## 4 Discussion
The benefits already provided by existing trees in urban communities include approximately $7.8 billion in savings from reduced heating and cooling of residential buildings [40]. In the case of minimal space for tree planting, increasing vegetative cover, such as on roofs, has also been found to aid in cooling [10]. Our study points to the need to concentrate future planting in specific neighborhoods to reduce current inequities in urban heating [37].  
Richmond is one of the cities that would greatly benefit from mass tree planting and other efforts to mitigate heat [41]. In recent planning initiatives, including the Office of Sustainability's RVAgreen 2050 and Richmond's most recent 20-year plan [42], there has been notable attention paid to UHI and climate issues. RVAgreen 2050 is the City of Richmond's \"equity-centered climate action and resilience planning initiative to achieve net zero greenhouse gas emissions by 2050 and help the community adapt to Richmond's climate impacts of extreme heat, precipitation, and flooding\" [43] (paragraph 1). The city plans to address urban heat by using light-colored pavement to reflect sunlight, varying building heights in hot neighborhoods to increase air flow, protecting and restoring natural resources, increasing tree shade on sidewalks, and ensuring that every Richmond resident lives within a ten-minute walk of a park [42]. Though the goal is to implement these improvements throughout the entirety of the city, the main and initial focus will be on the hottest and poorest neighborhoods of Richmond.  
Additional benefits of these proposed improvements to the physical environment include a variety of health benefits. Green urban planning has the potential to reduce mental illness within vulnerable populations [44], who tend to be those living in the hottest areas of the city. These mental health concerns span from everyday stress to more serious psychiatric disorders like schizophrenia. In a study of 943,027 residents of Denmark, [PERSON] et al. [44] found that the risk of developing a psychiatric disorder between adolescence and adulthood was reduced by up to 55% when childhood development took place in a relatively green area. The association between improved mental health and ample green space was still evident when controlling for socio-economic status, urbanization, and family history of mental conditions, all known predictors of psychiatric disorders.  
The hottest areas of the city in our study tend to correspond to historically redlined regions as has been documented for many cities of the U.S. [21]. Church Hill, an area of Richmond located in the northeast part of the city, is one of these regions. The southern part of Church Hill has been gentrified while the north has not. In the 1950s, Broad Streetwas the dividing line between north and south. However, as gentrification spreads north, the present-day border has moved to N Street, which aligns with the census block divide. Yet, we do not yet see differences in temperature among the different neighborhoods in Church Hill, suggesting historical factors continue to have an outsized influence on current temperatures in cities.  
Going forward, it would be beneficial to repeat our data collection to look for any progression or changes within the predictor variables and their relationship to temperature. Performing additional case studies, like the Church Hill analyses, could be useful in evaluating the effects of redlining on other areas known to have experienced gentrification. Further analysis of Scott's Addition would be an interesting extension since the greatest change in educational attainment from 2010 to 2018, our indicator of gentrification, was found here. The area was dominated by industrialization starting in the early 20 th century when the land was annexed to the City of Richmond [45], but has become Richmond's fastest growing neighborhood in recent years [46]. Due to a call for more residential development in the late 20 th century, Scott's Addition now includes a variety of breweries, restaurants, and apartment complexes [45]. Currently, the 6505-strong population of Scott's Addition consists of 87.2% white collar workers and only 12.8% blue collar workers. Households are predominately non-family households without children [47]. As factories made way for new businesses, younger people with more education and higher incomes (average household income: $73,488 [47]) were drawn to the area, contributing to the change in educational attainment over time.