Chief among our environmental concerns is the impact of human actions and choices on the atmosphere. With the emergence of the industrial age, human activity began to release increasing amounts of pollutants, carbon dioxide and other harmful gases into the atmosphere, largely through burning fossil fuels and deforestation. The elevated levels of harmful gases and pollutants create two key concerns: compromised local air quality and a global “greenhouse” effect that has resulted in changing the Earth’s atmosphere.

Air quality in San Antonio has been steadily getting worse for several years, climbing to 81 parts per billion in 2013 from the baseline of 75 parts per billion in 2010. This number declined slightly in 2014 to 80 parts per billion, but we are still significantly off target from our goal of 68 parts per billion by 2020. To comply with federal policy on air quality, which was put in place to protect the environment and community health, we must be more proactive about local solutions and incentives to improve air quality.

The Air We Breathe

Transportation-related pollutants such as ozone, sulfur dioxide and small particulate matter (PM10 and PM2.5) are the largest contributors to poor air quality in most cities. Many of these transportation-related pollutants are respiratory irritants, a major contributing factor to asthma rates. They are also associated with higher incidence and severity of other respiratory symptoms, impaired lung function and other health problems. Air pollution is significantly worse near energy-intensive industrial areas, diesel truck routes, rail yards, ports and busy/congested roadways.

Good air quality in San Antonio contributes to good health, which benefits families and businesses (in terms of fewer sick days). While air quality is a regional issue addressed by State and regional regulatory agencies, the City has an obligation to contribute to regional efforts to improve air quality. The City’s Air Pollution Program monitors the ambient air in San Antonio and we maintain and enforce a pollution control ordinance. The program monitors for particulate matter 2.5 microns in size (PM2.5) and particulate matter 10 microns in size (PM10). These small particles could cause respiratory problems for small children, the elderly and the general public. The program also operates and maintains an ozone monitor located at Calaveras Lake for the Texas Commission on Environmental Quality (TCEQ).

How we design the built environment can have a significant effect on our air quality. Since motor vehicles are a major air pollution source, urban designs that decrease private automobile use could improve air quality and decrease air pollution related health risks. The City’s plans to meet and exceed state and federal air quality standards rely on control measures that reduce emissions associated with transportation facilities.

These measures include any program to reduce vehicle trips and miles traveled, to increase average vehicle ridership, or to reduce direct emissions from vehicle activity. San Antonio’s sustainability planning work has also included considerations of its transportation and land use networks. The challenge moving forward is to persuade San Antonio residents to drive less. To do that, we must change the way we plan, develop and manage our communities to make it easier and more attractive for people to use transit, bicycle or walk.

Urban Forest and Tree Canopy Preservation: Baltimore, Maryland

Urban areas are subject to much higher rates of pollution and poorer air quality than rural areas, threatening the health of residents. To mitigate the effects of air pollution, the Baltimore, MD has heavily invested in and set an ambitious goal of 40% for Tree Canopy coverage over the city. The Baltimore Metropolitan Area has about 2.8 million trees, but about one-fourth of the city’s trees are distressed, dead or dying. To reach its goal, Baltimore must plant approximately 750,000 trees — about 25,000 to 30,000 each year. Currently, about 7,500 are planted per year. Spearheading these planting goals is a coordinated effort between the City and nonprofit organizations. TreeBaltimore, a city-led partnership funded in part by corporate donations, was established in 2007 and is headed by the Baltimore City Department of Recreation and Parks Forestry Division. TreeBaltimore serves as the umbrella organization for all City agencies and private organizations working to increase the tree canopy of Baltimore. To achieve the 40% goal, it offers free one-gallon trees for homes and businesses every Spring and Fall, fosters community engagement and public education programs and invests in restoration of the existing tree canopy. Baltimore’s commitment to its tree canopy will create a more sustainable and healthy future for all its current and future residents.