Trees, often towering above us and filled with birds, are frequently overlooked, especially by city dwellers who hurry past without recognizing their crucial roles. These include lowering temperatures, reducing flooding, and providing habitats for wildlife.
City officials also tend to overlook these benefits. While mayors globally commit to lowering municipal greenhouse gas emissions, they often neglect the straightforward solution of enhancing urban forests, argue dozens of scientists in a recent essay. “We have to elevate it from something that is nice to have to something that we require — like, mandatory,” stated Manuel Esperon-Rodriguez, an ecologist at Bangor University in the UK and lead author of the essay, published today in the journal PLOS Climate. “In the same way that we treat education, security, transportation, it has to be elevated to that level.”
Urban forestry holds significant importance because it cools urban areas by providing shade and releasing water vapor. Additionally, green spaces allow stormwater to infiltrate the ground, preventing pooling and flooding, which is crucial as rainfall intensifies with climate change. Visiting parks also enhances mental health, while urban farms offer nutritious food and job opportunities. Planting trees, particularly native species, supports wildlife by offering food and shelter. Vegetation also absorbs pollutants, benefiting air quality for all.
The scientists have outlined a four-step plan for funding, nurturing, and preserving urban forests. This includes individual trees on sidewalks, parks, and city woodlands. It’s about all vegetation — trees and shrubs — within city boundaries, whether in backyards or street medians.
The primary challenge is investment. Urban forestry involves more than just planting trees; it requires resources to maintain them, especially when they’re newly planted and vulnerable to pests. While private funding exists, it’s not always reliable. Therefore, city governments should allocate budgets for green spaces, according to the researchers. “We say that it has to be critical infrastructure, because then we need a special budget dedicated just to them,” Esperon-Rodriguez emphasized.
Even for financially constrained governments, investing in parks and recreation has proven returns. A recent report highlighted that every dollar invested yields $3 in local economic benefits annually. Green spaces promote exercise, boost public health, and reduce sedentary lifestyle costs. They attract both locals and tourists, stimulating economic activity as visitors explore nearby areas for shopping or dining. Thus, while maintaining these green spaces requires funding, it ultimately benefits cities.
The scientists stress the importance of equitable distribution of these green spaces. Wealthier areas tend to be greener and cooler than underserved neighborhoods. Those without air conditioning face greater risks from the urban heat island effect, where buildings and roads absorb heat during the day and release it at night. “Then what’s the cost?” Esperon-Rodriguez asked. “They are missing opportunities, they are missing recreational activities. And if they don’t have air conditioning, then on top of that there is the issue of health.”
Cities should collaborate with local communities to develop strategies for planting trees. Preferences may vary; some residents might prefer fruit trees, while others may have concerns about fallen fruit or allergies and request less pollen-producing trees.
Esperon-Rodriguez suggests that expanding urban canopies should be legally mandated, rather than a campaign promise. This approach is more sustainable and ensures accountability for meeting targets, he stated.
These initiatives must be based on evidence, the essay concludes. Cities need to identify not only preferred tree species but also those capable of surviving rising temperatures. The focus should be on long-term resilience, ensuring today’s plantings endure for decades. “It’s a way to secure,” Esperon-Rodriguez remarked, “that whatever we’re planting today is going to survive the next 10, 20, or 50 years.”
