Built environment industry leaders came together for the first time at one table on March 14, 2023 in Seattle, Washington, to discuss a potential coalition on how to rapidly reduce embodied carbon in the built environment.
“ASLA is thrilled to participate in this vitally important group. Embodied carbon is the greenhouse gas emissions that come from extracting, manufacturing, transporting, installing, maintaining, and disposing of materials. The ASLA Climate Action Plan calls for all landscape architecture projects to achieve zero emissions by 2040. The only way we can get there is by significantly reducing the embodied carbon in our projects,” said ASLA CEO Torey Carter-Conneen.
The group was composed of representatives from non-profit organizations and professional commitment groups that are engaged in gathering embodied carbon data from the built environment. They are gathering this data for professional carbon reduction commitment programs or certification systems, along with awareness and engagement activities.
We are at a critical moment where reducing the carbon footprint of the built environment is possible today. But collaboration among industry leaders is necessary to enable a rapid market transformation toward regenerative carbon strategies in the coming years and decades.
The group explored working together to:
streamline embodied carbon data collection and reporting
align on key terminology
build awareness around solutions that building materials can achieve
speak together with a harmonized voice to accelerate progress
Together, this collaboration will accelerate the transition of the built environment towards positive environmental outcomes through design practices and material choices.
As organizations currently or imminently gathering embodied carbon data from the built environment industry, creating tools and resources, and building awareness about this critical issue, we believe that we can move faster together.
The Climate Action Plan was developed by a high-profile Task Force of five landscape architects chaired by Pamela Conrad, ASLA, founder of Climate Positive Design, and a 17-member Advisory Group. It outlines a bold vision for 2040 and a set of 71 actions to be taken by 2025.
By 2040, all landscape architecture projects will simultaneously:
Achieve zero embodied and operational emissions and increase carbon sequestration
Provide significant economic benefits in the form of measurable ecosystem services, health co-benefits, sequestration, and green jobs
Address climate injustices, empower communities, and increase equitable distribution of climate investments
Restore ecosystems and increase and protect biodiversity
“Landscape architects are already helping communities achieve this vision. As we increasingly experience the impacts of the climate and biodiversity crises, we know we need to act faster. We are the only design professionals who bring all the pieces together to plan and design what communities need to prepare themselves for a changing world,” said ASLA President Eugenia Martin, FASLA.
“ASLA has developed its first Climate Action Plan in the spirit of great optimism. We envision communities becoming healthier and economically stronger because they have committed to drawing down carbon, restoring ecosystems and increasing biodiversity, and reducing reliance on vehicles – all while ensuring everyone in their community has equitable access to these benefits,” said ASLA CEO Torey Carter-Conneen.
The ASLA Climate Action Plan is based in science. The Intergovernmental Panel on Climate Change (IPCC) has found humanity can only put a maximum of 340 more gigatons of greenhouse gas emissions into the atmosphere if we want a good chance of only increasing temperatures by 1.5° C (2.7° Fahrenheit), instead of 2° C (3.6° Fahrenheit). To advance the goal of keeping warming to 1.5° C, ASLA signed on to the International Federation of Landscape Architects (IFLA) Climate Action Commitment in 2021. The commitment was presented at the UN Framework Convention on Climate Change (UNFCCC) COP26 in Glasgow, Scotland and is supported by 70,000 landscape architects in 77 countries.
The ASLA Climate Action Plan is rooted in the three goals (practice, equity, and advocacy) and six initiatives of IFLA Climate Action Commitment.
The ASLA plan will direct all ASLA programs and investments through 2025. Goals will be advanced through 21 objectives and 71 actions. Goals and actions will be revisited and updated in 2025 and every five years until 2040 and beyond.
To accomplish the plan, ASLA, as a mission-driven association, has also committed to achieving zero emissions in its operations by 2040. ASLA is calculating baseline Scope 1, 2, and 3 emissions for its 2022 Conference on Landscape Architecture in San Francisco and headquarters operations in Washington, D.C. and has committed to reducing its overall emissions by 20% by 2024. ASLA will use its own journey to zero as a learning opportunity for its members, EXPO exhibitors, and partner organizations.
A companion to the plan – the Climate Action Field Guide for ASLA Members – provides best practice guidance, toolkits, and resources for ASLA members and their firms and organizations, along with corporate partners, to achieve the 2040 vision.
The Field Guide features six toolkits covering 18 strategies, with guidance on how to:
Design Climate Positive Landscapes
Design Pedestrian, Cyclist, and Public Transit-Centric Communities
Reduce Energy Use and Support Renewables
Help Communities Adapt to Climate Impacts
Explore Pathways to Financial Sustainability with Communities
Protect and Increase Biodiversity
Learn from Indigenous Communities Through Collaboration
Build Climate Coalitions
“Landscape architects are uniquely qualified to understand and manage complex, multi-disciplinary challenges and design sustainable, world-changing solutions. We are committed to following the science, and through this Climate Action Plan we will rapidly scale up Climate- and Biodiversity-positive solutions in the U.S. and, through our partnership with IFLA, the world,” said Pamela Conrad, ASLA, Chair of the Climate Action Plan Task Force.
Conrad will represent ASLA and highlight the vision and goals of the ASLA Climate Action Plan at the United Nations Framework Convention on Climate Change (UNFCCC) COP27 in Sharm El-Sheikh, Egypt.
By Roxanne Blackwell, Hon. ASLA, and Caleb Raspler
Congress has passed and President Joseph Biden is expected to sign into law the U.S.’s most comprehensive response to the climate crisis to date — The Inflation Reduction Act. The legislation makes an historic investment of $369 billion to improve energy security, reduce greenhouse gas emissions, and help communities adapt to climate impacts.
Importantly, the Act recognizes and funds landscape architecture approaches to address climate change — from active transportation projects like Complete Streets and recreational trails, to nature-based water infrastructure, community tree planting, ecosystem restoration, and more. Additionally, the legislation makes significant strides in addressing environmental and climate justice and ensuring underserved communities receive resources to adapt to a changing climate.
Landscape architects are uniquely qualified to lead these projects. With their community engagement skills, they are particularly suited to partner with underserved communities. The Act provides tremendous opportunities for landscape architects to work with all communities to plan and design a more resilient and low-carbon future.
Significant funding for programs and projects traditionally led by landscape architects include:
ACTIVE TRANSPORTATION INFRASTRUCTURE
Neighborhood Access and Equity Grant Program: $3 billion to improve walkability, safety, and affordable transportation access through projects that are context-sensitive.
The program provides funding to:
Build or improve complete streets, multi-use trails, regional greenways, active transportation networks and spines or provide affordable access to essential destinations, public spaces, transportation links and hubs.
Remove high-speed and other transportation projects and facilities that are barriers to connectivity within communities.
Remove transportation projects and facilities that are a source of air pollution, noise pollution, stormwater, or other burdens in underserved communities. These projects may include noise barriers to reduce impacts resulting from a facility, along with technologies, infrastructure, and activities to reduce surface transportation-related greenhouse gas emissions and other air pollution. Solutions can include natural infrastructure, permeable, or porous pavement, or protective features to reduce or manage stormwater run-off; heat island mitigation projects in rights of way; safety improvements for vulnerable road users; and planning and capacity building activities in disadvantaged or underserved communities.
Low Carbon Transportation Materials Grants: $2 billion to incentivize the use of construction materials that have substantially lower levels of embodied greenhouse gas emissions in landscape architecture projects, including reimbursements.
NATIONAL PARKS AND PUBLIC LANDS
$250 million for conservation, protection, and resilience projects on National Park Service (NPS) and Bureau of Land Management (BLM) lands.
$250 million for conservation, ecosystem, and habitat restoration projects on NPS and BLM lands.
$200 million for NPS deferred maintenance projects.
$500 million to hire NPS personnel.
$250 million to the Fish and Wildlife Service for wildlife recovery and to rebuild and restore units of the National Wildlife Refuge System.
NATIONAL AND COMMUNITY FORESTRY
$200 million for vegetation management projects in the National Forest System.
$1.5 billion for competitive grants through the Urban and Community Forestry Assistance program for tree planting and related activities.
$550 million for planning, designing, or constructing water projects with the primary purpose of providing domestic water supplies to underserved communities or households that do not have reliable access to domestic water supplies in a state or territory.
$4 billion for grants, contracts, or financial assistance to states impacted by drought, with priority given to the Colorado River Basin and other basins experiencing comparable levels of long-term drought.
$15 million to provide technical assistance for climate change planning, mitigation, adaptation, and resilience to Insular Areas – U.S. territories.
National Oceanic and Atmospheric Administration (NOAA): $2.6 billion for grants, technical assistance, and cooperative agreements that enable coastal communities to prepare for extreme storms and other changing climate conditions. This includes projects to support natural resources that sustain coastal and marine resource dependent communities and assessments of marine fishery and marine mammal stocks.
$50 million for competitive grants to fund climate research related to weather, ocean, coastal, and atmospheric processes and conditions and impacts to marine species and coastal habitat.
ENVIRONMENTAL AND CLIMATE JUSTICE
$3 billion in competitive grants to address clean air and climate pollution in underserved communities.
$33 million to collect data and track disproportionate burdens of pollution and climate change on environmental justice communities.
$250 million for the General Services Administration to convert facilities to high performing buildings.
$2.1 billion to purchase low carbon materials.
$975 million for emerging and sustainable technologies and related sustainability programs.
$20 million for hiring new personnel to conduct more efficient, accurate, and timely reviews for planning, permitting and approval processes.
Department of Agriculture: $19.4 billion to invest in climate-smart agriculture practices and land interests that promote soil carbon improvements and carbon sequestration.
Department of Energy: $115 million for the hiring and training of personnel, the development of programmatic environmental documents, the procurement of technical or scientific services for environmental reviews, the development of environmental data or information systems, stakeholder and community engagement, and the purchase of new equipment for environmental analysis to facilitate timely and efficient environmental reviews and authorizations.
Department of Housing and Urban Development: $837.5 million to improve energy or water efficiency or the climate resilience of affordable housing.
Greenhouse Gas Reduction Fund (GGRF): The fund will help efficiently finance projects, including landscape architecture projects, to reduce emissions through active transportation, ecosystem restoration, energy and water efficiency, and climate-smart agriculture. The fund will receive $27 billion total, with $8 billion earmarked for low-income or otherwise underserved communities. Funds will flow through regional, state, local, and tribal green banks. And the GGRF will provide the institutional foundation for a National Climate Bank Act.
Roxanne Blackwell, Hon. ASLA, Esq., is director of federal government affairs, and Caleb Raspler, Esq., is manager of federal government affairs at the American Society of Landscape Architects (ASLA).
The Cultural Landscape Foundation (TCLF) announced Julie Bargmann has won the inaugural Cornelia Hahn Oberlander International Landscape Architecture Prize for her innovative work that regenerates neglected, often polluted, communities. The biennial award of $100,000 will include two years of public engagement focused on Bargmann’s work and the state of contemporary landscape architecture. The prize is named after German-born Canadian landscape architect Cornelia Hahn Oberlander, FASLA, who passed away from complications from Covid-19 earlier this year at age 99. TCLF states that the prize is bestowed on a recipient who is “exceptionally talented, creative, courageous, and visionary” and has “a significant body of built work that exemplifies the art of landscape architecture.”
The Oberlander Prize jury said Bargmann, professor of landscape architecture at the University of Virginia and founder of D.I.R.T. (Dump It Right There) Studio, has been “a provocateur, a critical practitioner, and a public intellectual. She embodies the kind of activism required of landscape architects in an era of severe environmental challenges and persistent social inequities.” She is known for her work regenerating “contaminated, neglected, and forgotten urban and post-industrial sites.”
In her own words: “unearthing the raw ingredients of design from waste and wastelands defines my life’s work.” And this passion has driven her to “seek a larger canvas, namely, post-industrial cities and regions. There exists massive potential and sublime beauty in places that may seem, at first blush, to be trashed. Sites, neighborhoods, entire cities—they are full of energy waiting to be recognized, released, and given new form.”
TCLF states that Bargmann’s aesthetic approach is “strongly influenced by the work and writings of Robert Smithson, the American artist known for his land art installations including Spiral Jetty, and the American artist Eva Hesse. Bargmann describes her approach as ‘rigorous intuition or intuitive rigor.'”
Bargmann and D.I.R.T. are known for leading conceptual landscape designs that guide multi-disciplinary collaborations with architects, historians, engineers, hydro-geologists, artists, and the communities with which she engages.
A few of Bargmann’s key projects:
For the Vintondale Reclamation Park in Vintondale, Pennsylvania, which was completed in 2002, Bargmann collaborated with historic preservationist T. Allan Comp, hydrologist Bob Deason, and sculptor Stacy Levy on a 35-acre site in coal country designed as a “natural filtration system” that addresses polluted mine runoff. Entitled Acid Mine Drainage and Art: Testing the Waters, this “model of bioremediation” helped Bargmann win the 2001 National Design Award from the Smithsonian Cooper-Hewitt Museum. She explains that “Vintondale is the project that I feel launched D.I.R.T. and still defines its trajectory.”
Her work on the Urban Outfitters Headquarters at the U.S. Navy Yard in Philadelphia, Pennsylvania won Bargmann an ASLA Professional Award in 2014. According to TLCF, the project “became a model for the artistic and ecologically sound reuse of materials, including concrete chunks nicknamed ‘Barney and Betty Rubble,’ as well as brick, rusted metal, and other materials.” The project shows that reusing materials is not only beautiful but also reduces greenhouse gas emissions. Reusing concrete and buried train tracks saves the tons of embodied carbon emissions in these materials and avoids creating new materials that generate more emissions. A greater focus on reused and recycled landscapes is needed in the age of the climate crisis. The ASLA awards jury also noted that the “site perviousness was increased by about 800 percent.” For this project, Bargmann worked with architects at Meyer Scherer & Rockcastle, engineers with Advanced GeoServices, Corp., and environmental engineers with Blue Wing Environmental.
And in 2019, in Detroit, Michigan, Bargmann designed the 8,000-square-foot Core City Park in partnership with developer Philip Kafka of Prince Concepts, architect Ishtiaq Rafiuddin, and project manager Randy Pardy. The park is another ingenious model of artful reuse — almost all design elements were unearthed from the site, including “pieces of a demolished late-19th century fire station, the walls of a bank vault, and other excavated artifacts.” TCLF also calls the park an urban woodland, with tree groves that “allow visitors to break away from the city without leaving it.”
ASLA announces the 2021 Professional Award winners. The 40 winning projects exemplify the highest level of achievement in the profession, and the professionals themselves will be honored at ASLA’s Conference on Landscape Architecture, Nov. 20 in Nashville, TN.
Winners each year are chosen by a jury panel representing a broad cross-section of the profession, from the public and private sectors, as well as academia. The 40 winners were chosen from 486 submissions from around the world. Award categories include: General Design, Urban Design, Residential Design, Analysis & Planning, Communications, and Research. In addition, one Landmark Award is also selected each year.
“This year’s winners demonstrate how landscape architects are increasingly leading the planning and design of healthy and resilient communities for all,” said Torey Carter- Conneen, CEO of ASLA. “Landscape architects are advancing communities’ diversity, equity, and inclusion goals in significant ways.”
Professional Award recipients, their clients, and advisors will be honored in-person at the awards presentation ceremony during the ASLA 2021 Conference on Landscape Architecture in Nashville, TN on Saturday, November 20th, at 6pm ET.
ASLA announces the 2021 Student Award winners. The 35 winning projects exemplify the highest level of achievement by future landscape architect professionals. The students themselves will be honored at the ASLA Conference on Landscape Architecture, Nov. 20 in Nashville, TN.
Winners each year are chosen by a jury panel representing a broad cross-section of the profession, from the public and private sectors, as well as academia. The 35 winners were chosen from 440 submissions of projects from around the world. Awards categories include: General Design, Urban Design, Residential Design, Analysis & Planning, Communications, Research, Student Collaboration, and Community Service.
“This program not only honors the tremendous creativity and passion of these future landscape architect leaders, it also highlights the extraordinary contributions they will make to communities upon graduation,” said Torey Carter- Conneen, CEO of ASLA.
A Landscape Architect’s Outdoor Artwork — Harvard Magazine
“Decades later, that synthesis was part of what propelled him toward a master’s degree in landscape architecture, after 20 years as a curator, graphic-design artist, set designer, and furniture designer. ‘I got to a point in my work as an artist where I felt like I needed some traction in a way that I wasn’t quite finding in the arts,’ [Todd Gilen] says. ‘Landscape architecture has a kind of scientific rigor about it. It’s a discipline that has a basis in both science and the arts.'”
So Long, Traditional Lawn. The New Turf Trends—From Wildflowers to Fescue — 08/27/21, The Wall Street Journal
“‘I have an enormous moss garden just naturally because I don’t do anything to it,’ said Sandra Youssef Clinton, a landscape architect in Hyattsville, Md. Sixteen large oak trees provide constant shade, she said. Though fans of classic turf tell her, ‘Oh, you should get rid of that, it looks so terrible,’ Ms. Clinton finds it quite beautiful. Said Mr. Moore, ‘Even the word ‘moss’ conjures elves and fairies and deep forest.'”
Good News: The Most Popular Material on Earth Is Great for Storing CO2 — 08/27/20, Fast Company
“Our Earth is heating up because of all the carbon dioxide in the air. But even if we can suck that much CO2 out of the atmosphere, there’s still a problem: What do we do with all of it once it’s recaptured? The short answer is, put it into products. The longer answer is, put it into the right products. Specifically, concrete.”
Study Suggests Bike Lanes Do Not Lead to Displacement, Gentrification — 08/27/21, Bike Portland
“The installation of new bike infrastructure in neighborhoods does not lead to displacement of people of color, and low-income areas received more “hard” facilities like buffered or protected bike lanes than high income areas, according to a new study published in July by Elsevier.”
After Years of Failure, California Lawmakers Pave the Way for More Housing — 08/26/21, The New York Times
“Suddenly zoning reform has been thrust to the top of the urban agenda. Cities including Charlotte, N.C.; Minneapolis; Portland, Ore.; and Sacramento have moved to allow multifamily buildings on lots previously limited to single-family houses. The issue is now starting to attract higher-level attention: In the past two years 10 states, including Connecticut, New Hampshire, Montana and North Carolina, have considered bills to reform local zoning rules.”
In Fire Scorched California, Town Aims to Buy the Highest At-Risk Properties — 08/23/21, NPR
“The idea is to connect the burnt out lots to the town’s existing park land. That’s good for adding more recreation but it could also work as a fuel break. Efseaff’s department could strictly manage forests like this with the hopes that the next wildfire might slow down here and give firefighters a chance.”
In a Warming World, Consider the Mist Garden — 08/19/21, Bloomberg CityLab
“Designed by landscape architects Quennell Rothschild & Partners, the new mist garden features 504 evenly spaced fog nozzles atop a new plaza that fills in the 310-foot pool end to end, even keeping the original 1964 stone coping. The new plaza’s edges are paved in a pattern of overlapping triangles, a nod to the Art Deco architecture of the park’s first World’s Fair in 1939, as well as Manhattan landmarks like the Chrysler Building and Rockefeller Center. Concrete lounges make it possible to simulate a spa day in the middle of Queens’ largest park.”
How a Pioneering Garden Designer Inspired Vogue’s Fall Fashion Fantasy — 08/17/21, Vogue
“‘Should it not be remembered that in setting a garden we are painting a picture?’ So asked Beatrix Farrand in her 1907 Scribner’s essay ‘The Garden as Picture.’ A pioneering American landscape architect whose career spanned the Gilded Age, the Roaring Twenties, the Great Depression, and two world wars, Farrand wrote, ‘The two arts of painting and garden design are closely related, except that the landscape gardener paints with actual color, line, and perspective…while the painter has but a flat surface on which to create his illusion.'”
In rare situations, some landscape architects and designers may specify Forest Stewardship Council (FSC)-certified tropical hardwoods for outdoor spaces because there may be no good alternatives. But imagine if instead of just placing a hardwood order and hoping the wood was actually sustainably harvested, designers partnered with conservationists and scientists to preserve the forest from which the wood is cut.
The multi-discplinary team behind Brooklyn Bridge Forest beat 200 competitors from 37 countries to win top prize. The team was led by Pilot Projects Design Collective, which includes landscape architect Christine Facella; along with the Wildlife Conservation Society, Cities4Forests, The Nature Conservancy, Grimshaw Architects, and Silman, a structural engineering firm.
According to the team, one of the best experiences in NYC is to stroll the upper wood deck of the Brooklyn Bridge, which is why more than a million people do it each year. The genius of John Roebling, the bridge’s designer, was to “contrast iconic stone towers and graceful steel cables with the warmth and softness of a wooden boardwalk to create the ultimate setting for the pedestrian,” the team states.
Pilot Projects Design Collaborative and its partners propose making Brooklyn Bridge an even better walking and bicycling experience by expanding the upper wood deck of the bridge and creating new biodiverse green spaces at either end of the bridge and areas for pop-up markets.
The bridge’s existing Greenheart (Ocotea rodiaei or Chlorocardium rodiei) wood promenade is a mile long and comprises 11,000 planks that are approximately 4-feet wide by 16-feet long. Tropical hardwoods like Greenheart used for boardwalks and promenades typically lasts around 30 years.
The team explored replacing the hardwood with plastic lumber, but found the planks to be too carbon intensive. They also looked at domestic hardwood, like Black Locust, which is always preferable to tropical hardwoods, but found that the lumber doesn’t come in sizes that are long enough. The team also looked at concrete and wood composites but found using those materials would require structural updates to the bridge. So they proposed replacing the existing planks, sourced from an unknown forest in South America 30 years ago, with sustainably harvested Manchiche (Lonchocarpus castilloi) from the Uaxactú Community Rainforest.
Instead of the city spending $2 million for the new wood, the public would sponsor individual wood planks at a cost ranging from $400 to $5,000 and in turn have their name laser- or fire-etched into a plank. With the funds raised, the community forest, which is found in the larger 6 million-acre Maya Biosphere Reserve, would be protected and generate wood for the promenade in perpetuity.
The communities of Uaxactún have reached an agreement with the Guatemalan government: If resources are harvested sustainably, their land management rights are respected. Through a “community concession” system, the people of the forest can “harvest fruit, medicinal, and ornamental plants, chicle (a natural chewing gum), and a limited amount of timber,” said the Brooklyn Bridge Forest team. The communities coordinate with the Guatemalan government, the Wildlife Conservation Society, and FSC.
Under the terms of the land management plan, tropical hardwood trees can be harvested at the rate of 1 tree per 40 acres using small-scale equipment. After a large tropical hardwood tree has been removed, smaller trees would be planted in the area that has been disturbed.
The scientists with the conservation organizations involved argued that “the communities’ low-impact timber harvesting provides jobs as well as resources for health and education. These opportunities in turn have given the communities a long-term stake in protecting the forest. Community-patrols defend the forest from the numerous threats in the Maya Biosphere Reserve, including wildfires, illegal logging and hunting, and in recent years, cattle ranching operations linked to international drug traffickers.” (Learn more).
Furthermore, the scientists believe that the low-impact logging practices undertaken in Uaxactún would have “very little effect on wildlife populations.” And funds from the sponsorship of planks would go to important research on the ecological impacts of controlled logging in these environments.
One of their central arguments: “Most timber harvesting in the tropics is not carried out with the level of care practiced in Uaxactún. In these other places there is often very little regulation, no long-term plan, and no research to assess impacts. Only a fully transparent model with ample opportunity for participation and investigation can guarantee that we are procuring wood in a way that supports forest protection.”
The team thinks this intentional approach could be used for other sustainable hardwood harvesting projects. They point to a few historic models: Every 20 years, the Ise Shrine in Kyoto, Japan, is rebuilt with the exact same dimensions using 10,000 cedar logs. The shrine, which has been rebuilt in this way for the past 1,300 years, has set aside a forest that will be harvested in 200 years for the ritual reconstruction. And in Sweden, in the 1800s, some 300,000 trees were planted to create wood for the Swedish navy. When they were ready to harvest in 1975, Sweden no longer built ships out of wood, but the 900-acre forest of oaks remains preserved.
The winning submission in the young adult category may have found a solution that avoids the tropical hardwood issue altogether. Do Look Down, a proposal created by Shannon Hui, Kwans Kim, and Yujin Kim, from Hong Kong, NYC, and Berkeley, California, aims to incorporate glass instead of wood for the promenade. There would be thrills galore while looking down, at least for those not afraid of heights.
Interview conducted at the ASLA 2019 Conference on Landscape Architecture in San Diego.
Over the past few decades, how much progress have we made towards achieving sustainable landscapes? What practices promoted through the Sustainable SITES Initiative® (SITES®) have landscape architects now widely adopted? What low-impact material alternatives do landscape architects now widely use?
In general, we have made strong progress toward sustainable landscapes in some areas. Green infrastructure — including bioretention, bioswales, rain gardens, even green roofs — are now pretty widely used, especially in urban environments. Their performance and cost benefits are well-documented.
Landscape architects are getting a handle on how to employ them in a functional and artful way. Landscape architects are also starting to speak the language of civil engineers and doing great collaborations in the area of stormwater management. This whole area of SITES and sustainable site design has been really successful.
Landscape architects are also designing with native plants and plant communities in mind, and many are avoiding invasive plants. If only we could get the nursery industry to not stock invasive plants, we would be OK. But even in urban settings, landscape architects are conceiving of plant communities as habitat as well as having aesthetic value.
Where are the major gaps? Where does progress need to happen the most?
Use of materials with reduced environmental and health impacts are lagging behind. This is because clear and comparable information about the carbon footprint, resource use, manufacturing impacts, and toxicity of materials and products is not widely available.
Information transparency is perhaps the biggest challenge when trying to reduce the environmental and human health impacts of materials and products. LEED, SITES, and the Living Building Challenge offer credits encouraging information transparency, but these credits are still among the least achieved.
Product manufacturers do not provide information on embodied carbon, resource use and waste, energy and water use, and toxicity impacts. Human health impacts may be the most challenging to identify given many manufacturers claim the constituents of their products are proprietary and therefore will not release information on the types of chemicals used or produced and their quantities.
The habitat and cultural impacts of raw material extraction are often an out of sight out of mind issue. For example, we don’t see the impacts of harvesting tropical hardwood lumber from the Amazon, so it doesn’t seem so problematic to use it. We don’t see the ecosystem decline after the removal of the keystone species tree that is cut to make tropical hardwood lumber. We don’t hear about the murders of indigenous people to intimidate them to leave their protected land so tropical hardwoods can be harvested. And we don’t know that there is a 78 percent chance that the tropical hardwood we are using was harvested illegally (Greenpeace 2014).
Through Climate Positive Design, Pamela Conrad, ASLA, has devised a comprehensive approach for designing and constructing landscapes so they sequester more carbon than they emit over their lifespans, transforming them into net carbon sinks. Through her design toolkit, she recommends swapping carbon-intensive materials with lower-carbon options and planting more greenhouse gas-absorbing trees and shrubs. As you just mentioned, one of the issues you have identified is the lack of third party-verified environmental product declarations with publicly accessible data. How can we get full transparency around the environmental impact of landscape products?
First, I want to say that balancing carbon onsite is a critical aim, and Conrad’s design toolkit is wonderful. It’s going to have a transformative impact on site design and material and product specifications.
Embodied carbon of materials is a far more accurate indicator of the impact of producing a building material or product than embodied energy. Embodied energy is not as accurate because all energy sources do not have equal impact on the environment. Some will be almost carbon neutral, like wind power, and others, like coal, will have very high embodied carbon and a substantial environmental footprint.
But while carbon considerations are heavily prioritized in decision making in the building fields, they do not tell the whole story. The human health impacts of materials and products, which can be very substantial, tend to fly under the radar.
PVC, a plastic that is used in countless construction products, has lower embodied carbon than some other plastics, but it can be extremely toxic to humans in manufacture, use and disposal, particularly if it is burned or heated to very high temperatures. Designers need to consider these impacts, but the only way they’re going to know about them is for manufacturers to tell us exactly what is in the products and what by products are produced.
Information transparency by product manufacturers is an area that lags behind other sustainability considerations. I did a content analysis study back in 2012 of the websites of all exhibitors at the 2012 ASLA conference. We looked at what kind of information they’re providing on the impacts of their materials and products, and the steps they’re taking to make them more sustainable. Less than 1 percent provided either life cycle assessment (LCA) or environmental product declarations (EPD).
I’m replicating that study right now, seven years later. I don’t have the results yet, but I suspect it’s going to be closer to 10 percent providing that kind of information. There is progress being made, but we still not enough information for designers to use to compare similar products.
SITES and LEED have likely had a slight transformative impact on the information that product manufacturers provide. But the fields of architecture and interior design are ahead of us. If we did a content analysis of their product websites, we would probably find somewhere between 20 and 30 percent provide environmental product declarations.
The main way to address the lack of information is for landscape architects and designers specifying site construction products to talk to product manufacturers and ask for information about the environmental and human health impacts of their products. Telling manufacturers — “Well, I’m considering using your product but your competitor, Company X, has an environmental product declaration, so I’m going to go with them” — is only way to make it happen.
Of course, one can earn LEED and SITES credits for companies that offer some material transparency. But I don’t know if that’s making change as much as designers constantly asking for that information.
Concrete production accounts for around 8 percent of global greenhouse gas emissions. Cement, which is a primary ingredient in traditional concrete, is the second-most used natural resource after water. You have written about the many low-carbon concrete options companies are developing, including carbon-sequestering concrete, concrete that requires lower amounts of energy to produce, and concrete primarily made up of fly ash and other waste products. What will it take to replace the conventional polluting concrete with these new alternatives?
These alternatives are so new that many are not widely available on the market yet. Some are still in development. But of those on the market, only the earliest adopters are specifying them. They’re better used in Europe, because many are European technologies.
In the U.S., landscape architects oftentimes don’t specify concrete mixes. Landscape architects need to convince the people who do — the engineers, the contractors and the Departments of Transportation — to do it.
Contractors are understandably nervous about using new concrete mixes and are not easily convinced to change. Durability is such a key consideration in the performance of concrete, and it is still a question with the new low carbon technologies and mixes. It’s just going to take time and experimental applications. If the applications are monitored and the data on performance published, adoption of these technologies will happen.
Solidia Technologies’ Solidia cement (low Portland Cement) and Solidia concrete (injected with carbon) was successfully tested in multiple applications by the Federal Highway Administration (FHWA) in east coast locations. This is one way that these technologies can trickle down into the site construction market. If the FHWA or U.S. Department of Transportation believes in it and has it as either a standard or alternative specification, then the contractors in that area are much more likely to want to use that product.
D.I.R.T. Studio artfully integrated recycled concrete, bricks, and rusted metal found onsite at the Urban Outfitters headquarters at the Philadelphia Navy Yard, creating a rich, layered environment that demonstrates sustainable values. Do you see this recycled landscape aesthetic becoming more popular? What trends do you see in the use of recycled materials?
The answer is both yes and no. There’s a type of project that can use reclaimed material successfully. Not all clients want that aesthetic and not all project budgets can afford it.
Some projects will never be able to incorporate reclaimed materials because of the budget and bid structure. In a public bid project where the contractor is not onboard until after the bid set is complete, there may be insurmountable obstacles to use of reclaimed materials. It is best if one can design with reclaimed materials in hand, rather than setting out to find them after the bid documents are complete. If you set out to find a nine-by-nine reclaimed cypress post for the pergola that is fully detailed, you’re never going to find it. You need to find the material first and then design with it.
Cost can also be an issue. Once located, reclaimed materials sometimes need to be stored for several months until construction. And the material may need work such as removal of nails, cleaning, resurfacing and even regrading.
I don’t want to discourage this: if it’s a landscape architect can pay this kind of attention to the reclaimed materials, that’s great, but it’s just not feasible for every project.
There has been a growing movement to end the extraction of Ipe and other tropical hardwoods, which is highly destructive to rainforest ecosystems. Landscape architects like yourself and Michael van Valkenburgh, FASLA, have instead promoted the use of native hardwoods like black locust. There are also composite, thermally modified, polymerized, and acetylated wood products. Help us navigate the landscape of tropical hardwood alternatives. How should landscape architects make a decision?
There is absolutely NO reason to use tropical hardwood lumber anymore. There are good alternatives that exist that perform in some cases better than tropical hardwoods and have far lower impacts to ecosystems. Ipe, Cumaru, some of the other tropical hardwoods are keystone or umbrella species in their ecosystems.
Once that one tree is removed, studies show that the forest, plants, and animals for acres around it that depended on that one tree will decline. Within five years that land is usually turned over to grazing land for cattle. Because of this fact, even selective harvesting is not a good practice for rainforest trees.
There are also unseen social impacts to using tropical hardwood lumber. Tropical hardwood extraction has devastating social impacts to indigenous communities. Few designers know that since 1985 there have been 1,700 deaths in the Amazon over land disputes that primarily have to do with illegal logging. Also, tropical hardwoods are not a renewable material because it takes 90 to 200 years to grow a comparable tree, but the lumber from that tree is only going to be in use for about 30 years.
There are many alternatives to tropical hardwoods now on the market. Thermally modified wood, acetylated wood, polymerized wood– all three of those use heat and either steam or acetic anhydride or a polymer cross-linking agent, furfuryl alcohol, to modify the sugars of the wood, so that decay organisms no longer recognize them as food. All three of these lumber treatments are non-toxic. They make the wood more dimensionally stable, harder, and much more competitive with the durability of tropical hardwoods. And they are easier to build with than the extremely dense tropical hardwoods.
Another alternative to tropical hardwoods is fused bamboo, which has been on the market in China for close to ten years. It’s a really hard product similar to Ipe, so it needs carbide blades to cut and drill it. It’s a very durable product, and unlike, Ipe, uses a clip system that avoids the pre-drilling and screwing necessary for Ipe boards. It is a rapidly renewable product, with rapid growth of the bamboo every three to five years.
Fused bamboo is essentially stripped, carbonized, and impregnated with phenolic resin, which may or may not have some toxicity issues. It does contain formaldehyde, but the jury’s still out on that. Anyway, it performs and weathers really well. It’s easily oiled and rejuvenated, guaranteed for 10 years in commercial applications and 30 years in residential applications.
And then of course black locust is also a good alternative. It can be challenging to use because black locust trees do not grow straight, so when you cut it into lumber, it tends to want to return to its irregular form. But it is starting to be grown on plantations and should have a straighter habit when farmed. Also, use of shorter lengths can prevent its tendency to warp.
Innovative new materials in development include concrete that can absorb air pollution and clean the air, bricks that can be grown, and plants that can be engineered to produce light. What emerging material technologies are you most excited about? Which have the greatest potential to improve our built environment?
The process increases the surface area of these particles, creating micro-cracks and dislocations of structure at the nano scale, allowing for greater surface area and greater reactivity with respect to the processes of cement. It’s possible to achieve a concrete with 70 percent fly ash and just 30 percent cement. Once this finds its way into the market, it’s going to really transform concrete. That said, fly ash is only around as long as we’re burning coal. In Europe, for instance, they’re burning a whole lot less coal, so fly ash is not nearly as prevalent as it is in the U.S. anymore.
The other thing I’m excited about is recycled plastic aggregate concrete (RPAC), which is in the testing and case study application phase. There’s a whole lot of waste plastic in this world and if we can find a way to use it instead of non-renewable virgin aggregates, we should. The technology is still in the research phase, but preliminary results of RPAC as fine aggregate show an increased flexural strength, tensile strength, and density. There is so much on the horizon to improve the environmental and human health footprint of concrete.
Given SITES v2, which covers landscapes, and LEED v4, which covers all types of buildings, now have a number of synergies designers and developers can take advantage of, the potential market impact of SITES is even greater, Beckham said.
Calkins argued that it’s critically important landscape architects and designers leverage SITES to reduce the harvesting of Amazonian hardwoods for seating, decks, and boardwalks. “Some 18 percent of the Amazon has been cut down in the past 20 years.” With SITES, “we can transform the market away from tropical hardwoods.” SITES incentivizes this transformation with its prerequisites that “eliminate the use of wood from threatened tree species.”
For example, Ipe, a rare hardwood that appears once every 7-30 acres and is a signature species in the Amazonian rainforest, has often been used in landscapes because of its durability. But SITES — which refers to plants on the Convention on International Trade in Endangered Species (CITES)’s list of those threatened with extinction and the International Union for Conservation of Nature (IUCN) “red list of threatened species” — prevents the use of this endangered tree species in SITES-certified landscapes.
One big problem with the current approach, Calkins explained, is the “IUCN list is dreadfully behind.” Many tree species were last assessed more than a decade ago, so it allows many woods that are no longer plentiful, like Cumaru.
Another issue: In the Pará state of Brazil, some 28 percent of hardwoods are harvested illegally. Even some Forest Stewardship Council (FSC)-certified woods’ documentation is forged, with “shady chains of custody.” And while the Lacey Act is designed to prevent American companies from purchasing illegally-harvested rare Amazonian hardwoods, “fraud still happens.”
Instead of trying to find the few sustainably-harvested rainforest hardwoods, Calkins called for using alternatives like fused bamboo lumber, which is rapidly renewable and outperforms Ipe in durability; American Black Locust lumber, a hardwood native to the Ozarks and Appalachian regions and can be harvested in one-third the time of Ipe; thermally-modified woods, which are heated so they are twice as hard as the original wood and are disease resistant; polymerized woods, which has been developed in the European Union; and acetylated woods.
Furthermore, “landscape architects need to see environmental product declarations and quantifiable data” for all the products they are considering specifying. The architecture field is “way ahead” of the landscape architecture field in this regard of measuring and verifying the life cycle of products, as there are already a number of independent 3rd party product verification systems.
For Calkins, who researches the sustainability of landscape products, just finding basic information on wood products for landscapes is a challenge. “Corporate sustainability reports are a source of information, as are marketing brochures.” But, again, she is looking for independent 3rd party verification of any sustainability claims, and those don’t seem to exist for landscape products.
To shift the marketplace, landscape architects need to “ask more questions of product manufacturers, demand they disclose information and be transparent, and use environmental product declarations when specifying.”
According to landscape architect April Phillips, who has designed and built SITES-certified projects, the key is to track the sourcing of all materials from the get-go. In a “living roof native landscape” she created for 38 Dolores in San Francisco, she used 44 percent recycled materials and 60 percent regional ones.
Phillips also made the case for environmental product declarations, claiming that too often the only ones she can find are from products made in the Netherlands or New Zealand. And importing these products to the U.S. only adds to projects’ carbon emissions and is discouraged in SITES.