EPA tracks total U.S. emissions by publishing the Inventory of U.S. Greenhouse Gas Emissions and Sinks. This annual report estimates the total national greenhouse gas emissions and removals associated with human activities across the United States by source, gas, and economic sector.
Greenhouse gas emissions (GHG emissions) from human activities intensify the greenhouse effect which contributes to climate change. Carbon dioxide (CO 2) from burning fossil fuels (such as coal, oil, and natural gas) is the main cause of climate change.
Requirements may vary depending on the vehicle type, model year, fuel type, and vehicle weight. To save time, if you need an emissions test, complete it before you visit an MVD office. Does My Vehicle Need Emissions Testing? View Emissions Testing Areas Map.
This page is just one in our collection of work on CO2 and Greenhouse Gas Emissions where you can explore emissions of other greenhouse gases; where our emissions come from; what trajectories of future emissions look like; and what is driving emissions across the world.
UNEP’s Emissions Gap Report 2025: Off Target finds that available new climate pledges under the Paris Agreement have only slightly lowered global temperature rise over the course of this century, leaving the world heading for a serious escalation of climate risks and damages.
Global growth in energy-related CO2 emissions slowed in 2025, rising by around 0.4%, the slowest rate since 2021. Despite this slowdown, total energy-related CO2 emissions increased by around 145 million tonnes (Mt) in 2025, reaching a new high of nearly 38.4 billion tonnes (Gt) 1, and 5% above 2019 levels. The increase coincided with record atmospheric CO2 concentrations of about 427 parts ...