Anyone concerned with climate change in Florida probably has their eyes fixated on the coasts, as rising seas nip away at our beaches and bays. But, to get a true feel of how bad things could someday get, maybe we should cast our gaze inland.
Take a look on a satellite map, and the Lake Wales Ridge stands out as a sandy spine running through the middle of the state. From Clermont in the north, south almost to Lake Okeechobee, rolling hills give this a very un-Florida feel.
Parts of the Ridge – especially in the rural southern reaches – have some of the highest concentrations of plants and animals found nowhere else in the world.
That’s because, a million or two years ago, the tops of these low-rising peaks were the only parts of Florida above water.
“This is probably, in terms of climate change, the safest place to be in Florida. It’s not been under the ocean for two million years, it’s not likely to be under the ocean for that long, as well,” says biologist Reed Bowman.
Bowman is in his front office – an SUV bumping along the sandy roads that bisect the Archbold Biological Station. It’s a rare expanse of Florida scrub, with endless vistas from atop its gentle rises. Not a building intrudes on this bucolic scene. The closest town is a crossroads called Venus. It’s got about 850 people.
Archbold was established in 1941, a gift from the grandson of the man who built the Brooklyn Bridge.
It’s not like the Ridge will succumb to the waves again anytime soon. That would probably take the melting of the entire ice caps covering Greenland and Antarctica. But the history of the Ridge is a cautionary tale of, as global warming heats up, what we once were and what we could become again.
“It could certainly happen again, whether it’s anthropogenic climate change, or whether it’s natural climate change,” he said. “But of course the time frame would be millions and millions of years. But you could take that as an analogue. You could see severe consequences of that. We could see similar consequences with just little bits of sea level rise. Not so much that we’re going to displace animals, but we are going to displace humans.”
Florida’s coastlines have ebbed and flowed over the millennia. A map created by the University of South Florida’s Libraries and School of Geosciences (shown above) reveals only the high Ridge and the northern extreme of the state bordering Georgia and Alabama as above water during the last extreme event of global warming, about 125,000 years ago.
And the state bulged out 150 miles into the shallow Gulf of Mexico during the last ice age, when water levels were much lower.
Petroniu Bogdan Onac is a professor of biology at the University of South Florida, who has been researching historic sea level rise in both Florida and the Mediterranean.
He says with the exception of the Lake Wales Ridge and areas around Ocala and the northern edge of the state, Florida was underwater completely under water between two and three and a half million years ago.
As recently as 20,000 years ago – before the generally-accepted time that humans first arrived in North America – Onac says the seas were 100 meters (about 330 feet) below the current level. This would put Florida’s west coast from 100 to 150 miles offshore.
“At that time, most of that water was held into the big ice sheets, which entirely covered Canada and most of northern North America,” he said. “Each time there was a glaciation and the ice was up, then the sea was going down. Then, when the climate came back to what we call ‘interglacial’ when it was warmer, the ice melted, and it came back to high levels. Some 125,000, 126,000 years ago, it was 5 to 6 meters (16 to 20 feet) above present day.”
Even though this ebb and flow is natural, Onac says human-created record-high carbon emissions are now forcing the hand of nature.
“If it were only nature, then we should expect to see a kind of cycle, where we could predict where it’s going,” he said of sea level rise. “But the problem here is we are witnessing – since the tide gauges came on board since 1850s in some of the countries in Europe – is we’re seeing that it was slowly increasing, and then there is the effect of the big ice sheets melting, and since 1980 on, it’s accelerated, and since it’s accelerating so much, it’s rising and rising.
“This cycling that we’re expecting is not entirely natural,” Onac said. “Three million, 3 1/2 million years ago, it changed during the earth’s evolution. The only change is we’re forcing the evolution now.”
On top of that, he noted Florida’s flat topography means storm surge – as well as hurricane surge – will mean a lot of salt water intrusion could start impacting the state’s underground freshwater aquifer.
Back on the Lake Wales Ridge, Bowman stands on the most ancient part of Florida – and one of it’s most threatened.
The endangered Florida scrub jay has made a stand here. It’s the only species of bird endemic to Florida – and one of only 15 species found solely in the continental U.S.
Bowman has tamed one of them. A scrub jay lands on a visitor’s head, giving an unexpected scalp massage. The lure – bird feed Bowman carries around with him.
“We are seeing some directional changes. For example, the birds I study, Florida scrub jays, have begun nesting earlier and earlier every year,” he said. “We don’t know whether that’s driven by climate change, but we suspect so. And we don’t yet know what the consequences of that is. Is it hurting the jays, or are they just adapting to the different climate?”
So as the climate warms and rains get either more virulent or more scarce, the effects it will have on places like these are still anyone’s guess. But Bowman says we’re already seeing changes.
“I mean as more and more people suffer the effects of climate change, close to the coasts, there’s going to be an inward migration of people into high ridges like the Lake Wales Ridge,” Bowman said. “And that, I think, is already occuring. And that puts more pressure on all of our natural systems. And I think that’s being driven in large part by climate change.”
Bowman says, like in previous epochs of climate change, animals have to shift where they live and where they eat. But because their habitat is now cut up by development and groves, he says the consequences of this climate change are going to be quite different than any other period in the Earth’s history.
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