a fact sheet and webinar that highlight the reports key findings. Research conducted by the American Farmland Trust found similar findings, showing increases in crop yields, profits and a significant return on investment for farmers implementing soil health practices like cover crops, no-till cropping, and nutrient management practices.
Making Sense of the Science: A blog article published in the Environmental Defense Fund’s [EDF] “Growing Returns” blog summarizes the findings of the Soil Health Institute’s work and provides links to additional research focusing on the impact soil health has on crop resilience. American Farmland Trust’s Soil Health Case Studies landing page links to nine 2-page case studies highlighting the impact that implementation of soil health practices had on 9 farms in California, Illinois, New York, and Ohio.
A new collaboration between EDF and the Farmers Business Network, the Regenerative Agriculture Finance Fund “rewards farmers with lower interest rates who meet climate and water quality benchmarks”.
The Science: Implementing climate-smart management practices on agricultural land can play a powerful role in mitigating climate change. However, this opportunity is being lost as U.S. farmland and ranchland is converted to developed land uses. Indeed, American Farmland Trust’s [AFT] Farms Under Threat Report notes that 11 million acres of U.S. agricultural land were converted to developed land uses between 2001 and 2016. In addition to quantifying the threats to agricultural land, the report offers a menu of both state and federal-level policy options that can help keep agricultural land in production.
AFT’s “Greener Fields” report quantifies the climate benefit of avoiding conversion of farmland in New York, noting that farmland emits 66 times fewer greenhouse gases per acre than developed land in the state.
Making Sense of the Science: To help decision-makers navigate this issue, American Farmland Trust created a spatial mapping tool that highlights the scale of conversion of agricultural land to developed land uses, and where conversion is most prevalent. The Agricultural Land Protection Scorecard assesses state-level action to address farmland loss, measures their performance, and highlights policy actions in each state that have been effective in addressing the problem.
Agrivoltaics & Solar Siting
The Science: An comprehensive strategy to address climate change requires efforts to reduce emissions and develop sustainable energy sources, as well as Natural Climate Solutions. Smart siting of renewable energy ensures that solar energy development does not result in the loss of carbon-sequestering farmland and forests. Dual-use solar, also called “agrivoltaics” is the practice of siting solar panels on farmland in a way that allows agricultural activities to continue.
A study spearheaded by Oregon State University suggests that investing in agrivoltaics can create jobs, reduce carbon emissions and help farmers continue farming. A study by the Yale Center for Business & The Environment titled “Maximizing Land Use Benefits From Utility Scale Solar” provides a cost-benefit analysis of pollinator-friendly solar development in Minnesota, highlighting additional benefits provided by these projects, including higher crop yields, reduced soil erosion and increased groundwater recharge.
Making Sense of the Science: The American Farmland Trust (AFT) has created a Solar Siting webpage that offers resources for farmers and policy-makers to navigate the smart-siting of solar energy development and identify opportunities for dual-use solar. AFT’s Smart Solar Siting Partnership for New England offers a real-world example of these principles being put into action. A U.S. Nature4Climate blog article highlights another effort – the Long Island Solar Roadmap report and online mapping tool – that is helping to ensure that solar energy development on Long Island does not adversely impact existing farms, forests and parks. Finally, this article by the Environmental and Energy Study Institute highlights efforts to support the planting of pollinator-friendly habitat on solar energy sites.
The Science: Agroforestry is “the intentional integration of trees and shrubs into crop and animal farming systems to create environmental, economic and social benefits. The U.S. Department of Agriculture’s National Agroforestry Center’s Agroforestry Brief summarizes a variety of agroforestry practices, including alley cropping, windbreaks, riparian forest buffers, silvopasture and forest farming, describing each and listing their climate, environmental and economic benefits. The brief links to a number of additional resources on the science of agroforestry, including a study called “Branching Out: Agroforestry as a Climate Change Mitigation and Adaptation Tool for Agriculture,” that takes a deeper dive into the climate benefits of agroforestry.
Making Sense of the Science: The Savanna Institute’s website highlights the climate benefits of agroforestry, noting that globally, “agroforestry could sequester 2.2 gigatons of carbon per year – more than any other agricultural land management approach out there.” The website also offers a series of infographics that outline the benefits of 5 agroforestry practices and provide answers to frequently asked questions. A report by the World Resources Institute quantifies the potential job benefits of agroforestry, noting that an annual federal investment of $1.8 billion dollars annually could support 49,500 jobs each year.
Science in Action: This video on agroforestry produced by U.S. Nature4Climate spotlights the efforts of Iowa farmers Kathy Dice and Tom Wahl to integrate agroforestry into their farming practices – sequestering carbon while also diversifying their income.
The Science: Biochar is produced from agricultural and forestry waste in a controlled process called pyrolysis. One study suggested amending soils with biochar produced from available agricultural and forestry waste could sequester up to 95 million metric tons of carbon dioxide, while also improving soil’s capacity to hold moisture. Biochar can also improve carbon sequestration in forest soils. A study co-authored by scientists from the University of Idaho and U.S. Department of Agriculture found that adding biochar to forest soils increased soil carbon content by 41% without affecting tree growth. A paper recently released by the Foundation for Food & Agriculture Research, the National Center for Appropriate Technology, and American Farmland Trust, Scaling Sustainable Biochar Research & Commercialization for Agriculture & Conservation: A Summary from a Stakeholder Convening, summarizes how sustainably produced and applied biochar can reduce greenhouse gas emissions and build healthy high functioning soils, while also outlining research needs and gaps to help scale up implementation.
Making Sense of the Science: Nature4Climate’s biochar page explains what biochar is and the impact it can have on global emissions. The Climate Action Reserve is currently working on a protocol that would allow for the sale of carbon credits based on the production and use of biochar. An article on the U.S. Nature4Climate blog, Sequestering Carbon Through Conversion and Community Burning: Converting Forest Fuels to Biochar, highlights a project undertaken by the Lands Council and Kalispel Tribe to turn slash piles produced by forest thinning efforts into biochar, which can be applied to agricultural soils to improve water holding capacity and increase carbon sequestration.
Long-Rooted Perennial Crops
The Science: Long-rooted perennial crops have the potential to store significantly more carbon in the soil than other crops. The World Resources Institute’s CarbonShot report suggests that investing in the development of these crops could serve as an important agricultural carbon solution, but that challenges exist in maintaining crop yields and taste. The Land Institute (TLI) is working to overcome these challenges through the development of Kernza, a long-rooted perennial grain crop that stores significantly more carbon in the soil than other crops. Last year, they released a white paper – “Perennializing Grain Crop Agriculture: A Pathway for Climate Change Mitigation & Adaption” – that analyzes both the benefits and challenges of scaling up perennial grain crops.
Making Sense of the Science: The Land Institute’s website provides a good high-level summary of the role perennial crops can play in addressing environmental problems, including climate change. TLI’s Kernza website provides additional resources for a variety of stakeholders to learn more about the grain. A recent article in the Washington Post profiles The Land Institute’s efforts to develop Kernza and their partnerships with farmers to plant the grain on working farms, through the perspective of the reporter’s experience in making a loaf of Kernza-based bread.
Science in Action: This video produced by U.S. Nature4Climate and complementary blog article focuses on The Land Institute’s work to develop Kernza, a long-rooted perennial grain, as well as efforts by Perennial Pantry, a Minnesota business dedicated to developing Kernza-based products that can be used in kitchens throughout America. This USN4C blog article highlights how the Forever Green Initiative in Minnesota is bringing together farmers, government agencies, private businesses, non-profits, and research organizations to develop and scale implementation of Kernza and other perennial grains – supported by permanent funding allocated by the Minnesota Legislature.
Climate-smart feed for livestock
The Science: According to the Environmental Protection Agency, methane produced by the digestive processes of livestock, especially cattle, is responsible for over a quarter of the greenhouse gas emissions produced by the U.S. agriculture sector. One study led by scientists from the University of California-Davis and Stanford University, found that adding a marine algae to livestock feed has the potential to reduce these methane emissions by over 50%.
Making Sense of the Science: An article on the UC-Davis website discusses the impact that livestock has on global emissions and walks through the findings of the research cited above, noting that adding seaweed to cow diets reduces emissions without changing the flavor of the milk.
The Science: Biological soil crusts (biocrusts) are a surface community of lichens, mosses, cyanobacteria, and related organisms living on soils worldwide. Biocrusts occur on all continents and a recent global estimate says that biocrusts cover about 12% of the Earth’s total land surface. Biocrusts are particularly common in arid and semi-arid ecosystems, such as in the deserts of the southwestern United States. As this article by The Nature Conservancy notes, biocrusts are threatened by human activity, animals, and rising temperatures caused by climate change. The U.S. Geological Survey is studying how livestock grazing impacts biocrusts, as well as steps that can be taken to protect these soils.
Making Sense of the Science: A blog article written by the team at The Nature Conservancy Utah’s Canyonlands Research Center, Innovative Biocrust Restoration Technique Offers Hope in a Warming Climate, highlights efforts by scientists to research cutting-edge techniques to restore biocrusts, which play a crucial role in stabilizing soils and retaining moisture, boosting desert soil fertility, and storing carbon.
Blue Carbon: Wetland & Marine Ecosystems Storing Carbon Efficiently & Effectively
Blue carbon refers to the greenhouse gasses captured and stored by coastal wetlands, as well as ocean ecosystems. Protecting and restoring blue carbon ecosystems including seagrasses, salt marshes, tidal forests and mangroves helps mitigate climate change while also supporting climate adaptation and resilience strategies by lessening the impacts of rising seas, damaging storms and ocean acidification. Although these ecosystems represent a relatively small percentage of the total U.S. land area, they can sequester and store significantly more carbon per unit area than terrestrial forests, and if left undisturbed can store this carbon for millennia.
One study estimated that each acre of coastal wetland is capable of sequestering 10 times more carbon than tropical forests. Coastal wetlands in the Pacific Northwest, such as tidal swamps, store carbon at rates comparable to the region’s old growth forests. In addition, blue carbon strategies offer a multitude of co-benefits, such as increased resilience to storms and flooding, improved water quality, protection of wildlife – including commercially and recreationally valuable fish populations – economic benefits for coastal communities, and conservation of areas important for cultural and spiritual practices. The climate mitigation potential coupled with the significant co-benefits provided by coastal blue carbon habitats is a major reason why states like Oregon, California, Louisiana, New Jersey and Maine are working to incorporate blue carbon solutions into their climate change mitigation planning.
Although seagrasses, salt marshes, tidal forests, and mangroves represent a small percentage of U.S. lands, they sequester a disproportionately large amount of carbon. Scientists are developing ways to protect and restore these ecosystems, and are studying new and studying future opportunities for storing carbon in our oceans.
Understanding Blue Carbon
The Science: The National Oceanic and Atmospheric Administration (NOAA) has several resources related to blue carbon, including a coastal blue carbon primer, a recently published report called “A Guide to Understanding and Increasing Protection of Blue Carbon,” and a companion case study that provides in-depth information on a number of blue carbon strategies. Another paper, “The Role of Blue Carbon in Climate Change Mitigation and Carbon Stock Conservation” also reviews the various types of blue carbon ecosystems, outlining the benefits of blue carbon restoration, the debate over how to value these benefits, and the governance and financing challenges that must be overcome to implement blue carbon solutions.
The Blue Carbon Brief, written by Conservation International, the Pew Charitable Trusts, the Nature Conservancy and a host of other organizations, explores both coastal blue carbon strategies, as well “emerging” oceanic blue carbon ecosystems, including kelp farming, phytoplankton and even fish, explaining that to take advantage of these opportunities in the future, the scale of carbon removal must be significant, carbon must be stored long term, and methodologies must exist to account for the amount of carbon sequestered – a criteria that has not yet been satisfied by these strategies.
State of the Science in the U.S.: The Smithsonian Environmental Research Center, which curates the Coastal Carbon Atlas, the world’s largest database of blue carbon information, analyzed the state of blue carbon research in the lower 48 and offered recommendations for improvement in this report.
Making Sense of the Science: The Blue Carbon Initiative’s website provides a high-level overview of blue carbon’s potential as a climate mitigation strategy, and details the work of its Scientific and Policy Working Groups to develop the science and policy frameworks needed to support broad implementation of blue carbon strategies. The Pew Charitable Trusts’ issue brief, “Coastal ‘Blue Carbon’: An Important Tool for Combating Climate Change,” provides basic information on the climate, economic, and environmental benefits of coastal ecosystems and highlights action that the federal government and states can do to help protect and restore coastal wetlands. This article by the Environmental Defense Fund summarizes the uncertainties around oceanic blue carbon, highlighting the need for investment in science to better understand their viability as a climate solution. An analysis by the Ocean & Climate Platform highlights the positive climate mitigation impacts of marine protected areas, including both coastal and oceanic blue carbon ecosystems. A report by the Center for American Progress recommends investing in blue carbon ecosystems as part of broader efforts to strengthen the U.S. Marine Sanctuaries Program.
Salt Marsh and Tidal Wetland Restoration
The Science: Salt marshes and estuaries provide habitat for wildlife, protection from coastal communities from floods, opportunities for recreation, improved water quality and carbon storage. This overview by the U.S. Geological Survey focuses on efforts to document the benefits of wetlands for wildlife and carbon sequestration, with an eye toward designing conservation projects that achieve both goals. Restore America’s Estuaries’ Blue Carbon Science & Projects webpage also provides an overview of the carbon sequestration potential of coastal wetlands, as well as links to blue carbon estuary assessments in Tampa, Florida and Galveston Bay, Texas.
Making Sense of the Science: This U.S. Nature4Climate blog article profiles a partnership between the Gullah/Geechee community, military leaders and federal, state and local governments to conserve a million acres of saltmarsh on the Southeast Atlantic Coast. An article in Yale Environment 360 spotlights an effort to restore a degraded salt marsh on the Delaware coast. This report by the Pew Charitable Trusts and a coalition of organizations highlights how blue carbon science has been incorporated into Oregon’s efforts to integrate natural and working lands into their climate planning. Finally, this article in the Yale Environmental Review highlights how reconnecting blocked tidal marshes to the ocean can help methane emissions.
Science in Action: This video and companion blog article produced by U.S. Nature4Climate focuses on the work an organization called WILDCOAST is doing in the San Diego area to restore coastal wetlands and measure the climate impact of their restoration efforts.
Another USN4C video spotlights the Lighting Point Shoreline Restoration Project in Bayou La Batre, Alabama – a broad a broad partnership, led by The Nature Conservancy, that has improved the city’s resilience to hurricanes by restoring coastal wetlands and making infrastructure improvements. By restoring these wetlands, the community has also increased carbon storage, improved wildlife habitat, and supported the local fishing economy. This successful program, which has already heled protect Bayou La Batre from multiple hurricanes, can serve as a model for building climate resilience in communities throughout the Gulf Coast.
The Science: Eelgrass is a seagrass that exists in shallow bays and estuaries around the world. In addition to sequestering carbon, eelgrass helps reduce coastal erosion and provides food and habitat for fish, birds and other marine species. New research indicates that eelgrass can also provide localized amelioration of ocean acidification, a climate impact that is changing the chemistry of the ocean and poses threats to fisheries. The Eelgrass Restoration Synthesis published by the Pacific Marine & Estuarine Fish Habitat Partnership focuses on the steps that need to be taken to ensure success in seagrass restoration projects – finding that location had more impact on project success or failure than restoration methods. The synthesis also includes links to case studies.
Making Sense of the Science: This article by the Pew Charitable Trusts walks through the key findings of the Eelgrass Restoration Synthesis cited above. This piece produced by The Nature Conservancy’s Virginia Chapter provides an in-depth look at a real-world eelgrass restoration effort.
The Science: Mangrove swamps are found along the U.S. Gulf Coast. Mangrove trees, which can survive in both saltwater and freshwater, support a wide array of wildlife, and can sequester 10 times more carbon than terrestrial forests. This article by the National Science Foundation profiles a study calculating that the value of stored carbon in mangrove trees in Florida’s Everglades is between $2.0-$3.4 billion. Knowing this value can help decision-makers better navigate the costs and benefits of restoration programs. Another report by The Nature Conservancy and the University of California Santa Cruz complements this work by valuing the flood reduction benefits of Florida’s mangroves.
Making Sense of the Science: An article by the Pew Charitable Trusts, “Mangrove Protection Can Provide Conservation Wins,” details what mangroves are, why they are important not just for biodiversity, but also for climate change adaptation and mitigation – protecting shorelines from erosion and flooding. An article by The Nature Conservancy’s Florida Chapter reinforces the benefits of mangroves, the threats they are facing due to human impacts, and includes a short video showing how mangroves protect coastlines from storm surges.
Blue Carbon Offsets
The Science: Carbon offset credits can help provide a mechanism for funding coastal restoration projects; however, research is necessary to establish the accounting and verification protocols to implement these credits. Scientists at the University of Virginia are conducting research to accomplish this goal. Their paper, “The Greenhouse Gas Offset Potential from Seagrass Restoration,” examined the carbon sequestration potential and possible financial benefit of eelgrass restoration focusing on research done at the Virginia Coast Reserve. A brief by Restore America’s Estuaries also speaks to efforts to incorporate blue carbon projects into voluntary carbon markets.
Making Sense of the Science: The University of Virginia’s Environmental Resilience Institute published a short explainer of university’s work on blue carbon credits. An article in Forbes Magazine highlights work this team has done on Virginia’s barrier islands to study the feasibility long-term carbon credits for eelgrass restoration projects.
In addition to the blue carbon strategies outlined above, some freshwater wetlands also have the potential to play a significant role in mitigating climate change.
The Science: Peatlands are known by many names (e.g., mire, marsh, swamp, fen, bog), but can simply be defined as a class of wetlands with a naturally accumulated layer of peat. Peat is formed when organic matter accumulates faster than it decomposes due to the lack of oxygen in waterlogged conditions.
Even though peatlands cover only 3% of Earth’s surface, they store more than twice as much carbon as the world’s forests. This issue brief by the International Union for the Conservation of Nature explains what peatlands are, the threat posed by destruction of peatlands, and actions that can be taken to protect, manage and restore peatlands.
Making Sense of the Science: An article in the journal Nature called “How Peat Could Protect the Planet” profiles peatland restoration efforts in Scotland. The article discusses the important role peatlands play as a carbon sink and the growing threats to these ecosystems. The U.S. Fish & Wildlife Service’s fact sheet, “Carbon Sequestration Benefits of Peatland Restoration” includes a case study of a peatland restoration effort at Pocosin Lakes National Wildlife Refuge. An article published by the Pew Charitable Trusts, called “Peatlands, Which Can Fight Climate Change, Face Many Threats,” highlights the role science can play in helping to conserve peatlands.