Twenty miles upstream of Portland, Maine, lies Sebago Lake, the state’s deepest and second-biggest body of water. The lake provides drinking water to 16 percent of Maine’s population, including residents of Portland, the state’s largest city. It holds nearly a trillion gallons of clear, cold water. Portland’s water utility has earned one of only 50 federal filtration exemptions in the country, which means the water, although treated to ward off microorganisms, does not have to be filtered before it flows into the city’s taps.  

“The primary reason it’s so pure is that most of the watershed is still forested,” says Karen Young, director of Sebago Clean Waters, a coalition working to protect the area. Eighty-four percent of the 234,000-acre watershed is covered in forests—a mix of pine, oak, maple, and other species that filter water and help make this system work so well. But those forests face threats. Between 1987 and 2009, the watershed lost about 3.5 percent of its forest cover. Just 10 percent of the area was conserved. In 2009, 2014, and 2022, the U.S. Forest Service ranked the Sebago watershed as one of the nation’s most vulnerable, due to threats from development.  

Over the last couple of decades, conservation groups began to worry about the future of this critical resource—and the Portland Water District (PWD) was worried, too. An independent utility that serves more than 200,000 people in Greater Portland, PWD purchased 1,700 acres around the water intake in 2005 and adopted a land preservation policy in 2007. In 2013, it established a program to help support conservation projects undertaken by local and regional land trusts. 

Most of these organizations were working independently until 2015, when The Nature Conservancy brought them together to develop a conservation plan for the lake’s largest tributary, the Crooked River. That convening evolved into the Sebago Clean Waters coalition, which includes nine local and national conservation groups, the water district, and supporters from the business community. As they explored creative ways to protect the lake and the land around it, the idea of creating a water fund surfaced. 

Water funds are private-public partnerships in which downstream beneficiaries like utilities and businesses invest in upstream conservation projects to protect a water source—and, by extension, to ensure that the supply that reaches users is as clean and plentiful as possible. In 2016, Spencer Meyer of the Highstead Foundation—one of the groups that founded Sebago Clean Waters—took a trip to Quito, Ecuador, with The Nature Conservancy. The group visited with representatives of the Fund for the Protection of Water for Quito (FONAG), a leading example of this novel source water protection model. Meyer saw some similarities to the situation in Maine. 

“We thought, ‘What if we could bring the partners together as a whole system to accelerate the pace of conservation?’” he says. “And could we apply that model to a healthy watershed, to take a proactive position and build this financial model in a place where it isn’t too late?” 

A water fund is a financial tool, but it’s also a governance mechanism and management framework that brings multiple stakeholders to the table. Quito’s fund, launched in 2000, is the longest-standing one in the world. Similar projects have proliferated across the globe, particularly in Latin America and Africa. According to The Nature Conservancy, more than 43 water funds are operating in 13 countries on four continents, with at least 35 more in the works. 

The Importance of Healthy Watersheds 

Globally, clean water is our most important resource. When upstream watersheds are healthy, they collect, store, and filter water. That provides a resource that can, in addition to meeting basic hydration and sanitation needs, support climate change adaptation, food security, and community resilience. When watersheds are not healthy, sediment clogs up water filtration systems, pollutants flow downstream, and ecosystems become degraded. 

That difference is crucial. According to a Nature Conservancy report, more than half the world’s cities and 75 percent of irrigated agriculture are likely already facing recurring water shortages. Climate change is fueling extreme drought, from the U.S. West to Australia, and pollution from sources like nitrogen and phosphorus has grown ninefold in the last half century. In many cities, the source of water is far away and under different jurisdiction, which makes regulation and treatment challenging. 

The Nature Conservancy also estimates that 1.7 billion people living in the world’s largest cities currently depend on water flowing from fragile source watersheds hundreds of miles away. That puts strain on both ecological systems and infrastructure, and demand is only growing. By 2050, two-thirds of the global population will live in those cities. That level of demand simply may not be sustainable, especially in a rapidly changing climate. Water funds can be creative, multilayered solutions to two urgent, interlocking issues: water quality and quantity. 

“Water funds sit at the intersection of land, water, and climate change,” says Chandni Navalkha, associate director of Sustainably Managed Land and Water Resources at the Lincoln Institute of Land Policy. “They are an example of the kind of cross-sectoral, multi-stakeholder governance and collaboration that is required to maintain water security in a changing climate.” 

Navalkha recently oversaw the development of a case study of the Sebago Clean Waters initiative, which the Lincoln Institute will distribute through its International Land Conservation Network. Changing the way water has been historically managed isn’t easy, particularly because it’s tangled up in issues like city planning, economic growth, and public health. So groups like the Lincoln Institute and The Nature Conservancy are working to spread the water fund model by showing the science behind source water protection, giving communities tools to find ecosystem-specific solutions, and sharing the experiences of places like Portland and Quito. 

Lessons from Quito 

In the late 1990s, officials in the Metropolitan District of Quito started to worry that they were running out of water to support the city’s 2.6 million residents. The upstream ecosystems that filled the city’s aquifers were eroding, and those impacts were trickling downstream. 

A full 80 percent of the city’s water supply originated from protected areas within its watershed: the Antisana Ecological Reserve, Cayambe Coca National Park, and Cotopaxi National Park. “But they were only paper parks,” says Silvia Benitez, who works for The Nature Conservancy as water security manager for the Latin American Region. Instead of being protected, the area’s páramos—biodiverse high-altitude grasslands that are home to a range of rare endemic species and filter the upstream water supply—were facing multiple threats from livestock grazing, unsustainable agriculture, and construction. 

Where conservation was an option, lack of funding made it difficult to achieve. Benitez says water managers knew the situation needed to be addressed, so the Municipal Sewer and Potable Water Company of Quito and The Nature Conservancy set up a fund to support the upstream ecosystem with $21,000 in seed money. Over the next four years they built a board of public, private, and NGO watershed actors, including Quito Power Company, National Brewery, Consortium CAMAREN, which provides social and environmental policy training, and the Tesalia Springs Company, a multinational beverage corporation. All of those stakeholders had a vested interest in water, and each contributed to the trust every year. 

Today, FONAG is regulated by the Securities Market Law of Ecuador and has a growing endowment worth $22 million. That funding is used to support upstream environmental projects like agricultural training and plant restoration in the páramos, which helps limit sedimentation. 

“It’s a financial mechanism that harnesses investments from private and public sectors to protect and restore forests and ecosystems,” says Adriana Soto, The Nature Conservancy’s regional director for Colombia, Ecuador, and Peru. It’s also a forward-thinking way to manage water, says Soto, who was previously vice minister of Environment and Sustainable Development of Colombia and serves on the board of the Lincoln Institute.  

Traditional water infrastructure—often called gray infrastructure—consists of pipes, water filtration systems, and chemical treatments, which are designed to purify water before it’s used. Gray infrastructure has long been relied on to ensure that water was potable and accessible. But it’s expensive and energy intensive, it can negatively impact wildlife and ecosystems, and it breaks down over time. Climate change is also posing threats to gray infrastructure; for instance, intensifying wildfires have led to increased sedimentation that chokes existing filtration plants, and virulent storm cycles have overwhelmed water treatment plants and other key pieces of infrastructure. 

By contrast, green infrastructure is a water management approach that takes its cue from nature. Protecting upstream water sources is a form of green infrastructure investment that can help alleviate the pressure on water systems. There are almost as many ways to manage source water as there are water sources, but The Nature Conservancy’s “Urban Water Blueprint” report, which surveyed more than 2,000 watersheds, identifies five archetypes: forest protection, reforestation, agricultural best management practices, riparian restoration, and forest fuel reduction. 

For instance, in the páramos above Quito, FONAG funded work to keep cattle off the most fragile grasslands and employed guards to stop rogue burning, because rebuilding the ecosystem was a top priority. Working across nearly 2,000 square miles, the fund has now protected more than 70,000 acres of land. This effort has benefited more than 3,500 families, providing funding to support sustainable, profitable farming operations. 

“One of the beauties of the strategy is the social and economic results,” Soto says. “It’s not just tackling water regulation, it tackles climate change resiliency, biodiversity conservation, and it strengthens communities and creates gender equality. Most of the farms are led by women.” 

Quito’s model inspired a swell of other water funds, many launched by The Nature Conservancy. Like these examples, each has place-specific strategies and funding structures: 

• In 2021, the Greater Cape Town Water Fund invested $4.25 million in removing invasive plants such as gum, pine, and eucalyptus trees, which were absorbing an estimated 15 billion gallons of water each year from this drought-stricken watershed—equal to a two-month water supply. More heavily engineered solutions like desalination plants or wastewater reuse systems would have cost 10 times as much, The Nature Conservancy estimated. 
• Since the Upper Tana–Nairobi Water Fund launched in 2015, organizers have worked with tens of thousands of the watershed’s 300,000 small farms to keep sediment from running down the region’s steep slopes into the Tana River, which provides water for 95 percent of Nairobi’s 4 million residents. The effort has reduced sediment concentration by over 50 percent, increased annual water yields during the dry season by up to 15 percent, and increased agricultural yields by up to $3 million per year. In 2021, the fund became an independent, Kenyan-registered entity. 

• The chemicals used in conventional bamboo production were polluting China’s Longwu Reservoir, which provides drinking water to two villages of 3,000 people. With an initial investment of $50,000, the Longwu Water Fund has helped local farmers adopt organic and integrated farming methods, now used in 70 percent of the area’s bamboo forests; promote ecotourism; and provide environmental education programs. In 2021, the water utility and local government agreed to pay into the fund on behalf of all water users. 

Measuring Progress 

Water funds support conservation projects that address a range of issues, including sedimentation and turbidity, nutrient build-up, and aquifer recharge. They also create social and environmental cobenefits, like protecting and regenerating habitat and sequestering emissions. 

There are financial upsides as well: according to The Nature Conservancy, these investments in land management can provide more than $2 in benefits for every $1 invested over 30 years. One in six cities could recoup the costs of investing in upstream conservation through savings in annual water treatment costs alone.  

Creating a water fund requires establishing governance systems, securing funding, identifying conservation goals, and defining benchmarks for measuring progress. “The business case development is hard: how much money, where is it going to be invested,” Soto says. Part of the business case is demonstrating the ecological and financial benefit of a fund. Soto says that’s the biggest challenge, because the benefits of conservation are long term, and don’t present themselves immediately. 

“Water is difficult,” she says. “The challenge is not only time—we have to prove the case over many years—but also the aggregated result. How much of the water quality or quantity is because of the water fund?” She says FONAG struggled to find a way to quantify that, but researchers from San Francisco de Quito University helped set up a monitoring system that tracked water quality and quantity. That system has been used to mark progress and to show investors the direct benefits of this work.  

“It’s not an easy sell, especially when you’re talking about committing funding for 50 or 70 years,” Benitez says. “But now, 20 years later, we have a lot of tools to show the benefits of nature-based solutions.”  

She says that over those years, as The Nature Conservancy has introduced water funds in Colombia, Brazil, and other countries, they’ve learned to show potential partners concrete, measurable outcomes, and they’ve gathered tools and science to back up the work. 

Scaling Up 

Quito’s project has been considered a success over the years, but while building a single water fund is one thing, scaling the concept is another. As the water fund model has expanded to other countries and continents, challenges have come up. Changing the way water institutions think and operate takes time and negotiation. On the financial side, transaction and set-up costs can be high, and there’s no clear framework to compare the costs of nature-based solutions and gray infrastructure. Logistically, setting up a fund is different every time; Cape Town’s invasive species problem is different, for example, from Quito’s páramo protection needs. 

To address these challenges, The Nature Conservancy—along with the Inter-American Development Bank, the FEMSA Foundation, the Global Environment Facility, and the International Climate Initiative—formed the Latin America Water Funds Partnership in 2011. The goal of the partnership, which is described in From the Ground Up, a recently published Lincoln Institute Policy Focus Report, is to scale the development of water funds in the region and provide a global model for how to help urban centers with source water protection. 

A year after its launch, the partnership published a manual intended to provide resources that could guide work everywhere, even though each place faced specific challenges. “We have water funds that work with indigenous groups upstream, and we have other funds that have more large landowners, or small farmers,” Benitez says. “Our common purpose is to establish agreement with the groups and set up the responsibilities of the fund.”  

That’s different in every case, but there are certain elements that can help make a water fund successful, like political involvement. For instance, Soto says that in Bogotá, Medellín, and Cartagena, fund organizers made sure to involve Colombia’s Ministry of Environment and Ministry of Housing, which is in charge of graywater. “Having them on board provides a platform to facilitate policy change, so we don’t start from scratch,” she says. The Nature Conservancy also offers strategies to engage companies, and to show them how supporting water funds reduces their long-term risk. 

In 2018, The Nature Conservancy took the framework a step further, building a Water Funds Toolbox designed to guide potential partners through five stages of a project: feasibility, design, creation, operation, and consolidation. The toolbox, which leans on 20 years of accrued knowledge, shows how and where a water fund can help with water quality and availability, and provides a framework for the financial and conservation side of planning, too. 

Maine Adopts the Model

In Maine, the members of Sebago Clean Waters took that toolbox and ran with it. “From the very beginning, we strived to design Sebago Clean Waters as a replicable model for other coalitions, regions, and water funds to learn from,” said Meyer, of the Highstead Foundation. 

The coalition assessed the fund’s feasibility, commissioning a study by the University of Maine. The study found that reducing area forest cover by even 3 percent could noticeably increase pollutants. If forest cover decreased by 10 percent, it would cause the watershed to fall below federal filtration standards, the study said: “Protecting the filtration-avoidance waiver saves PWD and its customers an estimated $15 million per year in expected additional annual filtration plant costs.” 

The economic argument was strong. The researchers found that every dollar invested in forestland conservation is likely to yield between $4.80 and $8.90 in benefits, including the preservation of water quality. If a filtration plant became necessary, however, PWD would need to increase water rates by about 84 percent to offset the costs of construction. There were ecological benefits to conserving the watershed, too, like providing habitat for trout and salmon, reducing erosion, and managing floods. 

Sebago Clean Waters came up with a plan to ensure that a total of 25 percent of the watershed—35,000 acres—was conserved over the course of 15 years. They started with projects like the 1,400-acre Tiger Hill Community Forest in the town of Sebago. That tract was protected through a partnership between the Loon Echo Land Trust, a member of the coalition that has worked to protect the northern Sebago Lake region since 1987, and the Trust for Public Land. In 2021, Sebago Clean Waters announced its participation in a deal that would protect more than 12,000 acres in Oxford County, including the headwaters of the Crooked River, the lake’s main tributary. The amount of protected land in the watershed has increased from 10 percent to 15 percent.  

Land conservation isn’t cheap or easy, especially in New England, where much of the lakeside land has long been in private hands. Achieving the water fund’s goals will take an estimated $15 million. But the fund is gaining momentum: building on an initial capacity-building grant of $350,000 from the U.S Endowment for Forestry and Communities; private and corporate funding; and a commitment by the Portland Water District to provide up to 25 percent of funding for each watershed conservation project that meets its criteria, the coalition recently landed an $8 million Regional Conservation Partnership Program award from the USDA. 

Local businesses have also stepped up. In 2019, Portland’s Allagash Brewing offered to donate 10 cents from every barrel of beer it brewed, a total of about $10,000 a year. Allagash was the first of about 10 companies—including four other breweries—that have joined the coalition. MaineHealth, a statewide hospital network, just got involved as well. 

“Drinking water is so compelling, it’s not a hard sell to talk to people about protecting it—particularly the breweries, because beer is 90 percent water,” Young says. “They understand the benefit as a business and as a community member.” She’s been surprised at the reasons so many partners have come on board. Many aren’t doing it because of their bottom line; they’re concerned with sustainability, and with supporting the communities where their employees live. 

Sebago Clean Waters has accomplished a great deal, but its members are very aware of the time-sensitive need to protect this relatively pristine resource. After all, conserving land and water is easier than restoring them. Once a clean water source is gone, it’s hard to bring back. 

As the water fund model spreads, it’s illustrating the real potential of upstream-downstream partnerships to make meaningful change. This work is not simple or immediate, but it can have lasting positive impacts in watersheds and communities around the world. Meyer said the model holds great promise: “It’s powerful to see how far a trust-based partnership can go.” 

Heather Hansman is a Colorado-based journalist and the author of the book Downriver. She’s a Registered Maine Guide and a lover of the state’s rivers. 

Lead image: Sebago Lake, Maine. Credit: Phil Sunkel via iStock/Getty Images Plus. 

City dwellers around the world noted one surprisingly welcome side effect of the lockdown phase of the pandemic era: less noise. Urban soundscapes have largely returned to form, but that peaceful interlude served as a loud and clear reminder to planners and policy makers that the audible does shape city life—and can, in turn, be shaped by policies that include thoughtful land use and design. Inger Andersen, executive director of the United Nations Environment Programme, highlighted the issue in the Financial Times earlier this year, writing that “city planners should take both the health and environmental risks of noise pollution into account.”  

Of course, the underlying insight here is not new. Citizens have probably complained about various forms of city noise, from construction to concerts to rude neighbors, for as long as cities have existed. While a relatively quiet urban neighborhood might register an ambient level of about 50 decibels, higher levels can begin to interfere with conversation; a busy roadway can measure about 70 decibels (about equal to a vacuum cleaner), and a train crossing that road can push the decibel reading to 90 or higher.  

Studies documenting the health effects of noise pollution, which range from sleep disturbances to cognitive issues to heart disease, date back at least to the 1970s. The World Health Organization, along with regulators in the United States, Europe, and elsewhere, has highlighted the issue for decades, often spurred by a panoply of noise activists.  

“The good news is, there is much more interest today,” says Arline Bronzaft, a City University of New York professor emeritus who conducted some of the earliest studies documenting the impact of city noise on health and well-being. Trained as an environmental psychologist, Bronzaft continues to advocate for quieter built environments as a board member of the environmental nonprofit GrowNYC. Today, she says, there’s much more research, and an openness to policy experimentation. “Now that you’ve got the data,” she says, the question is becoming: “What are you doing about it?” 

The answer is a work in progress, but we may be at a pivotal moment for thinking about what might be termed “built soundscapes.” The tools available to assess the challenge have radically improved. And that may help planners and policy makers devise and enable better design and policy strategies to cope with the problem.  

Maybe the most prominent example involves the evolution of tools to measure sound, which have become more sophisticated and are being deployed in new ways. Recently, for example, authorities in Paris and other French cities have begun to experiment with “sound radar” devices meant to function like speed cameras: triggered by noise that exceeds code decibel limits, the sensors photograph the offending vehicle’s license plate and fine the owner.  

The French sensors were developed by Bruitparif, a state-backed agency devoted to studying city acoustics in Paris and elsewhere. Similar technology is being tested in New York, Edmonton, and other cities. Most cities already have some sort of noise ordinances in place, but such rules are rarely enforced in a systematic or consistent way. The advanced new sensors could help remedy that.  

Still, there’s an argument for going deeper in thinking about sound—using technology as a planning tool, not just a punitive one. Erica Walker, professor of epidemiology at the Brown University School of Public Health and founder of Brown’s Community Noise Lab, spent years creating the “2016 Greater Boston Noise Report,” mapping noise data she collected at some 400 locations around the city. The experience gave her a different perspective on soundscapes.  

“I started as pro-quiet,” Walker says. In fact, she explains with a laugh, she was partly interested in finding out whether city noise codes might help her get some loud neighbors to pipe down. Creating her noise report brought Walker into contact with a cross section of situations, teaching her that “neighborhoods and sound are complex.” Because ordinances focus almost exclusively on sound as a nuisance, they’re often incomplete or counterproductive, she explains. Since some level of sound is inevitable in a city, Walker says, considerations of how the acoustic environment affects residents and their interactions with each other should be built into planning and development: “Now I’m anti-quiet—but for peace.”  

Her Community Noise Lab project is focused on reworking the soundscape dialogue between citizens and policy makers; among other initiatives, that has included creating a free app called NoiseScore to make sound measurement an accessible, collaborative activity. City officials in Asheville, North Carolina, used the tool as part of their effort to incorporate more community feedback into revisions to the city’s noise code, which was updated in the summer of 2021. While that still boils down to crafting ordinances, it’s an example of technology broadening the discussion, rather than simply serving as an enforcement tool. “They didn’t start with: ‘We’re going to put these sensors up across the city and punish people if they are doing this or that,’” Walker says. “They wanted to understand all of the partners’ perspectives.” 

Tor Oiamo, a professor in the Department of Geography and Environmental Studies at Toronto Metropolitan University who conducted a recent public health noise study in that city, notes that more sophisticated sensors, mapping, and modeling software are creating opportunities to plan with sound in mind. In the years ahead, he says, the tools at hand could include a kind of global noise database similar to those tracking air pollution. But there’s an obvious challenge: “The difficulty in mitigation with a city that’s already built is that the structure is in many ways locked in,” he says.  

In some cases, cities have found ways to modify or add to existing infrastructure. Bronzaft’s groundbreaking research in the 1970s—she documented the negative impact of a New York subway traveling on an elevated line near a school—resulted in the installation of sound-muffling acoustic tiles in classrooms, and the use of rubber pads on tracks throughout the subway system to lessen train noise. Other train systems now use rubber tires, and the next wave of quiet mass-transit innovation includes maglev trains and electric buses.  

Oiamo also points to successful efforts in Amsterdam and Copenhagen to revise traffic patterns, with the specific goal of reducing noise in residential zones. And he credits Toronto with a thoughtful approach to its current Port Lands development project: because it’s reminiscent of a master-planned neighborhood, it’s possible to factor the soundscape into the design process. In addition, many of the most measurably useful ways to mitigate urban noise overlap with thoughtful land use: more green space and trees, careful consideration of building density (strategic density can actually create pockets of quiet), and so on.  

Land works have been used to mitigate urban noise for years, from the berms around the edges of New York’s Central Park to trees and sound barriers along highways. A more recent tech-forward iteration comes from German firm Naturawall, which has designed “plant walls”—galvanized steel frames with a relatively slim profile, filled with soil and sprouting a thick layer of foliage and flowers. The walls, currently in use in some German cities, are said to block sound levels roughly equivalent to typical city traffic. Other companies, including Michigan-based LiveWall, are undertaking similar projects around the world.  

None of these strategies offers a silver bullet. But Oiamo, like Bronzaft and Walker, emphasizes that at this point, there is plenty of expertise to draw upon to improve our built soundscapes. Newer technologies are helping define the issues with greater nuance and offering fresh solutions. While sensors helping issue tickets for noise violations may not represent the kind of holistic approach Walker or Bronzaft have in mind, they’re a start. As the subject gets more attention and technological options proliferate, soundscape experts are sensing the potential for real, if incremental, progress. “There’s a million things to do,” says Oiamo. That’s the challenge—and the opportunity.  

Rob Walker is a journalist covering design, technology, and other subjects. He is the author of The Art of Noticing. His newsletter is at robwalker.substack.com.  

Image: Sensors in Paris and other cities monitor and report noise levels from passing traffic. Credit: Courtesy of Bruitparif.

SINCE THE WORLD FIRST NEGOTIATED A CLIMATE TREATY in 1992, three precious decades have ticked by while we’ve allowed a climate challenge to evolve into a climate crisis. The latest assessment from the Intergovernmental Panel on Climate Change, released this spring, eschewed the moderate language of the staid scientific body, making it clear that society faces an urgent crisis and must take action. That report represents “a litany of broken climate promises,” said UN Secretary General António Guterres. “It is a file of shame, cataloguing the empty pledges that put us firmly on track toward an unlivable world.” 

At last year’s UN Climate Summit in Glasgow, the nations of the world doubled the emissions reductions they had previously promised for this decade, but we actually need a fivefold enhancement of those goals. As things stand now, we can emit only about 300 billion tons of carbon dioxide (GtCO2) before global temperatures are expected to exceed the 1.5 degrees Celsius identified in the Paris Agreement as the upper limit of acceptable warming. If countries fail to cut emissions far beyond what they’ve promised so far, the world will exceed that 300 billion tons within this decade. That will lead us toward chaos far greater than the unparalleled storms, droughts, wildfires, and displacements the globe is already experiencing. 

It’s well within our capabilities to dramatically cut emissions. We know which renewable energy technologies and energy-efficient practices we need to deploy widely, we know that protecting ecosystems and other species supports our own ability to thrive, and we’re equally aware of the exceedingly wasteful and fossil fuel–intensive agricultural practices and land-intensive diets that we need to alter. 

As it turns out, land figures prominently in many of our most promising climate solutions, and is thus central to many of the tensions and trade-offs we must now deftly navigate. Having pushed the clock to the limit, we must find a way to avoid moving forward haphazardly, running roughshod over fundamental ecological and human needs in a mad dash for “climate-friendly” solutions. Stewarding land wisely while we face an increasingly hostile climate will prove critical to securing a livable future. 

EVEN WHILE LAND IS INCREASINGLY STRESSED BY A CHANGING CLIMATE, it will face rising and conflicting demands from human society in our pursuit of both climate solutions and sanctuary from a more hostile climate. Let’s lay out the main aspects of this contested landscape. 

Land will be required to sustain species and ecosystems that are increasingly threatened by climate change to the point of extinction or collapse. Earth is currently undergoing its sixth mass extinction since the Cambrian explosion half a billion years ago. Writing of the evolutionary tree of life, Elizabeth Kolbert, a scholar of such extinctions, explains: “During a mass extinction, vast swathes of the tree are cut short, as if attacked by crazed, axe-wielding madmen” (Kolbert 2014). Even as a metaphor, this may be an understatement, as we now also have bulldozers, big dams, and other even less judicious means of directly appropriating land from natural ecosystems. 

As human-caused climate change accelerates, it will overtake our appropriation of land as the top driver of the ongoing extinction (IPCC WGII 2022). A report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services found that more than a million species are threatened with extinction, many in the next few decades (IPBES 2019). Sustaining the natural ecosystems on which human survival depends—from the mountainous snowpack from which rivers run year-round to the rich soils in which our food grows to the coral reefs that sustain coastal fisheries—ultimately will rest on our ability to reduce and reverse our appropriation and fragmentation of natural habitat, all while we stop fueling climate change. 

As a critical first step, nearly 100 countries comprising the High Ambition Coalition for Nature and People have called for a global 30×30 deal to protect 30 percent of the world’s land and oceans by 2030. This ambitious effort aims to halt biodiversity loss and preserve ecosystems, with the added benefits of supporting economic security and a stable climate. Today, only about 15 percent of our land and 7 percent of our oceans is protected. 

Land will be required to resettle people displaced by flooding, extreme weather, and climatic shifts that render currently inhabited areas no longer hospitable. We know the climate and weather extremes that are already driving displacement will escalate. The World Bank estimates that more than 200 million people will be forced from their homes by climate change in Asia, Africa, and Latin America in the next few decades, and millions more will be affected in other regions. This climate-induced dislocation and involuntary migration will amplify existing stressors such as conflict, food and water insecurity, poverty, and loss of livelihoods from economic or environmental pressures (IPCC WGII 2022). 

In other words, marginalized and disempowered households and communities will invariably suffer the worst consequences, which will with rising frequency rise to the level of humanitarian and human rights crises. Any effort to manage these situations humanely will have implications for human settlements and the habitable land that they require. Resettlement will require far less land than other demands—one estimate suggests 0.14 percent of the planet (somewhat less than the area of the United Kingdom) could absorb 250 million climate migrants (Leckie 2013). Yet the mass climate migration already underway represents a significant shift in how and where people occupy and use land, and should be a priority for efforts to secure and preserve human rights for migrants and refugees. 

Land will be required to feed our expanding global population, even as some regions face declines in water, increases in pests, and diminishing soil fertility. Climate change has slowed the growth in food productivity that was seen over the last decade, and climate-related extreme events have exposed millions of people to acute food insecurity and undermined water security. 

A worsening climate will heighten these threats—which are, once again, cruelly directed at those who are marginalized and disempowered. Agriculture constitutes the primary human pressure on the global landscape; estimates suggest that it has already led to the clearing or conversion of 70 percent of global grassland, 50 percent of savanna, 45 percent of the temperate deciduous forest, and 27 percent of tropical forests. Agriculture also affects water bodies through drainage and chemical runoff, and emits greenhouse gases and pollutants into the atmosphere. 

Agricultural approaches founded on principles of biodiversity and ecosystem regeneration are being increasingly proven and scaled, and have the potential to help combat climate change, even with a growing global population. Likewise, major changes to our global food system that prioritize human rights, and that reduce meat consumption and food waste, can dramatically expand and deepen food security. A staggering share of global plant crops is eaten by livestock rather than people. More than one-third of all calories and more than one-half of all protein from agricultural crops goes to feed animals, with only a small share ultimately becoming nourishment for people. The consumption of meat is specifically charged with causing the continuing spike in deforestation of the Amazon rainforest, a biome that comprises 40 percent of the world’s rainforest and serves as home to 25 percent of its remaining terrestrial species. 

Land will be called on as a site for the energy sources—primarily solar power, wind power, and biopower—needed to replace the fossil fuels that now meet five-sixths of global energy demand. Solar and wind power, while they have undeniable impacts on the landscape, can be situated in areas suited for multiple uses; for example, wind turbines and solar panels can be sited on farmland or in urban spaces like rooftops and parking lots. Unlike solar and wind power, bioenergy—which is produced using agricultural feedstocks, in the form of either electricity (biopower) or fuels (biofuels)—must be sited on agriculturally productive land. At any significant scale, bioenergy competes with food production. 

Consider the following: total cropland globally amounts to less than half an acre per person, yet it already puts considerable pressure on water, soil, and other ecological resources. Even if we posit a quite efficient process for producing and using biofuel (in contrast to the U.S. approach of burning corn-based ethanol in conventional combustion vehicles), more than 1.2 acres would be needed to keep a single passenger vehicle fueled. An efficient biopower plant would fare hardly any better, claiming roughly 0.8 acre per capita to grow the fuel needed to generate the electricity used by the average United States resident. By contrast, solar photovoltaics require less than 5 percent of one acre per person or, for the whole U.S. population, a bit less than 15 million acres. This is not a trivial footprint, but it’s worth noting that in 2017 alone, federal land leases offered for oil and gas production in the United States amounted to more than 12 million acres. 

To put it plainly, bioenergy would function for the typical high-energy consumer just as meat functions for the typical high-meat consumer—it would allow them to consume vastly more land than they would if they simply used that land’s output directly. By extension, it would also enable the world’s over-consumers to compete even more ruthlessly with the world’s poor for the resources that underpin survival, like food, livelihoods, and homes. 

Land will be called upon to “negate” our carbon excesses by removing accumulated carbon dioxide from the atmosphere. The world’s lands serve as an enormous carbon sink, with plants and soil absorbing about a quarter of our excess carbon dioxide from the atmosphere. (Another quarter of our excess carbon emissions is absorbed by the oceans; the remaining one-half accumulates in the atmosphere and is responsible for warming the planet.) Deterioration of an ecosystem—such as by climate-induced pests, drought, fire, and deliberate human modification—diminishes its capacity to absorb carbon, and may even convert it into a source of carbon dioxide emissions. Unchecked climate change could disrupt climatic conditions enough to send a region like the Amazon rainforest across such a tipping point—converting it from a carbon sink to a carbon source—and in fact, just such a weakening of resilience is already being observed there (Boulton, Lenton, and Boers 2022). 

Despite the threats that climate change poses to natural carbon absorption, it is increasingly held out as an alternative to reducing our own emissions, or at least as a crafty expedient whereby we can buy some time, relax the mitigation burden a bit, and more gradually ramp up our emissions reduction efforts over a longer timeframe. Indeed, the hopes for these “negative emissions” strategies have grown beyond reasonable expectations. 

Some analysts of future mitigation options assume the removal of carbon dioxide from the atmosphere and storage of it on the land (in the form of plant or soil matter) or underground (as compressed carbon dioxide transported in pipelines) will grow to a scale comparable in land requirements to current global agriculture. 

If we cooperated globally and worked strenuously to keep emissions within the 1.5-degree Celsius budget, viewing negative emissions as a possible solution for situations that were virtually impossible to address any other way (such as methane emissions from wetland rice cultivation) would be feasible and sensible. But instead, most countries have charted a slow pace of reduction efforts for the near term and inadequate reduction targets for the medium term; they have labeled these steps consistent with the Paris goals, presupposing a vast reserve of land will wondrously materialize for negative emissions duty when we need it. This is a reckless strategy. Pursuing it further means banking on land being available and hoping that negative emissions activities won’t conflict with social needs such as food security.  

Because the world has willfully downplayed the near-term effort needed to keep climate change within manageable bounds, such a strategy could leave us—and future generations—stranded with an insufficiently transformed energy economy. Saddled with a fossil fuel–dependent energy infrastructure, society would face a much more abrupt and disruptive transition than the one it had sought to avoid. Having exceeded its available carbon budget, it would face a carbon debt that cannot be repaid, and ultimately see much greater warming than it had prepared for. 

WISE LAND USE AND STEWARDSHIP WILL PROVE CRITICAL to navigating our future. The specific technologies, practices, and policies are enormously varied and context specific, so it would be foolish to attempt a fair treatment here. But a few broad observations are warranted. 

First, several cases touched on above illustrate how society is increasingly relying on land resources to help deal with climate change, even while land is itself under rising stresses from climate change. The expected tensions and trade-offs are already testing society’s capacity for wise land stewardship in a more hostile climate, with mixed results. 

As biodiversity loss accelerates, there is increasing recognition that a large share of remaining biodiversity-rich areas—including more than one-third of intact forests and 80 percent of the world’s terrestrial biodiversity—is in the hands of indigenous groups. These stewards have protected both biodiversity and forest carbon more successfully than others, even during decades of rapacious extraction of global forest resources (Fa et al. 2020; World Bank 2019). This understanding must now be translated into policies that legally recognize and actively enforce community-based land tenure rights consistent with the UN Declaration on the Rights of Indigenous People, which most indigenous communities do not yet enjoy. Where that is done, indigenous communities will be better able to protect common resources through locally appropriate collective action. They will also be better able to resist outside actors who are intent on either extracting and degrading forest resources or on imposing “fortress conservation” models that disregard indigenous rights and are less effective in their ostensible conservation aims. 

Much the same lesson applies to a range of emerging “green grab” strategies. As pressure on land is intensified by growing demand for bioenergy and food production, negative emissions capacity, and habitable areas, those who have capital, flexibility, political savvy, and powerful networks are crafting the relevant policies and ultimately benefiting from them, including through speculation. Consequently, the cost of public efforts to meet collective needs escalates, preventing people with the least political or economic power from meeting basic needs like food, livelihood, and home. New ways of abstracting these components of land and ecosystems and integrating them into distantly removed market processes are legitimizing new forms of appropriation. Some of them are akin to financial derivatives, and indeed can be disconcertingly reminiscent of the mortgage-backed financial derivatives, the collapse of which brought on a global recession and threatened much worse. One particularly glaring example is the carbon offset program (the Clean Development Mechanism) that developed countries have used to meet their legally binding targets under the Kyoto Protocol. This mechanism is now understood to have been based overwhelmingly on fictitious greenhouse gas reductions. 

We should thus be wary about market mechanisms that simply carry forward questionable assumptions of equivalence (among distinct bits of natural capital) or of fungibility (between natural resources and technical alternatives), and about policy regimes that privilege the idea of net economic welfare to rationalize probable casualties of distribution or outright injuries to human rights and justice. 

AS SPECIFIC CHARACTERISTICS OF LAND and ecosystems—such as their promise as a carbon sink or suitability for energy production—become more highly valued and more tightly integrated into the global economy, a fundamental question becomes only more pressing: who controls land and who benefits from it? 

Lincoln Institute President George McCarthy put it succinctly at the organization’s Journalists Forum on climate change this spring: “Land contention redounds to power. And in disputes, power wins.” If the very power structures at the root of climate change are left intact, then the resulting market mechanisms and policy interventions will fail to save the climate while worsening the global scourge of poverty and marginalization. In doing so, they can contribute to what is becoming the third injustice of climate change: the most vulnerable are not only the least responsible for and most affected by climate change, but also the frontline victims of ill-conceived climate policies. 

Our global society is confronting risks of an existential magnitude. These risks—all of our own making—are equal parts ecological and social. Ecologically, we persist in placing insupportable burdens on our planet. Socially, we remain riven by obscene disparities in wealth and power that have rendered us dysfunctional in the face of a civilizational threat. Solutions do exist. The importance of shifting to a less meat-intensive global diet for reasons of environmental sustainability—as well as personal health—is now clear. We have learned to be wary of narrowly focused mechanisms like carbon markets for protecting forests, given how complex these ecosystems are and how they provide multiple services to diverse human societies, not all of which are monetizable or even fully understood and appreciated. 

Experience has shown us that indigenous communities, especially once they have legally enforced tenure rights, do a highly effective job managing forests and protecting biodiversity. On already significantly altered or degraded land, innovations in regenerative agriculture and ecosystem restoration are providing a means to maintain or enhance land-based carbon. And technological advances in the energy sector have made it possible for us to rehabilitate our fossil fuel–addicted global economy. 

Perhaps most important, the world has finally reached a level of aggregate global welfare that—if it were shared more equitably—would make possible a dignified life for all, free from the privations of underdevelopment. We have the tools to save ourselves, but it remains up to us to actually do so. 

Sivan Kartha is a senior scientist at the Stockholm Environment Institute and codirector of its Equitable Transitions Program. He served on the Intergovernmental Panel on Climate Change during the preparation of its Fifth and Sixth Assessment Reports, and serves as an advisor to the Lincoln Institute climate program.  

Lead image: Amazon rainforest, Brazil. Credit: Gustavo Frazao via iStock/Getty Images Plus.

REFERENCES 

Boulton, Chris A., Timothy M. Lenton, and Niklas Boers. 2022. “Pronounced Loss of Amazon Rainforest Resilience Since the Early 2000s.” Nature Climate Change 12 (271–278). March 7. 

Fa, Julia E., and James EM Watson, Ian Leiper, Peter Potapov, Tom D. Evans, Neil D. Burgess, Zsolt Molnár, Álvaro Fernández-Llamazares, Tom Duncan, Stephanie Wang, Beau J. Austin, Harry Jonas, Cathy J. Robinson, Pernilla Malmer, Kerstin K. Zander, Micha V. Jackson, Erle Ellis, Eduardo S. Brondizio, Stephen T. Garnett. 2020. “Importance of Indigenous Peoples’ Lands for the Conservation of Intact Forest Landscapes.” Frontiers in Ecology and the Environment 18(3): 135–140. 

IPBES. 2019. “Global Assessment Report on Biodiversity and Ecosystem Services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.” E. S. Brondizio, J. Settele, S. Díaz, and H. T. Ngo (eds.). Bonn, Germany: IPBES Secretariat. 

IPCC WGII. 2022. “Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change.” H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.). Cambridge, UK, and New York, NY: Cambridge University Press. 

Kolbert, Elizabeth. 2014. The Sixth Extinction: An Unnatural History. New York, NY: Macmillan.  

Leckie, Scott. 2013. “Finding Land Solutions to Climate Displacement: A Challenge Like Few Others.” Geneva, Switzerland: Displacement Solutions. 

World Bank. 2019. “Securing Forest Tenure Rights for Rural Development: An Analytical Framework.” Program on Forests (PROFOR). Washington, DC: World Bank.