Climate Temperature Barely Budged At Peak of the Leaded Gasoline Era

Steadily increasing global temperatures have been at the heart of the climate change debate. Over the last 40 years, the National Aeronautic and Space Administration (NASA) and others have measured incrementally higher global temperatures each year, which are usually ascribed to growing release of greenhouse gases such as carbon dioxide into the atmosphere.

But prior to that, during the years between 1949 and 1975, the change in temperature was low. At times it was non-existent despite being at the height of gasoline consumption at that time—as well as global population and greenhouse gas emissions.

At certain points during that period from the 50s to the 70s, there were no temperature anomalies. The year 1965 had the same temperature anomaly as a decade prior.

The years between 1949 and 1975 were the height of leaded gasoline consumption. While lead as an additive for gasoline was invented in the twenties to improve engine performance and prevent knocking, it wasn’t until after WW II when high-compression V8 engines were developed that could take advantage of its abilities. Auto sales skyrocketed in the post-war period. Leaded gasoline became the default through the 50s, 60s, and 70s, until lead gasoline additives were phased out in the U.S. starting in 1974.

During that 25 year span of the leaded gasoline era, global temperatures barely changed. NASA data shows a maximum total temperature increase of .11 degrees celsius in the land-ocean temperature index. In the 25 years between 1914 and 1939 the maximum change was .29 degrees, almost 3 times that of the 1949-1975 period. From 1975-2000, the maximum total change was .45 degrees, over 4 times that of the leaded gasoline era. Without that period of flat-lining temperatures, the climate temperature has been steadily growing since 1912.

But as concerns about its health consequences grew, the Environmental Protection Agency (EPA) took notice and began crafting regulations to limit its use. It started with restrictions set in 1973 following the passage of the Clean Air Act in 1970, which would begin to be enforced around 1974-1975.

The widespread production of cars with catalytic converters for improved emissions control in 1975 meant that more cars could not ingest leaded gasoline. The additive could foul the catalytic process. Eventually lead as an additive was banned in the U.S. entirely in 1987 with other countries following suit. Although it is still available in certain countries, like Algeria, Iraq, and Lebanon.

At the same time leaded gasoline was phased out in 1975, global temperatures began to rise again and continued rising up to the current day at a rate similar to that of the pre-leaded gasoline era.

A 2009 Nature Geoscience report from researchers at Pacific Northwest National Laboratory showed that lead in the atmosphere from gasoline could have caused global cooling because of how it helps dust in the atmosphere form ice crystals that can reflect sunlight.

Known Health Issues With Leaded Gasoline

Ever since it was discovered, lead gasoline additives were known to have health concerns. According to a 2005 paper in the journal International Journal of Occupational and Environmental Health, researchers at GM in 1921 knew of other potential fuel additives that could improve fuel efficiency and eliminate knocking, such as benzene and ethyl alcohol, but lead would be more profitable. Soon after, GM would join with Standard Oil, the predecessor to Exxon, and DuPont to form the Ethyl Corporation in 1924 to market leaded gasoline, based on its chemical name—tetraethyl lead.

Throughout the twenties there were reports of deaths in the factories that produced tetraethyl lead. At one point, New Jersey and other states banned leaded additives following an incident at a Standard Oil factory in Bayway, NJ where factory workers were dragged away with fits of madness because of exposure to what was termed “loony gas.” But there was little evidence that immediate exposure could cause such effects.

As criticism of health concerns grew, supporters of lead rallied behind the additive, blaming the deaths on mistakes during production and other issues, focusing on improving factory conditions, and insisting there were no viable alternatives.

Attempts to prove the health concerns of tetraethyl to the general public would prove inconclusive at the time and the bans were lifted.

Eventually, research would refocus on the health effects of lead after it was shown to reduce average mental ability in children from long-term exposure, leading to the phase-down of leaded gasoline in the 70s and eventual E.P.A ban in the 80s.

Exxon First Researched Climate Change As Leaded Gasoline Was Phased Out

Recent documents published by InsideClimate News revealed that the oil giant Exxon researched the potential for climate change and knew about its impacts in 1977, right after the phase-down in leaded gasoline, although representatives for the company have said publicly that their findings at the time were not conclusive.

The risks of climate change were not revealed until the late 80s once leaded gasoline was finally banned by the E.P.A. In June of 1988, NASA scientist James Hansen would testify that the world was already warming, which might not have been as apparent in 1975.

In the late eighties is when Exxon would begin to fund groups like the Global Climate Coalition to discredit the belief that questioned the science behind climate change. While Exxon funded groups to criticize climate change science, heirs to the Rockefeller fortune such as David Kaiser and the Rockefeller Family Fund would support groups and investigations into climate change and how much Exxon knew about its potential risks.

Currently, the climate temperature anomaly stands at 1 degree celsius (1.8 degrees Fahrenheit).