Greenhouse Gas Emissions Data

Overview

Greenhouse gas emissions are the release of gases into the atmosphere that trap heat and contribute to the greenhouse effect. These gases, like carbon dioxide and methane, occur naturally but are also produced by human activities, namely burning fossil fuels. 

How GHG emissions impact St. Louis residents

GHG emissions increase the frequency and severity of climate activity. In St. Louis City, this translates to higher risk of flooding, as well as longer, more intense heat waves. 

These effects have been seen in four of the six hottest years on record occurring in the last decade, and in the severe flooding the city experienced in 2022. The city is also at risk of cold waves, drought and tornadoes, like the one experienced in May 2025. 

These events can cause major property damage, poor health outcomes, and even loss of life. The May 16, 2025, tornado that moved through the city claimed five lives, injured dozens, and is estimated to have caused $1.6 billion in damage, with more than 5,000 impacted buildings. 

Additionally, fossil fuels that contribute to greenhouse gas emissions also emit air pollutants that can cause asthma and other respiratory conditions.

The City of St. Louis’ climate goals

Since 2005, the City of St. Louis has been committed to measuring and reducing the City's GHG emissions. Over time, this commitment has evolved to a citywide target of carbon neutrality by 2050 in alignment with the Global Covenant of Mayors for Climate and Energy and the Paris Agreement. 

Conducting a greenhouse gas emissions inventory is important because one cannot effectively reduce what isn't measured. The City has conducted GHG Emissions Inventories for the years 2005, 2010, 2013, 2015, 2018 and 2023.

Each inventory includes two components:

1. Government Operations: GHG emissions associated with the City's municipal operations.

2. Community: GHG emissions generated across the broader community.

Together, these inventories quantify St. Louis' total contributions to heat-trapping greenhouse gases in the atmosphere.

You can explore the results of these GHG Inventories by changing the year in the upper right corner of the Total GHG Emission dashboard below. 

Total Greenhouse Gas Emissions by Year

In 2023, overall emissions totaled 6,403,616 MT CO2e - a decrease of 5.86% from the previous inventory in 2018, and a 24.4% reduction from the 2005 baseline.

Key drivers for these reductions include:

• A 23% improvement to the regional electrical grid overall due to decommissioning of coal plants and increased renewable energy sources.
• A mild winter in 2023 resulting in decreased demand for natural gas for heating.
• Continued population decrease resulting in a reduction in overall emissions (though per capita emissions slightly increased).
• Efficiency measures, particularly in government buildings and streetlights, as well as the Building Energy Performance Standard (BEPS) introduced in 2020.

Per Capita Emissions

A useful way to put emissions into context is to look at per capita emissions, or emissions per person in St. Louis City. This helps to understand how emissions fluctuate relative to population changes and helps to compare emissions for cities of various sizes.

Per capita emissions have varied over time. In 2023, they increased slightly from 2018 despite population decline. 2023 per capita emissions remain 13% lower than the 2005 baseline. This indicates that reduced emissions are not uniformly tied to a decline in population.

St. Louis City’s per capita emissions are higher than the U.S. 2023 average, which is 17.6 MT CO2 e per person according to the World Resources Institute. 
 

Community Emissions View

Emissions related to buildings, transportation, and waste from residents and businesses decreased 5.3% from the previous inventory in 2018, and have decreased 23.9% from the 2005 baseline.

The majority of the community’s GHG emissions come from buildings and houses, collectively contributing 63% of total community emissions. Transportation is the highest non-building sector, comprising 21%.

Government Emissions View

Emissions from government operations decreased 23.2% from the previous inventory in 2018, and have decreased 39% from the 2005 baseline.

LED replacements for streetlights and traffic signals have been highly effective and contributed to the highest sector reduction from the baseline.

Municipal buildings and facilities remain the top contributor at 30% of government emissions. Water delivery is the next highest emitting category, comprising 27% of the City’s total emissions.