Mario Molina

Mario Molina was a Mexican chemist whose pioneering research into the threat of chlorofluorocarbons (CFCs) to the Earth's ozone layer was instrumental in shaping global environmental policy. He shared the Nobel Prize in Chemistry in 1995 with his colleague F. Sherwood Rowland and the Dutch chemist Paul J. Crutzen for their work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone. His scientific advocacy directly led to the international treaty known as the Montreal Protocol, which phased out the production of numerous substances responsible for ozone depletion. Molina remained a leading voice on environmental issues, holding prestigious academic positions and advising governments, including serving on the President's Council of Advisors on Science and Technology for Barack Obama.

Early life and education

Born in Mexico City, he was the son of Roberto Molina Pasquel, a lawyer and diplomat who served as ambassador to Ethiopia, the Philippines, and Australia. From a young age, he was fascinated by science, converting a bathroom into a makeshift laboratory and using a toy microscope given by his aunt. He attended boarding school in Switzerland at the age of 11 before returning to Mexico for his university studies. He earned a bachelor's degree in chemical engineering from the National Autonomous University of Mexico (UNAM) in 1965. Pursuing further studies in polymer chemistry, he received a postgraduate degree from the University of Freiburg in West Germany in 1967. He then moved to the United States, completing his PhD in physical chemistry at the University of California, Berkeley in 1972 under the supervision of George C. Pimentel.

Scientific career and research

After his doctorate, he conducted postdoctoral research at the University of California, Irvine, joining the laboratory of F. Sherwood Rowland. It was at UC Irvine that he began the fateful research into the atmospheric fate of industrially produced chlorofluorocarbons, which were widely used in aerosol spray cans, refrigeration, and air conditioning. His early career included faculty positions at UC Irvine and later at the Jet Propulsion Laboratory (JPL) at the California Institute of Technology. In 1989, he moved to the Massachusetts Institute of Technology (MIT), where he held a joint appointment in the Department of Earth, Atmospheric and Planetary Sciences and the Department of Chemistry for nearly two decades. His research portfolio expanded to include the chemistry of air pollution in the lower atmosphere, particularly in large urban areas like Mexico City.

Ozone depletion discovery and advocacy

In 1974, Molina and Rowland published a seminal paper in the journal *Nature* proposing that inert CFCs could migrate to the stratosphere, where ultraviolet radiation would break them apart, releasing chlorine atoms. They theorized that these chlorine atoms would catalytically destroy ozone molecules, leading to significant depletion of the protective ozone layer and increased ultraviolet radiation reaching the Earth's surface. This hypothesis, initially met with skepticism from industry, was later confirmed by observations, most notably the discovery of the Antarctic ozone hole by British Antarctic Survey scientists in 1985. Molina became a key scientific communicator, testifying before the United States Congress and advising policymakers worldwide. His relentless advocacy was crucial in forging the consensus that led to the adoption of the Montreal Protocol in 1987, a landmark international environmental agreement.

Awards and honors

His groundbreaking work earned him numerous prestigious accolades. The pinnacle was sharing the Nobel Prize in Chemistry in 1995 with Rowland and Crutzen. He was elected to the United States National Academy of Sciences and the Pontifical Academy of Sciences. Other significant honors include the Tyler Prize for Environmental Achievement, the NASA Distinguished Public Service Medal, and the Wolf Prize in Chemistry. In 2013, President Barack Obama awarded him the Presidential Medal of Freedom, the United States' highest civilian honor. He also received the Willard Gibbs Award from the American Chemical Society and was a member of the Institute of Medicine.

Later life and legacy

In 2004, he returned to his home country, establishing and leading the Mario Molina Center for Strategic Studies in Energy and the Environment in Mexico City, a research and policy institute. He also held professorships at UNAM and the University of California, San Diego. He served as a scientific advisor to several Mexican presidents and was a founding member of the Pontifical Academy of Sciences' working group that contributed to Pope Francis's encyclical *Laudato si'*. He passed away in 2020. His legacy endures as one of the most impactful environmental scientists of the 20th century, whose specific research directly led to a successful global regulatory action, safeguarding the ozone layer and serving as a model for international cooperation on climate change.

Category:Mexican chemists Category:Nobel laureates in Chemistry Category:Atmospheric chemists