While individual vehicle emissions have decreased on a per-mile basis over the past decade, shifts in consumer habits are pressuring CO2 production upward, an upcoming publication says.
The growth in the SUV sector has made them the second-largest contributor to increasing CO2 emissions over the past ten years, contributing more than heavy industry (including iron & steel, cement, aluminium), trucking, aviation and shipping, the summary says.
This summary was released ahead of the forthcoming 2019 edition of the World Energy Outlook report, and it challenges widespread notions about the sources of pollution and greenhouse gases in the wake of decades of regulation targeting personal vehicles.
Many who feel cars are being unfairly targeted by green initiatives and regulations often point to overseas shipping and aviation as the primary polluters in the transportation sector, but in terms of CO2, they, along with heavy industry sources, have contributed far less to the increase in global CO2 output than passenger SUVs.
The report breaks out SUV contributions deliberately as a counterpoint to the progress being made in the broader passenger car sector, where the net contribution to CO2 output has been negative over the same time period. The authors explain:
"On average, SUVs consume about a quarter more energy than medium-size cars. As a result, global fuel economy worsened caused in part by the rising SUV demand since the beginning of the decade, even though efficiency improvements in smaller cars saved over 2 million barrels a day, and electric cars displaced less than 100,000 barrels a day."
These trends are born out by data aggregated by Boston University and the New York Times. Their tracking of U.S. CO2 emissions over the past decades illustrates the vast increase in carbon emissions across the United States over the past few decades, despite vast improvements in individual vehicle efficiencies.
The overwhelming contributions from the energy sector also highlight another critical aspect of controlling CO2 output: the energy being used to power electric vehicles will be a critical component of their ultimate carbon footprint, and one some organizations in Europe believe could wash out the gains realized in the automotive sector.