The third assessment report of the Intergovernmental Panel on Climate Change (IPCC), Climate Change 2022: Mitigation of Climate Change, found that cities' are a major contributor to global emissions.

 
IPCC was created by approximately 300 scientists in 65 countries over the last seven years. Estimate place cities' global emissions share at more than 70 percent. This coupled with expected population growth, existing and future cities can either be the primary source of future warming or a solution.

"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," Torey Carter-Conneen, ASLA CEO explained.

According to the IPCC, if we continue on our current path, future cities will contribute 40 billion metric tons of emissions each year by 2050, but if steps are taken this decade, it could reach as low as 3 billion tons.

The report calls for the preservation of existing ecosystems that store carbon like prairies and wetlands, but also notes that these ecosystems are threatened by rising temperatures, wildfires, and human development.
https://www.asla.org/NewsReleaseDetails.aspx?id=61004