Most Read DIRT Posts of 2024

Lower Neches Wildlife Management Area, Galveston, Texas / Sean Burkholder, ASLA, University of Pennsylvania and with Dredge Research Collaborative

Before looking ahead to what’s happening in landscape architecture in 2025, we also look back to learn what was of greatest interest to readers over the past year.

The most-read story of the year was the U.S. Army Corps of Engineers’ new embrace of nature-based solutions. Readers wanted to know what this transformational shift will mean for future infrastructure projects.

Like in past years, readers also wanted to know how to reduce the carbon footprint of landscape architecture projects and move towards more responsible forms of design. This is about using less and choosing local, low-carbon materials.

2024 showed the real potential of designing for climate and biodiversity in cities. An exciting linear park in California proved that many kinds of materials can be reused in a beautiful way at low cost. And a constructed wetland in Baltimore’s inner harbor demonstrated how to create a tourist mecca while yielding real benefits for wildlife.

ASLA members: Have an op-ed you would like to write? Send us your idea at climate@asla.org.

In a Seismic Shift, U.S. Army Corps of Engineers Elevates Nature-based Solutions

“In a new memo, the U.S. Army Corps of Engineers announced it will expand the use of nature-based solutions in its civil works projects. Now, when the Army Corps provides a final set of planning options — what they call ‘alternatives’ — to communities, those alternatives must include ‘a fully nature-based solution alternative’ if feasible. And that alternative needs to use the ‘same level of rigor and detail as the other solutions proposed.'”

New Linear Park Shows the Great Potential of Material Reuse

“A new landscape in Hayward, California demonstrates how to reuse materials on a grand scale to save money and reduce climate impacts. Designed by landscape architects at Surfacedesign, the Mission Boulevard Linear Park — a mile-long park and walking and biking trail — repurposed asphalt, concrete, trees, soil, and even benches.”

Climate Action Is About Choosing Local, Low-Carbon Materials

“Embodied carbon accounts for 75 to 95 percent of the greenhouse gas emissions from landscape architecture projects,” said Chris Hardy, ASLA, PLA, senior associate at Sasaki, during the third in a series of webinars organized by the ASLA Biodiversity and Climate Action Committee. But by selecting locally made low-carbon materials, landscape architects can significantly reduce the climate impacts of their work.”

The Future of Landscape Architecture

“‘When Frederick Law Olmsted was practicing, he was working at the scale of the city. Today, landscape architects face challenges on a global scale — carbon emissions, land fragmentation, and extraction,’ said Kate Orff, FASLA, founder of SCAPE, an urban design and landscape architecture practice.”

Landscape Architecture Strategies Reduce Impacts of Dangerous Extreme Heat

“‘Extreme heat is expected to impact more people and places in the U.S. and across the globe in coming decades, with the greatest impacts to marginalized and underserved communities. An estimated 250,000 excess deaths are expected per year by 2050. Our research demonstrates the importance of maximizing the benefits of nature-based solutions to extreme heat. And landscape architects do that every day through their critically important planning and design work,’ Dr. Hirschfeld said.”

Landscape Architecture Strategies Reduce Biodiversity Loss

“‘The biodiversity crisis is on par with the climate crisis. An estimated one million out of eight million species on the planet are threatened with extinction. Our research demonstrates that landscape architects play a significant role in designing and preserving green spaces that enhance and restore biodiversity and promote human well-being,’ Dr. Park said.”

Landscape Architects Take on Embodied Carbon

“‘Landscape architects have started conversations about embodied carbon. There is a realization that we can no longer ignore the grey parts,’ said Stephanie Carlisle, Senior Researcher, Carbon Leadership Forum and the University of Washington.”

How Landscape Architects Are Decarbonizing Design

“‘Decarbonization has design value. It’s part of the design process, not a separate thing,’ said Marieke Lacasse, FASLA, principal at GGLO, during the second in a series of webinars organized by the ASLA Biodiversity and Climate Action Committee.”

New Guides for Landscape Architects Offer Practical Steps to Achieve Zero Emissions by 2040

“ASLA releases three new resources that cover how to decarbonize landscape architecture project specifications, the design process, and navigate environmental product data.”

Floating Wetlands Bring Nature Back to Baltimore’s Inner Harbor

“The National Aquarium’s new Harbor Wetland shows the great potential of creating wildlife habitat in cities. With just 10,000 square feet, it has already drawn otters, herons, ducks, crabs, fish, eels, and jellyfish.”

Call for Presentations: ASLA 2025 Conference on Landscape Architecture

ASLA 2025 Conference Call for Presentations / ASLA

By Katie Riddle

ASLA is currently accepting proposals for the 2025 Conference on Landscape Architecture in New Orleans, October 10 -13, 2025. Help us shape the education program by submitting a proposal through our online system by Monday, February 18, 2022, at 6 pm EST.

This year’s theme, “Beyond Boundaries,” celebrates how landscape architects are breaking down barriers—whether physical, political, or cultural—to create innovative solutions for today.

The ASLA Conference on Landscape Architecture is the largest gathering of landscape architects and allied professionals in the world—all coming together to learn, celebrate, build relationships, and strengthen the bonds of our incredibly varied professional community.

Educational Tracks

  • Biodiversity
  • Changing the Culture in Practice
  • Climate Action
  • Design and the Creative Process
  • Design Implementation
  • Equity and Inclusion
  • Learning to Lead and Grow in Your Career
  • The Future of the Public Realm

Session Formats

  • 60-, 75-, or 90-Minute Education Sessions: The standard education session. Each session includes a 60-minute presentation followed by a 15-minute Q&A, featuring two or three speakers.
  • Field Sessions: Field sessions combine educational content delivered by multiple speakers with an immersive field experience. Field sessions are organized through the host chapter. Please email asla2025fieldsessions@gmail.com if you’re interested in submitting a field session.
  • Deep Dive Sessions: These are by invitation only. If you have an idea you wish the Annual Conference Education Advisory Committee to consider, please email us at speaker@asla.org.

If you’re an ASLA member, make sure you have your unique ASLA Member ID or username handy – you should use it to log into the submission system. Non-members, including allies from the fields of urban planning and design, architecture, natural and social sciences, and public art, are also most welcome to submit proposals.

Please visit the submission site to learn more about the 2025 education tracks, submission criteria, review process, and key dates.

Submit your session proposal today.

Katie Riddle, ASLA, is managing director of programs at ASLA.

Designing with Biodiversity (Part I)

Fernhill South Wetlands Natural Treatment System, Forest Grove, Oregon. Three years after completion and re-vegetation with native species. / copyright Jim Maloney, courtesy of Biohabitats

“Biodiversity is a simple word to describe the complex sum of all life on Earth,” said Keith Bowers, FASLA, president of Biohabitats, in a recent online discussion. “Biodiversity happens at the species, genetic, behavior, and ecosystem levels.”

In some respects, the biodiversity crisis is a greater threat than the climate crisis. With dramatic reductions in emissions and increased carbon drawdown, we can reverse climate change and cool the planet, undoing or avoiding a lot of damage. “But once you lose species, they are gone forever.”

Bowers sees five primary causes of biodiversity loss, in descending order of importance:

5) Climate change
4) Pollution, including air, water, and nitrogen pollution
3) Overexploitation of natural resources
2) Invasive species
1) Habitat loss and fragmentation

Landscape architects are designing with biodiversity for the sake of tree, plant, insect, bird, and other species around the world. But creating healthy habitats for species also provides so many other benefits: improved water management, air and water quality, health and well-being, livelihoods, and climate resilience.

Given the significant drop in insect, bird, and other important wildlife populations worldwide, it’s important to scale up efforts to achieve 30 x 30, Bowers said. This is the global campaign to protect and restore 30 percent of the world’s terrestrial, coastal, and marine ecosystems by 2030.

To give a sense of the scale of the challenge: “only 12 percent of the U.S. is now protected. We need to at least double that in the next five years.”

Landscape architects can help with this national and global effort. “We can play a leadership role” in protecting and reconnecting landscapes. “Nature is in trouble. We can have a major impact by restoring the Earth.”

30 x 30 will happen project by project. How landscapes are designed results in either biodiversity loss or gain, explained Dr. Sohyun Park, ASLA, associate professor at the University of Connecticut and author of the ASLA Fund research study Landscape Architecture Solutions to Biodiversity Loss.

“We can design landscapes to actively protect biodiversity. We need to shift our mindsets to intentionally include biodiversity and go beyond people-centered design.”

Landscape architects can achieve the goal of biodiversity net-gain in their projects by “minimizing harm, regenerating habitat, and protecting and restoring ecologically important areas where nature can prevail.”

She recommended turning college campuses into arboreta and nature preserves, weaving pollinator habitat and native plants into cities, taking out lawns in favor of native meadows and ground cover, and using parks and waterfronts to introduce more biodiversity to the public. Beyond the benefits for wildlife, “the spirit of nature has psychological and spiritual benefits for us,” Park said.

As she outlined in her research, Dr. Park also called for planting design to enhance biodiversity. “We need heterogeneous plant communities with a diversity of functions and structures.” Plants with different flowering times can be brought together in one landscape. This provides food for insects and birds year-round.

One example is the green roof on the historic Old Chicago Post Office building in Chicago, Illinois, which was designed by landscape architects at Hoerr Schaudt to provide seasonal blooms.

Spring. ASLA 2023 Professional General Design Honor Award. The Meadow at the Old Chicago Post Office. Chicago, Illinois. Hoerr Schaudt / Scott Shigley
Summer. ASLA 2023 Professional General Design Honor Award. The Meadow at the Old Chicago Post Office. Chicago, Illinois. Hoerr Schaudt / Scott Shigley
Fall. ASLA 2023 Professional General Design Honor Award. The Meadow at the Old Chicago Post Office. Chicago, Illinois. Hoerr Schaudt / Scott Shigley
Winter. ASLA 2023 Professional General Design Honor Award. The Meadow at the Old Chicago Post Office. Chicago, Illinois. Hoerr Schaudt / Scott Shigley

The largest green roof in the city, it includes more than 40,000 plants, with a high percentage of endemic native plants that provide food for insects and birds. Its restored soils and plants capture 300,000 gallons of stormwater annually.

ASLA 2023 Professional General Design Honor Award. The Meadow at the Old Chicago Post Office. Chicago, Illinois. Hoerr Schaudt / Dave Burk

Many other kinds of projects provide opportunities to restore habitat and at different scales. “We can work at the regional, ecosystem, intermediate or local scales to connect habitat patches and corridors together into a matrix,” Bowers said.

At the Forest Grove wastewater treatment plant in Forest Grove, Oregon, the utility Clean Water Systems came to Biohabitats to improve the function of a sewage lagoon. Water discharged into the lagoon was too warm and had too much nitrogen.

Landscape architects, engineers and scientists at the firm devised a way to use nature-based solutions and leverage biodiversity to solve those problems, creating the Fernhill South wetlands natural treatment system. “We used soils and plants to filter out nitrogen and lower temperatures,” Bowers said.

Fernhill South wetlands natural treatment system, Forest Grove, Oregon. Concept plan illustrating flow paths and habitat diversity. / Biohabitats

Discharged water now flows into a designed set of wetlands, where natural processes — solar radiation and microbes — cleanse water instead of mechanical systems. From there the water flows into a reservoir and then the Tualatin River. This system also means discharged water no longer had to be piped to another facility, saving lots of energy and money in the process.

The series of wetlands are built as “cells” that can be closed off for maintenance. Amid the cells, Biohabitats added woody debris, perches, and nesting areas to restore habitat for a range of species.

Fernhill South wetlands natural treatment system, Forest Grove, Oregon. Reshaping and grading water treatment cells. / Biohabitats

The water treatment area has become a recreational site in its own right and a mecca for birders. “Two-to-three years after completion, the landscape really blossomed.”

And at the city scale, Biohabitats worked with Atlanta to develop a new biodiversity plan that calls for “designing for people, nature, and people in nature.”

Atlanta City Design: Nature, Biodiversity Plan / City of Atlanta Planning Department, Biohabitats

The city is expected to grow to 1.2 million and the region to 8 million in 25 years. As growth occurs, it’s important to protect biodiverse areas and connect these habitats.

Atlanta has one of the largest urban tree canopies in the U.S. and a number of existing patches and corridors. But the city is also losing interior forest, which is 300 feet from any edge. “The city needs that core forest” because many species rely on it.

Analyzing the city in detail, Biohabitats found that interior forest is most intact in the southern and southeastern segments of the city. They then modeled protections for those forest patches, the creation of new patches, and additional corridors to connect them.

Atlanta City Design: Nature, Biodiversity Plan / City of Atlanta Planning Department, Biohabitats

ASLA Releases the First Impact Assessment of Its Business Operations

ASLA Center for Landscape Architecture / Halkin Mason Photography, courtesy of ASLA

The organization is focusing on energy, transportation, and food to reduce its greenhouse gas emissions

By Katie Riddle, Steven Spicer, and Jared Green

ASLA released its first assessment of the greenhouse gas emissions generated by its business operations. This report sets the baseline for ASLA as it strives toward its goal of achieving zero emissions by 2040.

The assessment details the amounts and sources of greenhouse gas emissions generated in 2023 by ASLA operations. This total includes electricity use, magazine printing and shipping, business travel, employee commuting, waste produced, and more. These emissions add up to 320.5 metric tonnes.

ASLA Center for Landscape Architecture / Halkin Mason Photography, courtesy of ASLA

To put that in perspective, the average U.S. home produces approximately one metric tonne of emissions monthly via its electricity use in regions where coal or gas generates power.

“We are demonstrating our climate leadership by being transparent about our impacts. We want to show our members and partners where we are in our journey to zero emissions by 2040. Cutting emissions makes great economic and environmental sense. Let’s learn from each other and move faster together,” said ASLA President Kona Gray, FASLA, PLA.

2023 Operations Baseline

This 2023 assessment was developed in partnership with Honeycomb Strategies, a sustainability consulting company. The company and ASLA team cooperated to collect extensive and complete data:

Of the total 320.5 metric tonnes, ASLA headquarters emitted 124.5 tonnes, or 39 percent, and LAM emitted 196 tonnes, or 61 percent.

Courtesy of ASLA

The assessment for LAM covered the creation and online use of the magazine. By requesting extensive emissions data, ASLA introduced new carbon estimation and measurement practices to its partners. These kinds of requests encourage greater transparency and efficiency in the printing supply chain.

Courtesy of ASLA

The calculations for the Center’s emissions included such factors as electricity use, employee commuting, and business travel.

ASLA Center for Landscape Architecture / Halkin Mason Photography, courtesy of ASLA

The Center used 170,000 kilowatt hours (kWh) of electricity or 13.4 kWh per square foot – substantially below the 16.9 kWh average annual electricity consumption per square foot for administrative office space, according to the U.S. Energy Information Administration (EIA).

Courtesy of ASLA
  • ASLA employees commuted to the office 3,882 times, covering 105,000 miles.
    • 69 percent of trips by car
    • 27 percent by public transit (train, subway, bus)
    • 4 percent by foot or bike
  • ASLA employees traveled 228,000 miles on business trips
    • 96 percent of trips by plane
  • ASLA produced an estimated 7,280 pounds of waste
    • 71 percent of waste went to the landfill and 29 percent was recycled

Reduction Actions

As the 2023 data was collected, ASLA implemented new strategies to reduce emissions in 2024 and beyond. To reduce its emissions this year, ASLA implemented these strategies:

  • Purchased renewable energy credits for 100 percent of the ASLA Center’s energy use.
  • Promoted benefits and incentives for low-carbon commuting.
  • Issued new policies to lessen the effect of business travel.
  • Updated procurement policies to encourage locally sourced and 75 percent vegetarian meals for staff and member events hosted by ASLA at the Center.

“These policies help us decarbonize our operations and serve as an example for other organizations,” said ASLA CEO Torey Carter-Conneen, Hon. ASLA. “This assessment caused us to look into all aspects of our operations to see where we can lower our footprint and save money in the process. We share our impacts so other organizations can see what to track to cut their emissions.”

To empower other organizations and companies to make these changes, ASLA published Towards Zero Emission Business Operations. The guide is designed to help landscape architecture firms of all sizes navigate the transition to zero-emission offices more easily.

It outlines more than 110 strategies landscape architecture firms can implement to reduce their business and project greenhouse gas (GHG) emissions by 50 to 65 percent by 2030 and achieve zero emissions by 2040.

Next steps

In the first quarter of 2025, ASLA will release its 2024 business operations impact assessment with a list of actions to be taken in 2025 to further reduce emissions.

Best Books of 2024

30 Trees: And Why Landscape Architects Love Them / Birkhäuser

Delve into new books on nature, design, and the climate that inform and inspire. Explore THE DIRT’s 10 best books of 2024:

30 Trees: And Why Landscape Architects Love Them
Birkhäuser

30 landscape architects around the world offer personal stories and histories about their favorite tree in this book edited by Ron Henderson, FASLA, a professor of landscape architecture at the Illinois Institute of Technology. The designers explain what the trees evoke and how they were used in a project. Henderson also provides botanical descriptions. Contributors include Shannon Nichol, FASLA, Laurie Olin, FASLA, Mario Schjetnan, FASLA, Gary Hilderbrand, FASLA, Elizabeth Mossop, FASLA, and many others.

The African Ancestors Garden: History and Memory at the International African American Museum / The Monacelli Press, 2024

The African Ancestors Garden: History and Memory at the International African American Museum
The Monacelli Press, 2024

Landscape designer and artist Walter Hood explains how his firm’s powerful landscape at the International African American Museum (IAAM) in Charleston, South Carolina came to be in this beautifully illustrated book. The museum is located at Gadsden’s Wharf, where nearly half of all enslaved Africans arrived in North America. With its African ethnobotanical gardens and infinity pool, the landscape shows “how different worlds can be held in the same space,” Hood says. It unearths and honors the past while providing a space for new dialogue and even celebration.

Brooklyn Bridge Park: Michael Van Valkenburgh Associates / The Monacelli Press, 2024

Brooklyn Bridge Park: Michael Van Valkenburgh Associates
The Monacelli Press, 2024

In plain language, Michael Van Valkenburgh, FASLA, tells the story of how six abandoned shipping piers on the Brooklyn waterfront became a dynamic 85-acre park, the largest addition to NYC’s public space in a generation. Brooklyn Bridge Park was designed to be inclusive — it’s home to barbeques, sports fields, and playgrounds. But it’s also a model of ecological planting and climate resilience. This generous coffee table book offers 250 immersive images and includes a forward by landscape designer Julie Bargmann. It’s the next best thing to going to Brooklyn.

Design by Fire: Resistance, Co-Creation, and Retreat in the Pyrocene / Routledge, 2024

Design by Fire: Resistance, Co-Creation, and Retreat in the Pyrocene
Routledge, 2024

“Feral wildlands and the wildland-urban interface are places where design can make a profound impact,” write Emily Schlickman, ASLA, and Brett Milligan, ASLA, in this timely book that offers 27 strategies for designing with fire. The co-authors focus on five fire-prone zones around the world that share a Mediterranean climate, including western North America, the Mediterranean basin, the Cape of South Africa, central Chile, and parts of Australia. Many scientists no longer view wildfires in these zones as isolated events but rather as connected in a larger system.

The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth / Harper, 2024

The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth
Harper, 2024

“It takes tremendous biological creativity to be a plant. To survive and thrive while rooted in a single spot, plants have adapted ingenious methods of survival,” writes Zoë Schlanger, an evironmental and science reporter for The Atlantic. She weaves together the latest plant science, explaining how plants communicate, sense, learn, and adapt.

Field Sketching for Environmental Designers / Routledge

Field Sketching for Environmental Designers
Routledge

“To learn to really ‘see’ what you draw is to go beyond merely copying what you observe; the ultimate goal is to find the soul and meaning of the landscape,” writes Chip Sullivan, FASLA, professor of landscape architecture at University of California at Berkeley, in this charming how-to guide. A welcome companion for both beginning and advanced drawers, this book’s wealth of inspiration and practical tips will improve the ability of any sketcher. Take it with you on your next walk.

Noguchi’s Gardens: Landscape as Sculpture / ORO Editions, 2024

Noguchi’s Gardens: Landscape as Sculpture
ORO Editions, 2024

Japanese modern artist Isamu Noguchi is famous for his akari light sculptures and public art. But he also crafted landscapes like sculpture, with “space as their primary vehicle,” writes Marc Trieb, Hon. ASLA, a prolific author, landscape historian, and professor emeritus at University of California Berkeley. This book covers Noguchi’s unrealized and built parks, gardens, and playgrounds around the world, offering some rare photographs.

Silt Sand Slurry: Dredging, Sediment, and the World We Are Making / Applied Research + Design, 2024

Silt Sand Slurry: Dredging, Sediment, and the World We Are Making
Applied Research + Design, 2024

“We are manipulating sediments at a tectonic scale,” write the members of the Dredge Research Collaborative — Rob Holmes, ASLA, Brett Milligan, ASLA, and Gena Wirth, FASLA — who have co-authored a compelling call to action to “design with sediment– intelligently, democratically, and equitably.” Sediment is often ignored but is vitally important because it shapes the “current and future conditions of life.” Other key members of the collaborative — Sean Burkholder, Brian Davis, ASLA, and Justine Holzman — contributed essays.

Speculative Futures: Design Approaches to Navigate Change, Foster Resilience, and Co-Create the Cities We Need / North Atlantic Books, 2024

Speculative Futures: Design Approaches to Navigate Change, Foster Resilience, and Co-Create the Cities We Need
North Atlantic Books, 2024

Artist and urbanist Johanna Hoffman, who studied landscape architecture at University of California at Berkeley, calls for partnering with communities to visualize “new and potential worlds.” This world-making can help us “move us beyond what currently exists into what could one day be.” She is inspired by the creative fields of “art, film, fiction, and industrial design” and how they use “speculation to provoke, imagine, and dream into what lies ahead.” The book outlines novel engagement approaches that enable communities to dream big and make vision reality.

What If We Get It Right?: Visions of Climate Futures / One Books, 2024

What If We Get It Right?: Visions of Climate Futures
One Books, 2024

Dr. Ayana Elizabeth Johnson, the keynote speaker for the ASLA 2022 Conference on Landscape Architecture, has written a follow-up to her bestseller: All We Can Save: Truth, Courage, and Solutions for the Climate Crisis. Her new book guides readers through “solutions and possibilities at the nexus of science, policy, culture, and justice.” She brings together visionaries, such as landscape architect Kate Off, FASLA; climate leader Bill McKibben; and MoMA curator Paola Antonelli in a conversation about what a healthier, more equitable future could look like.

Buying these books through THE DIRT or ASLA’s online bookstore benefits ASLA educational programs.

ASLA 2025 Professional Awards Registration Now Open

ASLA 2024 Professional General Design Honor Award. The Bay: “One Park for All” in Sarasota, Sarasota, Florida. Agency Landscape + Planning / HAPS agency / Michael Todoran

ASLA is now accepting submissions for its 2025 Professional Awards Program.

ASLA bestows Professional Awards in the following categories:

  • General Design
  • Residential Design
  • Urban Design
  • Analysis & Planning, which includes the ASLA/IFLA Global Impact Award
  • Communications
  • Research

In each of these categories, juries select a number of Honor Awards and may select one Award of Excellence. One Landmark Award is also presented each year.

Registration must be received no later than 11:59 PM PST on Friday, January 31, 2025. Submissions are due no later than 11:59 PM PST on Friday, March 7, 2025.

Award recipients receive featured coverage in Landscape Architecture Magazine and will be honored at a special Awards Presentation ceremony at the ASLA 2025 Conference on Landscape Architecture, held October 10-13 in New Orleans, Louisiana.

Important Update:

In January, ASLA will launch an upgraded membership system to better serve you and make managing your account smoother and more efficient. To make these changes, we anticipate some scheduled system downtime in January. All systems will be back to normal before the January 31 awards registration deadline.

However, we encourage everyone to register before December 31, 2024, to ensure your registration is confirmed without delay.

FAQs:

Do I need to be a member of ASLA? Yes, individuals must be a member to submit for an ASLA Award.

What is the entry fee? The fee is $400 for each submission. $125 for each ASLA Landmark Award submission.

At COP29, Progress on Climate Finance and Nature-Based Solutions

Landscape architects Kotchakorn Voraakhom, International ASLA, and Pamela Conrad, ASLA, lead a workshop on implementing nature-based solutions at COP29. / Steffi Schüppel

By Pamela Conrad

Last month, global leaders convened in Baku, Azerbaijan, for the 29th United Nations Climate Change Conference (COP29). Dubbed the “Finance COP,” this year’s summit focused on increasing access to climate finance.

The most significant milestone was the adoption of the New Collective Quantified Goal, a historic commitment to channel $300 billion in financing to developing countries by 2035. These funds will help these countries build low-emission economies and adapt to the intensifying impacts of climate change.

Another key takeaway: the increasing global recognition of nature-based solutions as critical tools for addressing climate challenges. The U.S. government underscored this by endorsing the COP29 Declaration on Multisectoral Actions Pathways to Resilient and Healthy Cities. It promotes urban climate action l through integrating these solutions with disaster resilience, sustainable buildings, green jobs, and clean technologies.

These outcomes point to a growing international consensus on the importance of nature-based solution policies, resources, and approaches to combat the climate crisis. But much more financing is needed to scale up these solutions worldwide. The World Bank estimates that $2.4 trillion is needed per year by 2030 to meet climate goals, approximately four times what is currently invested.

Why We Still Must Communicate the Value of Nature-Based Solutions

As someone who has attended several COP conferences over the years, I’ve seen more buzz about nature-based solutions. But there’s a disconnect. While people talk about these solutions enthusiastically, few truly understand what they are. Many will point to mangroves as an example—and they’re not wrong—but these solutions are so much more.

Nature-based solutions work with natural ecosystems to address pressing challenges like climate change, biodiversity loss, and social inequities. They can be implemented in urban and rural areas and at any scale of development.

These solutions include strategies such as restoring wetlands to manage flooding, integrating green roofs in cities to reduce heat, and creating sustainable urban forests to improve air quality. The brilliance of these solutions lies in their multifaceted benefits. They deliver environmental, economic, and social advantages simultaneously.

ASLA 2021 Professional General Design Honor Award. From a Concrete Bulkhead Riverbank to a Vibrant Shoreline Park—Suining South Riverfront Park. Suining City, Sichuan Province, China. ECOLAND Planning and Design Corp. / Arch-Exist Photography

When people see these strategies in action, it’s often a revelation. Suddenly, the abstract concept becomes tangible, and a lightbulb moment occurs. For instance, when attendees at past COP events saw how these solutions could transform landscapes, enhance community resilience, and reduce costs, their enthusiasm shifted into action.

This was the inspiration for launching WORKS with NATURE: Low Carbon Adaptation Techniques for a Changing World at the conference. It serves as a supplement to the UN National Adaptation Plan Technical Guidelines. Developing the guide was a major focus of my ASLA Biodiversity and Climate Fellowship.

The WORKS with NATURE guide highlights one hundred low-carbon adaptation techniques from around the world. / GREENinc landscape architecture, South Africa

The Urgent Need for New Kinds of Infrastructure

The stakes could not be higher. By 2050, 75 percent of the infrastructure we’ll rely on has yet to be built. Meanwhile, without adaptation measures, an estimated 800 million people will be vulnerable to coastal flooding by mid-century. Traditional infrastructure, built primarily with concrete and steel, is not only costly but also carbon-intensive, contributing to the climate crisis we’re trying to solve.

Fortunately, we can shift from traditional gray infrastructure to nature-based solutions, which often cost significantly less and emits a fraction of the greenhouse gases. For every dollar spent on these solutions, the return on investment is roughly fourfold, thanks to benefits like flood mitigation, cleaner air, and increased biodiversity. According to estimates by The Nature Conservancy, these solutions could account for up to 30 percent of the carbon sequestration needed by 2030 to limit global warming to 1.5°C.

Bass River Park, Cape Cod, Massachusetts. STOSS Landscape Urbanism / MILLICENT HARVEY

These solutions make economic, environmental, and social sense. At COP29, this vision inspired a landscape architect-led workshop aimed at helping nations embrace nature-based solutions through practical guidance, shared experiences, and collaborative problem-solving.

How We Can Integrate Nature-Based Solutions into National Adaptation Plans

The COP29 workshop on nature-based solutions was crafted with a participatory design approach, emphasizing inclusion and collaboration. Leaders from Ethiopia, Thailand, Zambia, Bangladesh, Malawi, Timor-Leste, and the Netherlands joined global experts from organizations like the UN National Adaptation Planning group, UN Habitat, ASLA, International Federation of Landscape Architects (IFLA), Architecture 2030, and the International Society of City and Regional Planners (ISOCARP) to share their experiences.

Adefires Worku Gizaw shares implementation lessons from the Ethiopian Forestry Development and the Green Legacy Initiative. / Kotchakorn Voraakhom

Representatives highlighted their countries’ efforts to integrate nature-based solutions into National Adaptation Plans (NAPs). To date, 60 NAPs have been developed globally, with the rest of UN nations to launch their plans by the end of 2025. Each developing country receives $3 million to support the creation of their plans, which guide adaptation priorities tailored to local needs and challenges.

The workshop included a collaborative activity where leaders reflected on pressing challenges, potential solutions, and support needed to implement nature-based solutions effectively. They told us that their countries face a set of pressing challenges:

  • Food security and agriculture vulnerabilities
  • Increasing heat in urban areas
  • Water and sanitation crises
  • Flooding and sea-level rise
  • Livelihood disruptions and cultural heritage preservation
  • Urban climate resilience

Their countries also experience many barriers to implementing nature-based solutions:

  • Coordination difficulties and conflicting interests among stakeholders
  • Lack of landscape-based systematic solutions
  • Limited technical capacity to design and implement nature-based solutions
  • Absence of validation and valuation frameworks
  • Conflicts with existing regulations and compliance mandates
  • Insufficient political support and unclear governance

The leaders then identified ways to overcome these barriers:

  • Building capacity to develop adaptation plans and projects featuring nature-based solutions
  • Creating interdisciplinary advisory boards with unified goals
  • Developing policies that integrate these solutions into broader national strategies
  • Facilitating workshops to engage stakeholders and align priorities\
  • Enhancing coordination across sectors to break down silos

And they stated more support is needed in key areas:

  • Technical training and capacity building for implementing agencies
  • Awareness campaigns targeting policymakers and communities
  • Tools and technologies for monitoring and evaluation
  • De-risking nature-based solutions investments through validation studies
  • Political commitment and willingness to adopt these solutions
Landscape architect and IFLA representative Indra Purs synthesizes feedback from the workshop. / Pamela Conrad

Adao Soares Barbosa, the Vice Chair of the UN NAP / Least Developed Countries Technical Expert Group closed the event, saying: “I hope this guide and workshop inspires nations with technical guidance for implementing nature-based solutions. Sharing lessons learned between developed and developing countries is essential.”

Moving Forward

The momentum generated at COP29 is just the beginning of what must become a sustained global effort. The public and private sectors are projected to invest $90 trillion in major infrastructure projects by 2030, presenting an unprecedented opportunity to integrate nature-based solutions into the foundation of future development. However, less than 10 percent of current adaptation funding goes to green infrastructure, despite its lower costs—around 70 percent less than traditional gray infrastructure.

To bridge this gap, we need robust policies, innovative financing mechanisms, and consistent performance evaluations to demonstrate these solutions’ effectiveness and economic benefits. ASLA’s recent briefs on the economic benefits of nature-based solutions is just the start of an ambitious economic research agenda that will support increased investment. Collaboration between policymakers, landscape architects, and communities will be key to scaling up these solutions and ensuring that nature plays a central role in building a sustainable future.

The path forward is clear: let’s invest in nature to secure a resilient, equitable, and thriving world for generations to come. COP29 may have concluded, but its outcomes will guide us as we tackle the challenges and embrace the opportunities ahead.

Pamela Conrad, ASLA, PLA, LEED AP is a licensed landscape architect, the founder of Climate Positive Design, faculty at Harvard’s Graduate School of Design, and ASLA’s inaugural Biodiversity and Climate Fellow. She was the chair and lead author of ASLA’s Climate Action Plan, 2019 LAF Fellow, 2023 Harvard Loeb Fellow and currently serves as IFLA’s Climate and Biodiversity Working Group Vice-Chair, World Economic Forum’s Nature-Positive Cities Task Force Expert, Carbon Leadership Forum ECHO Steering Committee, and is an Architecture 2030 Senior Fellow.

Floating Wetlands Bring Nature Back to Baltimore’s Inner Harbor

Harbor Wetland at National Aquarium, Baltimore, Maryland. Ayers Saint Gross / Phillip Smith, courtesy of National Aquarium

The National Aquarium’s new Harbor Wetland shows the great potential of creating wildlife habitat in cities. With just 10,000 square feet, it has already drawn otters, herons, ducks, crabs, fish, eels, and jellyfish.

Harbor Wetland at National Aquarium, Baltimore, Maryland. Ayers Saint Gross / Phillip Smith, courtesy of National Aquarium

The $14 million constructed wetland in Baltimore, Maryland was designed by landscape architects at Ayers Saint Gross, a multidisciplinary firm. It improves the harbor environment and advances research and innovation. It’s also a free educational landscape that inspires the public to reconnect with nature.

“Harbor Wetland is an example of how to marry science and art,” said Amelle Schultz, ASLA, PLA, a principal and landscape architect with Ayers Saint Gross. “It leaves no doubt that landscape architecture is a STEM discipline.”

Schultz said the floating wetland may look simple but in reality it’s a complex work of design and engineering. “Only about one-third of the project is visible; two-thirds is below the surface.”

Harbor Wetland at National Aquarium, Baltimore, Maryland. Ayers Saint Gross / Phillip Smith, courtesy of National Aquarium

The wetland has many layers. More than 32,000 native tidal marsh shrubs and grasses form the top. They were planted in recycled plastic matting that will allow the plant roots to grow down into the water, providing habitat for dozens of species and filtering harbor water.

Harbor Wetland at National Aquarium, Baltimore, Maryland. Ayers Saint Gross / Phillip Smith, courtesy of National Aquarium

Amid these plants are shallow channels, with beds of oyster shells that provide additional habitat. Compressed air is pumped into these channels, bringing dissolved oxygen into the harbor and keeping water circulating, like in a natural tidal marsh.

Harbor Wetland at National Aquarium, Baltimore, Maryland. Ayers Saint Gross / Phillip Smith, courtesy of National Aquarium
Harbor Wetland at National Aquarium, Baltimore, Maryland. Ayers Saint Gross / Phillip Smith, courtesy of National Aquarium

This entire system sits on top of another layer of custom pontoons. Their buoyancy is adjusted as the weight of the wetland increases with plant growth. The pontoons also support the walkways and outdoor classroom spaces that line the installation. “Traditional constructed wetlands eventually sink under their weight — this one won’t,” Schultz said.

Sitting at the end of the classroom space, hundreds of feet into the harbor, there is a moment of serenity. It’s easy to forget about all the engineering and technology and just imagine you are in a natural wetland.

Harbor Wetland at National Aquarium, Baltimore, Maryland / Jared Green

And the project also makes it easy to imagine more wetlands. The project supports the aquarium’s long-term ecological research and will inform the creation of future constructed wetlands. The system is designed to help make the case: Sensors embedded in the wetland test the water quality, and researchers are documenting species populations.

Schultz thinks one measure of the project’s success is the incredible range of species that now visit. “The aquarium’s interior exhibitions are built to be natural, but the animals can’t leave. The animals that visit the wetland choose to be here,” she said. Some of the species that visit were a surprise: “American eels are really hard to find in the harbor.”

The grasses are important habitat for many species the aquarium wants to track. As they were growing in, the aquarium even added a plastic coyote to scare off geese, which would have made a meal of them. “It’s more of a joke now than a deterrent,” said Shelley Johnson, ASLA, PLA, senior associate with Ayers Saint Gross.

Harbor Wetland at National Aquarium, Baltimore, Maryland / Jared Green

Harbor Wetland also builds on research conducted on a smaller prototype just a few feet away in the same bulkhead, which was initiated more than 10 years ago. Ayers Saint Gross worked with Biohabitats, McLaren Engineering Group, and Kovacs, Whitney & Associates to advance an initial concept created by Studio Gang.

National Aquarium wetland prototype, Baltimore, Maryland / Jared Green

“Even in the prototype, the aquarium team saw small fish come to the small stream in the middle of the wetland. No one expected that to happen,” Schultz said.

The aquarium thinks Harbor Wetland will boost the local economy. “The wetland will bring more people to the inner harbor,” Johnson said. “Not everyone can afford tickets to the aquarium, but they can visit this.”

School groups are already visiting, where they are given tours by aquarium researchers. The mural that frames the project expresses the aquarium’s hope that more young people in Baltimore will be inspired to join the effort to restore the Chesapeake Bay.

Harbor Wetland at National Aquarium, Baltimore, Maryland. Ayers Saint Gross / Phillip Smith, courtesy of National Aquarium

“Landscape architects led the team to the solution — the technical and scientific aspects, and married that to the public realm,” Schultz said.

The technical work alone realized benefits: their innovations led to a new patent application focused on the integrated buoyancy and aeration system.

Co-Creating a Future That Heals Land and Culture

Bison in Yellowstone National Park / Fokusiert, istockphoto.com

“Indigenous Peoples were the first landscape architects of this continent,” said Lyla June Johnston, during the opening general session of the ASLA 2024 Conference on Landscape Architecture in Washington, D.C. “We have been stewards of this land and made it beautiful and edible. We fed the Earth instead of just letting it feed us.”

Chestnut forests once spanned the east coast from Maine to Georgia, before a blight decimated the trees. “These were not wild forests, but planted by Indigenous Peoples. And Native land stewards evolved those landscapes over time.” Scientists know this from studying soil core samples and fossilized charcoal going back 10,000 years. The data shows that chestnut and hickory trees dramatically spiked 3,000 years ago, and black walnut 2,000 years ago.

Chestnut Grove, Virginia / AidanWarren, istockphoto.com

In the Pacific Northwest, there were once vast, cultivated clam gardens. “You can see them from ancient clam garden walls that augmented natural clam habitat.” These gardens were co-designed with clams because “they are equal to us and have their own nationhood status.”

Clam garden in the Broughton Archipelago, British Columbia, Canada / Wikipedia, Simon Fraser University, CC BY 2.0

In the Illinois region, Indigenous People burned prairies for thousands of years to “maximize productivity and regain nutrients,” Johnston said. “Fire brings new life to the prairie. Flowers emerge in the spring.” Ash from fires also nourished soils and created nutrient-rich grasses that made habitat for bison and deer. “Indigenous Peoples passed on this great heirloom for thousands of years to their children— a living soil system.”

In the Washington, D.C. area, Indigenous Peoples cultivated oyster fisheries for more than 3,000 years. Oyster populations of the Chesapeake Bay are less than 1 percent of what once was.

Johnston is an Indigenous Artist, Musician, Scholar, and Community Organizer of Diné (Navajo), Tsétsêhéstâhese (Cheyenne), and European lineages. She argues that land stewardship should be restored to Indigenous Peoples given they are far better at creating and restoring habitat than Western people.

“People can be a gift, not a virus. We can be creators and a keystone species. We can be in service to the land. We can create edible landscapes that support the well-being of all,” she said.

But to become a keystone species and support global regeneration once again, people need to “first landscape their inner world before they landscape the outer world.” Our global society needs to shift its mindset. Instead of exploiting nature, we need to be its guardian. “Think of a bird bath — it’s not for us, but lets birds rest, drink, and bathe.”

Johnston argued that communities could give more land back to Indigenous Peoples because their guardian mindset is so crucial to protecting biodiverse places and restoring them. “Worldwide, Indigenous Peoples are 5 percent of the population but we manage 80 percent of global biodiversity. Give us more land to manage. We are good at this.”

Johnston was followed by Julia Watson, Author, Lo—TEK Design by Radical Indigenism; Principal, Julia Watson llc; and Co-founder Lo—TEK Institute. She understands traditional ecological knowledge as “inter-related networks of knowledge.”

After many years of working with Indigenous communities and designers, “I came to understand this knowledge is relational and shaped by time and place. It’s different from Western science; Indigenous knowledge is interconnected.”

“There are vast networks of knowledge developed over long periods of time. These networks of knowledge enabled ancestral people to survive and adapt to climate change over thousands of years. You can’t separate their technologies from the people; they are co-evolutionary.”

Watson offered an example: the sea fishing techniques of the Yap people of Micronesia. They created artificial reefs and weirs that catch fish in the outgoing tides. “The technology is 1,000 years old.”

Aech Fish Weirs of the Yap People of Micronesia / Bill Jeffrey, courtesy of Julia Watson
Aech Fish Weirs of the Yap People of Micronesia / Bill Jeffrey, courtesy of Julia Watson

With the colonization of the region, this Indigenous technology was no longer used for fishing. But even after falling into disrepair, the legacy of the infrastructure forms breakwaters that protect these communities today.

Watson said these systems can be brought back along with other traditional ecological knowledge (TEK) systems created by Indigenous communities around the world.

After the success of her book Lo-TEK, Watson has written a follow-up – Lo-TEK: Water, which focuses on ancestral aquatic technologies. It will be released in the spring of next year. The new book includes 22 case studies of traditional infrastructure and 22 contemporary projects infused with TEK that “rebuild ancient knowledge and highlight Indigenous traditions of adapting to climate change.” She organized these technologies in multiple categories: living, co-evolutionary, sovereign, symbiotic, and cyclical.

Watson’s goal is to bring ancestral technologies back into the global discussion about solutions to the biodiversity and climate crises. “Ancestral infrastructure has been deliberately excluded from these conversations. There has been an unlearning of these histories, even though Indigenous People have created the oldest man-made structures on Earth.”

A young fisherman walks under a living root bridge at Mawlynnong village, India. In the relentless damp of Meghalaya’s jungles the Khasi people have used the trainable roots of rubber trees to grow Jingkieng Dieng Jri living root bridges over rivers for centuries. / © Amos Chapple, courtesy of Julia Watson

Books are just one way she advocates for the inclusion of Indigenous design knowledge. The Lo-TEK Institute also offers a Living Earth curriculum for high-school and college level students, featuring 10 Indigenous, nature-based innovations.

And she’s working with firms like Buro Happold to “co-create hybrid technologies of the future” and with attorneys like Comar Molle to protect the intellectual property of Indigenous Peoples. “We can co-create infrastructure with Indigenous knowledge,” protecting their intellectual property at the same time.

Symbiocene exhibition / Dezeen, courtesy of Julia Watson
Symbiocene exhibition / Tim P. Whitby, courtesy of Julia Watson

Watson used her keynote to announce a historic call to action with ASLA and Indigenous partners: Co-create a future that heals land and culture. The call to action was developed by Watson, Johnston, the Indigenous Society of Architecture, Planning, and Design (ISAPD), and ASLA and its Biodiversity and Climate Action Committee. It outlines three key strategies:

  • Respect Indigenous Knowledge
  • Empower Future Generations
  • Help build an Indigenous landscape architects’ network of ASLA members and work in collaboration with groups like ISAPD

During a follow-up conversation with Watson and Johnston, José de Jesús Leal, ASLA, Principal and Director, Native Nation Building Studio, MIG, and member of the ASLA Biodiversity and Climate Action Committee, kicked-off the discussion by asking: “Can Indigenous knowledge outpace our current problems?”

Paul Fragua, a Tribal Elder and architect at MIG, said that while landscape architects and ASLA are celebrating 125 years of American practice this year, Indigenous Peoples have 3,000 years of experience stewarding landscapes. “We need to get started on the next 3,000 years. There is an urgency not for me, but for future generations.”

Johnston sees the landback movement, which has grown in the past five years, as a key way to address our current challenges.

While Native communities are buying land themselves, it’s usually less than 100 acres at a time. “The U.S. government, churches, and private landowners in the U.S. have hundreds of thousands of acres that could be returned to Native stewardship.”

In a few instances, public parks are now being co-managed by the National Park Service and Native Nations. “Having Native Americans in positions of leadership in the Department of Interior and National Park Service enabled that,” she said.

“There are two barriers — getting land back plus a lack of resources,” Leal said. “Native Nations have to be able to take care of the land they get back. It’s not just the actual property, but deep collaboration with the land.”

One approach may help increase resources. In the San Francisco Bay Area, there’s a voluntary land tax people can pay to support local tribal communities. “You can pay it whether you rent or own,” Johnston explained. The funds enable Native communities to buy back more land. Johnston wants to see more of those kinds of funds go directly to grassroots Native community leaders and non-profits that are “revitalizing land and culture.”

To outpace our problems, Watson thinks the “software” that runs our societies needs to change. “A value system is a compass of how to live. These value systems are rooted in a cultural worldview.”

In New Zealand, the Maori have a “software that guides how they take care of the land.” That software shapes their language, which is place based. In effect, their beliefs and worldview and how they communicate are tied to places. “So when we design systems in these places, we need to build the cultural framework of the communities. The belief system is the core.”

Fragua noted that in New Mexico, Pueblo peoples view some mountain peaks as sacred. They are places that transcend this world and connect us to the spiritual world. That is another example of a belief system rooted to a place.

Shiprock, Diné (Navajo) Nation, New Mexico / Wikipedia, Bowie Snodgrass, CC BY 2.0

Landscape architects asked the group questions about how to implement these ideas in contemporary projects.

Johnston and Watson said it’s important to hire Indigenous designers. And Leal added that it’s important to set those relationships in truth. “We need to start fresh relationships and beat stereotypes.” When reaching out to Indigenous designers and communities, “reach out and ask for their voice, but respectfully.”

They also noted that Indigenous design doesn’t necessarily mean creating room for nature at the expense of people. “Indigenous people designed some of the most densely populated cities in South America,” Johnston said. And it’s also not about rewilding landscapes. “American landscapes were never wild to begin with. They were always managed.”

Non-Indigenous designers can also work to “interrupt the harm,” Watson said. “You can document what has been erased and ensure Indigenous landscapes aren’t forgotten.”

Fragua said that many Indigenous communities follow the “great law of peace because there has been so much war. Resilience comes now from resistance [against inequality]. The creator wants us to live as equals.”

And for too long, there has been a separation between people and nature. “We need an integrated approach, a unity where we are part of the world,” Johnston said. Communities need to return to an ancient Indigenous philosophy: “We live in Earth and are born of the Earth. Landscape is a part of ourselves.”

“Culture is living and can change.”

Landscape Architecture Solutions to Climate Change Generate Significant Economic Benefits

Thornton Creek Water Quality Channel, Seattle, Washington / MIG

ASLA Fund releases new research on the economic benefits of nature-based solutions

The American Society of Landscape Architects (ASLA) Fund, a 501(c)(3) organization, has released a new brief on the economic benefits of landscape architecture and nature-based solutions.

The brief is developed for global and U.S. economic policymakers meeting at the UN Framework Convention on Climate Change (UNFCCC) COP29 in Baku, Azerbaijan. ASLA is an official observer of the COP process, and its representatives have attended COPs for the past three years. Pamela Conrad, ASLA, PLA, Founder, Climate Positive Design, is ASLA’s delegate this year.

Dr. Jennifer Egan, PhD, program manager, University of Maryland Environmental Finance Center (EFC) in the School of Architecture, Planning, and Preservation developed the summary and economic benefit estimates. The EFC received a grant from the ASLA Fund to develop these analyses, which summarize findings from research literature, national and international reports, and 175 case studies.

The brief finds that landscape architects increase economic value through their approach to planning and designing nature-based solutions.

Their work on nature-based solutions creates economic benefits in five key areas:

  • Improved Human Health and Livability
  • Expanded Investment and Sustainable Jobs
  • Increased Biodiversity
  • Going Beyond Net-Zero
  • Strengthened Resilience

The Environmental Finance Center created the brief and a supplementary analysis:

Landscape Architecture: Maximizing the Economic Benefits of Nature-based Solutions Through Design: A 10-page brief that summarizes estimates of economic benefits for global and U.S. policymakers.

An Analysis of Benefit Values: 175 Landscape Architecture Case Studies in the U.S.: A 12-page supplementary analysis for economic and landscape architecture researchers and educators that explores economic benefits found in the Landscape Architecture Foundation (LAF)’s Landscape Performance Series Case Study Briefs.

“We listened to global policymakers last year at COP28 in Dubai. They seek to scale up investment in nature-based solutions but need to know how much these solutions cost and their economic benefits,” said ASLA CEO Torey Carter-Conneen, Hon. ASLA.

“We now have some solid numbers that show landscape architects generate significant economic value through the way they design these solutions. But we’ll also start an ambitious research agenda to calculate the economic benefits we currently can’t measure.”

Dutch Kills Green, Queens, New York (before). WRT and Margie Ruddick Landscape / WRT
Dutch Kills Green, Queens, New York (before). WRT and Margie Ruddick Landscape / WRT

Highlights include:

  • Nature-based solutions such as rain gardens, bioswales, and green roofs effectively manage stormwater. These features can be constructed for 5-30 percent less and maintained for 25 percent less than conventional gray infrastructure.
  • Every dollar invested in ecosystem restoration returns $5 to $28 in benefits, depending on the ecosystem.
  • Urban trees provide approximately $88 billion (US$ 2024) in carbon sequestration annually.
  • Every dollar invested in parks and green space can generate between $4 and $11, due to increased tourism, improved property values, and enhanced community health.

ASLA’s Climate Action Plan identified the need for this economic benefits work.