It’s hot in San Antonio — and it’s getting hotter.
Extreme heat is a health hazard, especially for the city’s most vulnerable residents. By the time this column appears, San Antonio will have recorded its 40th day of 100 degrees or more, according to National Weather Service data. It feels even hotter for good reason.
The world is on a path to record its hottest year ever, according to the UK-based Carbon Brief, and San Antonio is no exception. If this isn’t the city’s hottest year ever, it will rank among the most oppressive. The record, by the way, is 59 days of 100 degrees or more, set in 2009. Look for that record to be broken this month..
Adding to that fact is the so-called urban heat island effect, increasingly cited by federal officials, public health officials and meteorologists, making the real temperature in cities even higher. Human activity, vehicle emissions and the built environment — the density of tall buildings, impermeable cover like streets, parking lots and other infrastructure — explains why it’s hotter in cities. The scarcity of green spaces and tree canopy also contributes to more oppressive conditions than those experienced outside the metro areas.
Cities mostly trap and re-emit heat rather than reflect it, contributing to the intense discomfort that not only is felt on the skin, but also as we breathe the overheated air, which combines with atmospheric contaminants to increase vulnerable people’s susceptibility to respiratory illnesses.
San Antonio is one of the country’s 10 worst cities for the heat island effect, according to a report released last week by the nonprofit Climate Central. On average, the report states, the hottest summer days in much of San Antonio are 6.9 degrees hotter than the officially recorded temperature. Dallas, Houston and Austin are the other three Texas cities on the list.
Heat is often called the “silent killer,” but the federal government does not consider extreme heat waves afflicting cities as a natural disaster, even though the Environmental Protection Agency now reports on “heat inequity.” The measure recognizes the continuing negative effects of redlining, the federal government’s early 20th century policy of labeling inner city neighborhoods home to Black and Hispanic residents as marginal in value and generally not worthy of investment.
Even today, those neighborhoods in San Antonio and other cities in the South and Southwest often have the fewest sidewalks, the least tree canopy and the most homes without functioning air conditioning. Mass transit is more commonly used by residents in these neighborhoods, where bus stops often do not include shade structures and public water fountains are scarce.
Mayor Ron Nirenberg and Phoenix Mayor Kate Gallego were invited to participate virtually at a White House event last week titled Combatting the Climate Crisis, during which President Biden cited “the existential threat of climate change” to the country. Biden cited one recent summer day in San Antonio when the heat island effect in San Antonio reached “a record 117 degrees.” He condemned states like Texas that have passed laws preventing municipalities from mandating water breaks for outdoor workers, calling such opposition “inhumane.”
Nirenberg said the city’s planned measures to reduce San Antonio’s heat island index include eliminating coal from the CPS Energy electrical generation portfolio and launching the city’s first rapid transit bus line, steps that are four years away at best.
“San Antonio is certainly grateful for a president willing to tackle the current crisis in an equitable manner,” Nirenberg told Biden and other administration officials attending the event.
Biden promised additional climate mitigation spending over and above the 2021 Infrastructure Investment and Jobs Act, but Congressional Democrats and the United States Conference of Mayors have sent letters to the White House calling current measures inadequate. Democrats and city leaders want the Federal Emergency Management Agency (FEMA) to declare states of emergency for cities experiencing sustained extreme heat events, similar to such FEMA declarations when hurricanes, wildfires and other events hit states and cities. Biden is said to resist that proposed change in law.
San Antonio’s most practical option is to increase the planting of trees to improve its tree canopy. The best time to plant a tree, arborists will tell you, is 20 years ago. The second best time is now. The establishment of a new Arboretum project near Brooks is the kind of measure that can make a difference. The San Antonio River Improvement Project, which led to the creation of the Mission Reach and the Howard Peak Greenway Trails system, the city’s two biggest green space and climate mitigation projects in recent decades. Civic Park in Hemisfair when it opens in September will be another.
Yet much more needs to be done. Reducing single-occupant vehicle traffic and improving mass transit, pedestrian and cycling infrastructure are other practical measures cities can take.
Dallas is among five U.S. cities engaged in a three-year project that aims to scale up “smart surfaces” in the city: cool roofs often painted white that reflect heat, green roofs that include actual native plantings and trees, porous pavement, and greater tree cover.
For those of us who can venture out early in the morning or late in the evening with our pets, and otherwise retreat to the comfort of central air conditioning, the extreme heat is something we can ride out in safe shelter.
Hundreds of our fellow San Antonians do not have that option. This is an urgent problem requiring everyone to act, not only our elected leaders.
This column has been updated to correct the number of days reaching 100 degrees or more.
