ASLA urges governments to focus on cities and nature to meet climate goals.
The third assessment report of the Intergovernmental Panel on Climate Change (IPCC) — Climate Change 2022: Mitigation of Climate Change — which was created by nearly 300 scientists in 65 countries over the past seven years, finds that cities are a significant contributor to global emissions.
Recent estimates place cities’ share of global emissions at more than 70 percent. With expected population growth, existing and future cities can either be the primary source of future warming or a key solution.
According to the IPCC, if little is done, future cities could contribute 40 billion metric tons of emissions each year by 2050. But by taking important steps starting this decade, that number could reach as low as 3 billion tons.
“Landscape architects are systems designers. We are already designing the next generation of park, transportation, and water infrastructure needed to make this transformation happen. But we need more policymakers to prioritize these changes,” said ASLA President Jeannie Martin, FASLA.
“Landscape architects plan and design walkable environments that are central to reducing urban energy demand and emissions. This work has involved partnering with planning and design professions to pair public transit with transit-oriented development, and integrate Complete Streets, which offer safe, accessible pedestrian and bicycle access, and trails and greenways,” said Torey Carter-Conneen, ASLA CEO.
Designing with nature is also critical to achieving broader urban climate goals. Landscape architects integrate green infrastructure in the form of parks, green roofs, green streets, rain gardens, and bioswales. As the IPCC notes, these strategies not only sequester carbon but also manage stormwater, reduce urban heat islands, increase biodiversity, and improve health and well-being.
“We design cities to include living systems. Landscape architects store carbon by incorporating diverse ecologies into the urban landscape. This also helps cities become more resilient to climate impacts,” said Scott Bishop, ASLA, Chair of the ASLA Climate Action Committee.
The IPCC’s latest report calls for preserving existing ecosystems outside cities that store carbon as well, such as forests, prairies, peatlands, mangroves, and wetlands. But notes that these ecosystems are also increasingly threatened by rising temperatures, wildfires and other climate impacts, and sprawl.
Renewable energy now powers nearly 40 percent of global electricity, with wind and solar now making up 10 percent of the total. The IPCC report finds that since 2010, the cost of solar panels has decreased by 85 percent and wind turbines by more than 50 percent. Still, governments and companies need to spend an estimated $1.8 to 3.6 trillion each year on renewable power, approximately 3-6 times the current amount, to reach climate goals.
Landscape architects can help plan an expansion of wind and solar across our landscapes in a way that supports ecological restoration and provides greater community benefits.