Some scenes in last week’s news look familiar.
A water reservoir dropping to dangerously low levels. Long-buried carcasses of cars emerging at the bottom.
Graffiti saying “welcome to the desert.” Government officials pointing out the 2015 drought is the worst in many decades.
These scenes aren’t referring to Lake Lanier, or even Georgia. They are playing out in the state and city of São Paulo (pronounced “San Paulo”), Brazil, right now. We like to think of the metro Atlanta area, population 5.6 million, as big.
But it’s dwarfed by São Paulo City, which counts almost four times that many people. Including satellite cities, some estimates range as high as 29 million. Flying into São Paulo conveys a breathtaking view of a seemingly endless sea of high-rise buildings.
Obviously, water demand from this region, one of the world’s most populated, is enormous. In 2014, a drought pattern began and continues today. It has drained the Cantareira reservoir, the city’s main source of water, to less than 6 percent of its capacity. In Rio de Janeiro, the neighboring state and city, the reservoir level is now zero.
It seems ironic that Brazil is also home to the world’s largest reserves of rainforest, which is produced by daily rainstorms. But those rainforests are much closer to the equator than São Paulo and Rio.
Those megacities are near 24 and 23 degrees latitude south. They depend on rain brought from the ocean by winds from a large high-pressure cell, similar to the Bermuda High that sweeps moisture into Georgia.
But in the U.S. Southeast, we have the advantage of the Gulf of Mexico, which also supplies rain when the wind is from the southwest. A southwesterly wind in southern Brazil, on the other hand, brings air from landlocked Paraguay and the dry plains of Argentina.
With rainfall totals that have reached only one-third of normal levels this year, and summer season at its peak now, São Paulo is learning the painful lessons North Georgia has also experienced. Residents of the megacity are collecting water in tanks because municipal supplies fail on a regular basis. Politicians are urging conservation.
The news from the Southern Hemisphere is a dire warning that our region, too, needs to be mindful of its water consumption because drought will return to Georgia, as well.
Rudi Kiefer, Ph.D., is a professor of physical science and director of sustainability at Brenau University. His column appears Sundays and at gainesvilletimes.com.