Ben Christensen &Marisa Repka

District of Columbia (Operating nationwide)

Project Overview

Each year 36 million trees fall in American cities. The vast majority are mulched, landfilled, or burned—at eye-popping economic and environmental cost. At the same time, cities struggle to equitably reforest neighborhoods, with communities of color long burdened by unequal access to benefits that urban trees provide. Connecting these two challenges, Cambium Carbon leverages the urban tree life cycle, showing that by processing—rather than discarding—downed urban trees, we can create a waste-to-value revenue stream that returns needed funds to replant low-canopy neighborhoods. In this circular economy model, green jobs are created through urban “Reforestation Hubs” that could upcycle an estimated 46 million tons of merchantable wood every year into products such as lumber, bioenergy, and compost. Building the infrastructure to upcycle such wood into high-value durable goods creates an opportunity to engage residents who face barriers to traditional employment, while providing training in technical skills across the tree life cycle. Meanwhile, using salvaged wood displaces emissions-intense global supply chains. And by investing in tree planting among underresourced communities, Cambium Carbon can catalyze carbon sequestration, stormwater management, air pollution mitigation, and energy savings in places that need them most.

Five Questions

1What needs does your project address and how?

Cambium Carbon is building Reforestation Hubs as a sustainable model for equitable urban forest restoration. Trees are precious assets for human and environmental health, yet as a country we haven’t invested in those assets equally. Within the U.S., affluent communities have as much as 65% more tree canopy than their lower-income counterparts. Cambium Carbon works to take the 46 million tons of salvageable wood that falls in U.S. cities each year, and divert that material from the waste stream, instead creating products that reinvest in new tree planting. By creating a new source of revenue to support underresourced communities, we’re creating a regenerative circular economy that can restore critical urban canopy.

2Tell us about a moment that helped inspire your idea.

While working on federal climate policy at the World Resources Institute, Ben was fortunate enough to get a firsthand look at the kind of investment that will enter the climate space in the coming years from companies, the finance sector, and government. He was struck by the lack of scalable grassroots projects available. There was a giant gap between supporting communities with the grace and specificity required to build effective local solutions, and the ability to translate and scale those solutions into national climate initiatives. Recognizing that, we set out to build a platform to facilitate people-first climate solutions by transcending scale.

3What is the biggest challenge you face right now?

We’re building a two-sided marketplace for a salvaged waste material; as a result, we have to grow both the supply of and demand for urban wood. We need to increase the investment in new and existing infrastructure, while also scaling demand for this high-impact material. Supply constraints are not a limiting factor yet, but they will be soon.

4What other leaders have informed your work?

The U.S. Forest Service and the Baltimore Wood Project have been critical in pioneering a model for urban wood salvage and reuse.

5Describe a participant, client, community member, or someone else who represents what your project is all about.

The beauty of this project is that it has huge potential for diverse community impacts: from residents who benefit from urban cooling and air quality improvements, to individuals seeking job training in tree care or carpentry. But specifically, it’s about equitable restoration of our urban canopies, and providing a sustainable model for investing in underserved communities.

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