Google Doodle celebrates Mario Molina, scientist who uncovered the ozone threat

For years, the chemicals used in hairspray and refrigerators have devastated the ozone layer, which protects us from the sun’s harmful UV rays. But it wasn’t until 1974 that people started to take notice.

That was the year that Mexican scientist Mario Molina published research showing that chlorofluorocarbons — widely used in refrigerator coolants, spray paint, spray deodorant and other aerosol products — deplete the ozone layer. The consequences were devastating, because without the ozone layer that protects us from the sun, our planet would not be habitable. His research helped transform global environmental policy.

To honor Molina’s groundbreaking efforts to combat an environmental disaster, Google dedicated its Doodle to Molina on the Nobel laureate’s 80th birthday.

Born on March 19, 1943 in Mexico City, Molina was drawn to science from an early age. He turned a bathroom in his home into a makeshift lab for his chemistry kits.

“Even before I graduated from high school, I was fascinated by science,” Molina wrote in a biography on the Nobel site. “I still remember my excitement when I first looked at parameciums and amoebas through a rather primitive toy microscope.”

After being sent to a Swiss boarding school at the age of 11, Molina returned to Mexico to study chemical engineering at the National Autonomous University of Mexico before earning a PhD in physical chemistry from the University of California, Berkeley in 1972.

A year later, Molina, working with F. Sherwood Rowland of the University of California, Irvine, found that CFCs can be broken down in the upper atmosphere by ultraviolet radiation, releasing chlorine atoms that destroy ozone molecules. Their findings were published in the journal Nature in 1974.

Their findings have been denounced by industries that rely on CFCs, with one company executive claiming that the pair’s theory was “managed by the KGB’s Ministry of Disinformation”. But in 1985, British researchers discovered a huge hole in the ozone layer over Antarctica.

These findings prompted governments around the world to band together and sign a treaty called the Montreal Protocol in the 1980s to phase out the use of ozone-depleting substances. Science magazine called the agreement “the most successful international effort to combat climate change and environmental degradation.”

For their work, Molina and Rowland shared the 1995 Nobel Prize in Chemistry with Paul J. Crutzen of the Max Planck Institute in Germany. Announcing the award, the Royal Swedish Academy of Sciences said: “The three researchers have contributed to our rescue from a global environmental problem that could have catastrophic consequences.”

In 2013, President Barack Obama awarded Molina the Presidential Medal of Freedom, the highest civilian honor in the United States.

Molina died of a heart attack in 2020 at the age of 77.