by Bryce Carnehl, Affiliate ASLA
Climate Action Plan and Collaborators
In 2022 the American Society of Landscape Architects published their Climate Action Plan (CAP), which sets a bold vision to be a zero emissions profession by the year 2040. Increasing the percentage of green space, selecting low carbon materials, enhancing biodiversity, and many more ideas are offered within the plan. Developed by a team of leading landscape architects, this plan, and accompanying field guide, provides a framework for landscape architects to achieve this goal.
As one can imagine, it takes a team of collaborators and partners to build such a plan and execute such a vision. Leading the drive to this vision is the ASLA Climate Action Committee and subcommittees. This committee is charged with building road maps, actions, guides, and identifying collaborators to help fulfill the goals of the CAP. One such collaborator group is the Corporate Member Committee and its roster of manufacturers and vendors that support landscape architects and the landscape industry markets. With approximately 75% of landscape architecture project emissions coming from materials, collaboration between these groups is crucial to realize a zero emissions profession. As these committees focus up the value chain in the economies of landscape architecture, there is an excellent opportunity for the ASLA Professional Practice Networks (PPNs) to incorporate the intended goals of the CAP in the day-to-day practice of landscape architecture–especially the Water Conservation PPN.
Water and the Climate Action Plan
Whether used for drinking consumption, water features, or irrigation, moving water by mechanical means consumes energy and historically that energy consumption is associated with carbon emissions. The CAP encourages landscape architects to manage site (non-mechanical) water wisely by planning for extremes, including both flooding and drought, groundwater rise, and increased storm surges. These water concerns could, at least in part, be mitigated by implementing an efficient mechanical water system, such as harvesting and reusing stormwater, greywater, and HVAC condensate for irrigation and other plumbing systems. While encouraging the use of passive irrigation and nature-based water system management, the CAP also suggests avoiding or minimizing irrigation to the greatest extent possible. While the theory is ideal, in practice every project is different and may deliver varying results based on location, plant materials selected, craftsmanship, maintenance, and of course, changing climate.
The CAP aims to increase the percentage of green space in the built environment while eliminating the use of off-site water (such as a municipal domestic water supply or well water). Moreover, off-site water inherently has a certain amount of carbon consumption associated with it in the form of energy consumption for pumping and filtration. However, there are tools available to landscape architects to sustain the planted ecosystem installed on sites to provide positive environmental impacts on a community without foregoing irrigation by keeping water conservation in mind. These tools include only using irrigation to supplement rainfall instead of running all of the time (via weather-sensing smart irrigation controllers), and harvesting alternative water supplies to offset or eliminate potable water demand. The goal should be to create a planting space in which the carbon sequestration ability of the landscape exceeds the carbon impact of the supplemental irrigation demand. A team of knowledgeable irrigation designers and experienced water managers greatly assist in realizing these goals. The Water Conservation PPN is uniquely qualified to lead this conversation and provide landscape architects with the knowledge and tools necessary to both decrease the carbon footprint of our project while maximizing the carbon sequestration ability of a project.
Future Proofing
The CAP is intended to be a living document. As new ideas, technologies, and practices are realized, the plan can adapt and modify to better achieve its vision of a zero emissions promise by the year 2040. But again, this takes teams of talented minds and excited professionals working on individual projects and organizations to make this promise a reality. The Climate Action Committee and subcommittees are only a start. Volunteering for climate action committees or Professional Practice Network leadership gives you the ability to influence the conversation and direction of landscape architecture. Collaboration is the vehicle by which we “future proof” the landscape and communities in which we all live, work, and play.
Bryce Carnehl, Affiliate ASLA, is Specification Marketing Manager at Hunter Industries and an ASLA Water Conservation Professional Practice Network (PPN) leader.
Bryce will be a presenter for Let’s Talk CAP and leading the Water Conservation PPN Meeting with Michael Igo, Affiliate ASLA, PE, LEED AP, at the ASLA 2023 Conference on Landscape Architecture in Minneapolis later this month.
See the ASLA Climate Action Plan and Climate Action Field Guide for more on ASLA’s goals for wise water management and designing with water, including recommendations to:
- Capture, use, and/or harvest all available stormwater and gray water.
- Account for increased water scarcity through landscape-scale catchment, aquifer replenishment, passive irrigation, and nature-based water systems management.
- Irrigation should be avoided or minimized to the greatest extent possible as moving water requires energy. (See SITES Prerequisite 3.1 Manage precipitation on site; Credit 3.3 Manage precipitation beyond baseline.)