KING COUNTY, Wash. — When temperatures soar, there are some places in western Washington where temperatures can vary by as much as 20 degrees.
Data from a “heat mapping” project in Seattle and King County shows areas with less tree canopy can experience hotter temperatures during extreme heatwaves.
Often, the “heat islands” can disproportionately impact communities of color or low-income residents.
King County is in the midst of an effort to add more green spaces and trees within those spaces to fight back against climate change and dangerous heat waves. King County Parks describes it as a “comprehensive approach to forest health” that could result in the addition and preservation of 3 million trees.
Part of the plan involves acquiring new green spaces like the Glendale Forest
“It's places like this that are going to help keep our temperatures down,” Sarah Brandt with the Environmental Policy and Initiatives Unit said.
The county transformed this patch of land from a regular dump site that struggled with invasive weeds. The weeds were so bad they threatened the health of the trees.
“They were carrying this really heavy loud of English Ivy and blackberry and knotweed - all these plants that are suppressing these native species,” Sasha Shaw with the noxious weed control program said. “So what's going to happen is the forest is on a trajectory toward dying."
The goal is to plant and preserve enough to add those 3 million trees to the county's canopy by 2025.
“We're planting a half million trees but through protection of areas like this we're trying to conserve and protect an additional 2 million trees. So that's about 6,500 acres of forest,” Brandt said.
The work focuses not just on adding trees but making sure they preserve mature trees and vegetation already providing shade and sequestering carbon.
They believe these green spaces could make future heatwaves more manageable. At the Glendale Forest and other sites, they will add trails or other ways to make the green spaces accessible.
“It’s a real benefit for human health to have a space like this available within walking distance,” Brandt said.
This year’s record heat has taken a toll on their work. They would generally start planting their next round of trees in the fall but have pushed it back closer the winter to make sure there will be enough rain to support young trees.
“You have to make sure a space is ready to accept the tree that you plant and that it will stay healthy and you have to take care of that tree over time,” Brandt said.
It is a long-term approach to fight climate change and it will take time to continue finding spaces, restoring them, and seeing results. But county officials believe building a green bridge to those heat islands is critical to wipe them off the map.