Major errors found in Al Gore-founded Climate TRACE database

Date: June 18, 2026 Source: Northern Arizona University Summary: A new study from Northern Arizona University is raising red flags about a widely used global emissions database from Climate TRACE, a consortium co-founded . Researchers found that the database may be dramatically undercounting carbon dioxide emissions from cars and trucks in cities— 70% across 260 U. S. cities, with some cities showing gaps of more than 90%. Share: Facebook Twitter Pinterest LinkedIN Email FULL STORY Scientists found that a major global emissions database may be dramatically undercounting city vehicle pollution, raising concerns about the accuracy of climate data used by policymakers. Credit: Shutterstock A new study from Northern Arizona University (NAU) suggests that a major global greenhouse gas emissions database may be significantly undercounting carbon dioxide emissions from vehicles in cities. According to the researchers, the Climate TRACE database, developed -founded , underestimates urban vehicle CO2 emissions 70%. The findings were published today in Environmental Research Letters , a professor in NAU's School of Informatics, Computing, and Cyber Systems (SICCS). The study focused on carbon dioxide (CO2) emissions from cars and trucks reported in the recently released Climate TRACE database. Gurney said the results, together with an earlier study that identified similar issues in Climate TRACE estimates for power plants, raise concerns about the reliability of emissions data used to guide climate policy and decision-making. "Given the importance of vehicle CO2 emissions in cities, we carefully examined the Climate TRACE data which relied on promising new artificial intelligence-based approaches," Gurney said. "When combined with our previous study on Climate TRACE power plant CO2 emissions, our results suggest that the Climate TRACE data significantly underestimate over half of U. S. fossil fuel-based CO2 emissions in cities." Comparing Climate TRACE to the Vulcan Emissions Database To evaluate the Climate TRACE estimates, Gurney and his colleagues compared them with data from Vulcan, an "onroad" emissions database developed . The Vulcan system is calibrated using official traffic records and energy consumption data, providing an independent benchmark for measuring vehicle emissions. The researchers compared vehicle CO2 emissions data from 260 U. S. cities across the two databases. "While the Vulcan onroad data is not perfect, with uncertainty of about 14%, this is far lower than the differences found when we compared 260 city vehicle CO2 emissions in the U. S. to the Climate TRACE database," said Bilal Aslam, a SICCS postdoc and co-investigator on the study. "The Climate TRACE CO2 emissions were, on average, 70% lower than those same emissions in the Vulcan onroad CO2 emissions database." According to the researchers, the discrepancies were even larger in some locations. "Individual cities such as Indianapolis and Nashville were lower 90%," added Pawlok Dass, a research associate in SICCS and contributor to the study.