Greenhouse gas emissions released into San Antonio’s atmosphere dropped slightly between 2019 and 2021, according to new city data, but the rate of reduction is not enough to meet its future climate plan goals, a city executive said Wednesday.

Greenhouse gases, according to the city’s Office of Sustainability, dropped 3.46% between 2019 and 2021, continuing a downward trajectory that began in 2013.

Chief Sustainability Officer Doug Melnick said the drop is a step in the right direction, but the city will have to “be more aggressive” to meet its 2030 goal of reducing local greenhouse gas emissions by 10 million metric tons per year, or a 38% decrease by 2030.

A graph shows the greenhouse gas emission trends in San Antonio.
This graph from the city’s Office of Sustainability shows greenhouse gas emissions trends in San Antonio. Credit: Courtesy / City of San Antonio

Greenhouse gases from human activities are the leading cause of global warming; the gasses act like glass, trapping the sun’s heat near the earth’s surface.

One of the goals of the city’s Climate Ready Climate Action and Adaptation Plan, which was adopted in 2019, is to become carbon neutral — that is, ensure city operations do not result in a net increase in carbon emissions — by 2050.

Reaching the 2030 goal “equates to about a 5% reduction [of greenhouse gases] a year,” he told the council members who sit on the Community Health, Environment, and Culture Committee Thursday. “We really need to figure out what are the incentives, policies and programs — how do we start getting people to make the commitment to make the changes?”

The climate plan includes dozens of strategies to help the city adapt to life in a warmer world. Many are already underway, including creating more green space, preparing for wildfire and incorporating more realistic flooding standards into the city’s drainage codes.

But just months after a draft of the plan was first issued, pushback from businesses softened the one most controversial parts of the plan, and specific commitments to cut emissions were removed.

The plan as adopted calls for actions that will both mitigate climate change by reducing emissions as well as adapt to the changes San Antonio is already experiencing, like hotter summers, more severe droughts and increased risk of flood and wildfires.

The greenhouse gas inventory includes a breakout of various sectors and their emissions. The industrial energy sector, for example, which includes cement plant and manufacturing, saw an almost 18% drop in emissions; vehicle emissions decreased by almost 6% during the study period.

“We don’t know if it’s related to the economic downturn, or to COVID, or something else,” Melnick said.

AACOG data from the spring of 2020, when vehicle traffic plummeted due to the COVID-19 lockdowns, shows emissions from nitrogen oxide — a type of greenhouse gas — were down significantly during this time due to reduced traffic.

A graph shows the San Antonio community greenhouse gas inventory emissions per capita.
While San Antonio’s population increased by more than 7% from 2019 to 2021, per capita emissions fell by almost 11% during the same period, according to city data. Credit: Courtesy / City of San Antonio

Yet while vehicle emissions dropped, emissions from city-owned buildings and facilities increased by 19%, Melnick said. He said the city will need to see how and where it can decrease its own emissions, which represent 1.8% of all community emissions. Residential and commercial energy emissions were also both up, by almost 7% each.

Reducing emissions across the city at a faster rate will require greater community awareness and effective city and utility programs, Melnick said.

“The good news is there’s federal funding,” he said. “We’ve got the new sustainability, energy efficiency and resiliency fund; CPS [Energy] is working on these goals — so there’s lots of good stuff going on.”

Adding more solar power to city buildings, greening bond projects and making electric vehicles more accessible are all on the Office of Sustainability’s to-do list, Melnick said.

“The other huge thing that’s going to help us move the needle is the adoption of the 2022 International Energy Conservation Code, which is the document that guides how we build residential and commercial buildings,” he said. “Those codes are anywhere from 5% to 10% more energy efficient than the previous code.”

Ana Sandoval (D7), in her last meeting as chairwoman of the committee, asked Melnick if the sustainability office could measure how much each city and CPS Energy program reduces greenhouse gases, to better understand their effectiveness.

Melnick said the office would do so.

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Lindsey Carnett

Lindsey Carnett covers the environment, science and utilities for the San Antonio Report.