Dr. Robert Knight writes today June 18, 2016 in the Gainesville Sun describing a possible scenario for Florida. Climate change is in the works, just a normal part of the cycle that has been happening for millions of years and will continue to do so (possibly with our help,) in spite of our whining and denying.
Dr. Knight is on the OSFR board of advisors.
Robert Knight: Imagine a future when Florida becomes desert
By Robert Knight
Special to The Sun
Published: Saturday, June 18, 2016 at 6:01 a.m.
Last Modified: Wednesday, June 15, 2016 at 3:02 p.m.
One of my favorite Gary Larson cartoons was titled “Frog Pioneers.” In classic Larson simplicity, the cartoon depicted three frogs with shovels and coonskin hats standing in a cactus- and scorpion-infested desert landscape. The lead frog boldly says, “We’ll put the swamp here!” This cartoon appeals to me because it pokes fun at humans who will stop at nothing to achieve their goal of dominion over the realities of Mother Earth.
Like the Frog Pioneers, north Floridians live in a virtual desert. Lying between 28 and 31 degrees north latitude, the Florida springs region is squarely within the so-called horse latitudes, a geographical belt dominated by a subtropical climate with consistently high atmospheric pressure that suppresses cloud formation and precipitation. Four of the world’s 10 greatest deserts — the Great Basin of North America, the Saharan of Africa and the Arabian and the Thar or Great Indian Desert of Asia — occur in this same latitudinal zone.
The Florida peninsula is essentially an island embedded in a subtropical ocean. As long as summer winds are generally from the west, humid air rises over our state’s heated surface, creating convective rainfall that maintains our green plants and underground aquifers. In the winter months, less predictable frontal events provide periodic precipitation. Seemingly random tropical storms and hurricanes add to our long-term water supply.
But what happens when Mother Nature whimsically decides to station the Bermuda High over or just east of north Florida? Summer rains and tropical storms will steer clear and frontal systems will stay to the north. Rain totals will plummet and our already stressed water supply will be severely depleted. The world’s climate is changing in unpredictable ways. What if Florida is unexpectedly faced with multiple years of extended drought?
During an extended period of low rainfall (e.g., successive annual totals less than 35 inches, compared to the state’s average annual precipitation of about 51 inches) our subtropical heat and abundant vegetation will continue to evaporate and transpire surface and shallow groundwater, leaving no net rainfall, no water to maintain the vegetation and no recharge of our principal water supply — the Floridan Aquifer. The result will be regional aridity at a scale not apparent in the pollen record since the late Pleistocene about 10,000 years ago. At that time, and without the assistance of several million wells currently tapping the Floridan Aquifer, groundwater levels fell, spring and river flows slowed or stopped, and north Florida was a semi-arid grassland reminiscent of the Great Plains of the western U.S. Now, with an annual groundwater extraction averaging more than a trillion gallons, adding a few years of successive droughts may put all of us on an unintentional paleo diet.
Some will think immediately of desalination as the panacea for this possible future. At more than 10 times the cost of extracting water from the aquifer, we can quench our thirsts with de-salted water for a limited time, but there will be no economically-viable way to water crops, livestock or lawns.
The lesson from the real world, including many areas of the American West, is that our unsustainable depletion of the Floridan Aquifer may lead to consequences we can ill afford. We can make a conscious decision to husband our most valuable natural resource, the Floridan Aquifer, so we do not deplete it through our collective greed. Or, like the optimistic Frog Pioneers colonizing a New World, we can continue to dissipate Florida’s natural bounty for a little while longer with no concern for a prosperous future.
— Robert Knight is director of the Howard T. Odum Florida Springs Institute in High Springs.