LOS ANGELES — It was dicey being Jewish in a Russia that was tolerant of pogroms, and then came the threat of conscription into the 1904-05 Russo-Japanese War, so one of Mayor Eric Garcetti’s great-grandfathers headed West to America. Another Garcetti great-grandfather married a Mexican woman who, fleeing revolutionary ferment there, headed north to America. Which is why Garcetti, a fourth-generation resident of the world’s most polyglot city, is as American as a kosher burrito, a delicacy available at Mexikosher on Pico Boulevard.
This is a problem the world thought it had fixed. Scientists discovered in the 1980s that chlorofluorocarbons — used for refrigeration and in aerosol sprays — were creating a hole in the stratospheric ozone layer far above Antarctica, which could have devastating consequences for life on Earth. (Ozone absorbs much of the sun’s cancer-causing and DNA-altering ultraviolet rays, keeping them from reaching the planet’s surface.) So the world’s nations came together in Montreal and agreed in 1987 to ban specific chemicals that damage atmospheric ozone. In the years since, the ozone hole has been slowly healing.