As a designer in the U.S. working to decarbonize my small part of the design and construction industry, 2025 has been a gut punch. Spending time reviewing Environmental Product Declarations or searching for the best locally available low-carbon concrete mix can feel like tiny contributions when federal policy shifts so dramatically. It’s not just demoralizing, but paralyzing. As a self-identifying moderate, it took me a while to realize this isn’t a conservative realignment—it’s a radical change embracing a “pro-emissions” agenda.
At the same time, in the places where I work across the country, in both red and blue communities, I find shared values. My clients all believe that we have a responsibility to deliver a clean and healthy environment for future generations. I’ve yet to meet a community member who doesn’t think designers and contractors should be less considerate of the health, safety, and welfare of future users.
As a landscape architect, I have the privilege of helping to create parks and supporting living systems and urban ecologies. Bolstering native species, protecting sensitive habitats, and celebrating the heritage of our landscapes is apolitical. When we leave the news cycle behind, most Americans still believe in personal responsibility, value our natural heritage, and support Aldo Leopold’s “Land Ethic” (even if they would never phrase it that way).
So where does this leave us? Given the immensity of the challenge, we still need government to enable change at a scale that can begin to address the economic drivers of emissions and climate change. Market forces alone are insufficient beyond jewel-box projects. Decarbonizing our economy is still beholden to the “tragedy of the commons” behavior that Garrett Hardin wrote about so many years ago: if there’s no cost directly associated with environmental damage and emissions, there’s no motivation to change.
With the abdication of federal climate leadership, we must now put our hope in our city and state governments. Over our long history, from the public works of ancient Athens to Bazalgette’s sewers, the city scale is where we find the intersection of political will, the authority to regulate, and the ability to make significant change comparatively quickly.
We’re already seeing this in response to climate change. In 2019, New York City passed Local Law 97, also known as the Climate Mobilization Act, which established the legal framework for decarbonizing building operations by 2050. In 2023, Boston adopted the first “net-zero zoning” policy in the country, which targets net-zero operational emissions (emissions associated with the use of the facility, such as electricity and heat) for all new buildings. In 2022, Toronto became the first North American city to regulate embodied carbon (the carbon required to construct a new building). Climate policies and plans are being rolled out in cities around the world, including Vancouver, Los Angeles, London, Singapore, São Paulo, and Cape Town, among others. Considering that the built environment, including operations and embodied carbon, accounts for about half of global annual emissions, decarbonizing city construction and operations is equally important as decarbonizing transportation systems, agricultural systems, and consumer consumption patterns.
In light of the political events of 2025, how can city leaders step up to fill the void in climate leadership? Perhaps they can try to manage their “carbonsheds” with the same attention and rigor as their watersheds. In the natural resources world, the term carbonsheds has gained traction to broadly describe the localized concentrations, emissions, and storage of carbon in the atmosphere and in the living environment. Studies ranging from understanding fuel stocks for potential forest fires to mapping heavy-emitting industries, mapping hydric soils, or understanding plumes of emissions from thawing permafrost have all employed this term, linking atmospheric carbon or emissions potential to geographic locality.
It’s time to broaden the definition of carbonsheds to include the carbon metabolism of a city, from emissions for energy and materials to the emissions associated with our waste cycles.
The design and construction industry has become adept at designing net-zero operational carbon facilities and, for the last decade, has developed increasing sophistication in documenting and reducing the embodied carbon of the built environment. However, for the foreseeable future, until the economy radically decarbonizes every aspect of industry and transportation, our cities will continue to emit carbon. Coordinated carbonshed policies could close that loop.
Even in a future with 100% renewable energy, the embodied carbon associated with the construction of our buildings and infrastructure will still be substantial. Architecture 2030 has estimated that approximately half of the total lifecycle emissions of a new building are in the embodied carbon to construct the facility. This ratio is increased to 75%–90% for the constructed landscape—the streets, parks, plazas, and open spaces of our cities and communities. While we study reducing our embodied carbon for construction in parallel with targeting net-zero operational carbon, cities are still adding emissions. Some cities are starting to address this with investments in urban forestry and green spaces. Still, the ratio of space needed for living systems to offset buildings’ embodied emissions is often significant.
Cities, companies, and individuals must actively contribute to drawing carbon down from the atmosphere to balance their emissions. This need has inspired the global voluntary carbon market, where tradable carbon credits are sold as virtual commodities certifying action, from reforestation to burning off excess methane. This unregulated market has experienced extreme swings in confidence, with investor enthusiasm often outpacing capacity or verifiability. Today, there’s a huge range of potential strategies and associated premiums. On one end of the spectrum, the premium carbon credits have clear “additionality,” reducing the amount of carbon in the atmosphere, and “high durability,” meaning the carbon is unlikely to be emitted again. Most of these premium credits require significant technological installations, such as the recently opened facilities in Iceland. These extraction-technology-based methods are, for now, economically difficult to scale to match the low cost of fossil fuels.
On the other end of the spectrum, credits with low additionality and durability are cheap, such as credits that “do less harm,” reducing emissions that would otherwise be emitted due to lax environmental regulations, or credits that may be unverified. In recent years, the low end of the spectrum has become rife with allegations of fraud and projects that fail to reach implementation. In 2024, the GRAIN nonprofit and the University of Chicago Data Science Institute found numerous examples where carbon credit programs in Africa were reported to dispossess existing communities and farmers from lands that had been cultivated or pasture lands previously defined or even titled as community commons.
Between these extremes are the verifiable natural systems credits: investments in reforestation, wetland restoration, and improved soil management regimes. These natural systems credits vary broadly in program design, ecological management, and legal frameworks. Some simply focus on protecting existing resources, such as the Family Forest Credits Program, which serves as a revenue tool to support small-scale conservation easements. Some support mass planting of trees to support reforestation, either in support of future timber industry (such as many Verra-certified Gold Standard Forestry Credits), or in support of long-term restoration ecology goals, such as credits created by Saving Nature.
Each of these systems relies on tracts of land and is only as effective as the institutions and policies created to protect the living systems for the time period of the protections. To paraphrase the ecologist Stuart Pimm, “Trees have been sequestering carbon for a very long time, and they are very good at it.” In the right environment, trees are self-sufficient, self-repairing, and self-replicating—a perfect low-cost technology. With increasingly powerful remote satellite mapping, multispectral lidar mapping, and machine learning, we are poised to dramatically increase our understanding of carbon stocks and fluxes, enabling us to better identify areas where we can and should invest in carbon sequestering land uses.
Through carbonshed programs, geographic proximity could help overcome the uncertainty of carbon markets, enabling more confident investment in protecting these living systems. When companies and individuals export their carbon footprints through credits, the potential risks of reversibility and fraud are compounded by anonymity. Geographic proximity could support developing personal relationships between carbon credit implementers and investors, providing accountability through shared legal and regulatory frameworks. Carbonsheds could be defined by the adjacent hinterlands and seascapes for municipalities. Investments in carbon sequestration could be made in those surrounding regions through reforestation, improved soil management, and even direct capture technologies. The carbon metabolism of the city—the net transportation, operational, and embodied carbon emissions—could be balanced by monetary investments to enable carbon drawdown in these landscapes.
Local policy could also allow for the potential for planning for social and environmental co-benefits uniquely tailored to regional needs. Carbonsheds could be a regional economic pump to support rural communities and perhaps start to mend the trends of rural disinvestment and extractive economics that have plagued urban-to-rural relationships over the last half-century. This could also mitigate the risks associated with “exporting responsibility” through international carbon credits, which may inadvertently contribute to displacement or other unintended consequences.
In Boston, the investment in water infrastructure happened at a time of rapid urbanization, and while the development of the Quabbin Reservoir included significant forced relocations, it also enabled the city to expand with a sustainable and reliable source of potable water. Future carbonshed policies will be able to build on lessons from those land acquisitions, the watershed protection measures, the infrastructure corridors, and the intricate and complex network of associated infrastructure that is now taken for granted. In some ways, carbonsheds may prove more straightforward to implement since carbon-sequestering land uses do not have to be contiguous; there should be no need for eminent domain or forced relocation. No coercion would be needed for regional carbon credit programs, just a verifiable, regulated marketplace.
Boston’s new net-zero zoning policy is complex, thoughtful, and experimental. The impacts and refinements of this policy will take years of work as the city and state work in parallel to decarbonize power plants and transportation systems. Boston is starting to study embodied carbon and encouraging voluntary reporting. While the work of delivering on net-zero operation and embodied carbon in new development continues, an intermediate carbonshed policy framework could accelerate achieving a “net climate-neutral future.” Following a simplified policy creation process, a city’s carbonshed program might follow these steps:
Phase 1—Carbonshed Questions: How could your city close the loop on your local carbon emissions? What’s the potential for carbon offsets in your region? Who do you need to ask in your government and community groups to inspire an investigation?
Phase 2—Exploration & Goal Setting: Investigating underutilized regional potential carbon sinks could identify areas where carbon sequestering programs can be effectively deployed, such as vacant lands, deforested areas, brownfields, and carbon-intensive agriculture. Investigations into monetary policy tools that could create regional marketplaces. Investigations into emissions tracking technologies for the municipalities. Prototype policies through voluntary programs. Determine carbonshed goals and timelines, scale support regions to account for realistic investment opportunities for carbon sequestration investments.
Phase 3—Encouragement: Reward reporting on operational and embodied carbon emissions. Build databases with sufficient detail to understand benchmarks for business-as-usual and targeted feasible reductions. Develop financial and process rewards for low-carbon development and investment in regional carbon offsets. In parallel, define means and methods for standard reporting and carbon accounting, both on the emissions and offsets sides of the cycle.
Phase 4–Enforcement: Establish required carbon thresholds for construction typologies, penalize non-compliant emitters, and invest penalties into sufficient offsets. Reward projects that go beyond the required thresholds. As markets and technologies evolve, adjust the thresholds to align with the most feasible best practices. Once markets and accounting are well established, incrementally scale offsets and thresholds till a net carbon-neutral system is achieved. Develop required mitigation programs with prioritization for on-site investments and a verifiable market for regional off-site mitigation investments.
Phase 5—New Questions: Assess efficacy, reversibility, and additionality. Study impacts on the cost of living, ripple effects on local economies, goods distribution, and ecology. Innovate, adapt, and refine.
By taking responsibility for the carbon impacts of our cities and investing in natural areas through carbonshed policies, our cities and regions could lead the planet’s decarbonization efforts and serve as models for scaling up global solutions. Carbonshed policies will have limitations—the process of these policies cannot happen immediately—but it would be dramatically faster than the pace of international or national agreements and regulations. Carbonsheds will not be a permanent solution for addressing emissions in cities. Most ecosystems and agricultural systems have a carbon-carrying capacity (an upper limit of accumulated biomass and soil organic carbon). However, centuries of development, industrialized agriculture, and deforestation have reduced the carbon stocks of lands near urban centers. Regardless, carbonsheds could be an essential stopgap in the fight against climate change. At the same time, the challenging work of universal decarbonization and advancing carbon direct capture technologies continues. Carbonsheds could give cities and local communities the agency to address climate change now, rather than waiting to see if the federal government ever resumes its fight against climate change.
Featured image via Recraft (V3). All other images courtesy of Sasaki.
