If you’ve ever had the good fortune to read one of Dr. Seuss’s whimsical books, you’ll recognize a famous quote from The Lorax, which goes, “I speak for the trees. I speak for the trees, for they have no tongues.”  If the Lorax had a real-life counterpart, it might just be your neighborhood-friendly landscape architect. And while they might not manifest out of tree trunks, speak in rhymes, or spend their days defending the Truffula Tree, many landscape architects abide by the same ethos: they value and appreciate the power of trees to transform places. 

So, why do landscape architects love trees so much? When a landscape architect ‘speaks up’ for trees as a part of their design, it goes beyond the role they play in establishing the aesthetics and character of a landscape – advocating for trees as part of the design is one of the most critical (and simple) pieces of arsenal in our toolkit to help combat a pressing climate change issue facing communities everywhere: rising temperatures and the effects of heat islands.

A heat island (also referred to as an Urban Heat Island or UHI) is an area, typically in urban and built-up environments, that experiences significantly higher temperatures than its surrounding natural, rural areas.

This temperature difference (sometimes as much as 7°F warmer!) is the result of a high concentration of buildings, impervious infrastructure (e.g., roads, sidewalks, parking lots, etc.), and other heat-absorbing materials that retain heat during the day and release it slowly at night.

Additional factors, such as a scarcity of green spaces, limited shade, and human activities like transportation and energy use, also exacerbate a temperature rise (see EPA).

Consequently, heat islands can have major implications for things like: 

• Heightened health risks (i.e., heatstroke + heat exhaustion)
• Poorer air quality (i.e,. smog + respiratory issues)
• Increased climate inequities (i.e., disproportionate impact on vulnerable communities) 
• Diminished comfort + livability (i.e,. uncomfortable or unusable outdoor spaces)
• Higher energy demands + costs (i.e,. increased air conditioning use, electricity demands, higher utility bills, etc.)

As a discipline that is tasked with balancing the needs of people and the natural environment, we rally around the adoption of trees in our designs because we understand the vital conduit they play as an essential, multifunctional tool that helps cultivate much cooler, cleaner, greener, and liveable environments by:

• Providing shade and refuge to much-needed areas that people use every day, like sidewalks, roads, parking lots, buildings, and public spaces 
• Acting as natural air conditioners through evapotranspiration, and
• Sequestering carbon dioxide from the atmosphere, reducing greenhouse gases

When trees are used as part of a larger strategy to help combat the effects of heat islands, it is one simple act of resistance that helps communities adapt and build resilience in the face of climate change. Beyond the use of trees, here are just a few additional ways that landscape architects can help mobilize design interventions to help fight heat islands and champion climate-responsive places:

• Propose planting palettes that are aesthetic and functional, adapt well to the site, and are resilient in changing climate conditions.
• Help reduce pavement and increase green infrastructure, and/or explore nature-based alternatives.
• Understand and analyze human behavior in relation to outdoor spaces and how this can inform strategic tree and/or green space planning
• Explore non-traditional space typologies to increase the availability of green space (e.g., vacant lots, alleyways, street edges, leftover/ interstitial spaces, urban voids, etc.)
• Translating technical/scientific/creative knowledge or language for stakeholders in a way that is accessible, engaging, and easy to digest to make informed and educated decisions about each design effort