Journal: Climate change's effect on the past should be considered, too - WGCU

Journal: Climate change's effect on the past should be considered, too | WGCU PBS & NPR for Southwest Florida

Journal: Climate change's effect on the past should be considered, too

When discussing climate change, the conversation is usually about what’s to come, as in how much seas will rise or how high temperatures will get.

Far less common is what happened yesterday, who lived where, and how climate change will affect the artifacts they left behind.

“And that cultural heritage is potentially under threat as a consequence of climate change, particularly here with respect to sea level rise and storminess,” said Michael Savarese, a Florida Gulf Coast University geology professor and co-author of a study in the journal Historical Archaeology on climate change’s threat to historical sites. “You can't move a Native American midden, pack it up, and move it somewhere else but you could, in effect, invest resources into studying the archeology of that site before it's destroyed."

Given South Florida's rich history, which includes Native American civilizations and Spanish explorers, important artifacts can range from ancient tools to architectural structures to remnants of villages or even garbage piles.

Savarese said due to Southwest Florida's vulnerability to rising sea levels and strong hurricanes there needs to be an added urgency to protect historical artifacts. If they're lost, future generations won't have these tangible pieces of history to learn from.

Saving them, whether that means actually rescuing the artifacts before they disappear or by recording on paper and in photos what the locations looked like, is about respecting the past and ensuring that the stories of those who came before us aren't forgotten.

Modern buildings will be at risk, but so will more than 16,000 archaeological sites that will go underwater. A balance must be found between the past and the future, the authors argue.

Historical sites overlooked

The researchers found that local governments in South Florida are quite focused on climate change when making future land-use plans. But too often, they say, local planners overlook how their ideas could affect important historical sites.

Most marine scientists believe human-caused climate change will alter South Florida's coastline due to sea-level rise alone.

Savarese and his co-authors predict that, in about 15 years, sea level will rise between 10-17 inches. By 2070, it could rise between 21-54 inches. If the sea rises that much Florida will lose 10% of its land in the next 100 years.

That means more flooding, people moving away from the coasts, and now potable water will be undrinkable in the future. More hurricanes and hotter temperatures will make it even harder for people to work outside.

Collier County decides what’s most important to protect differently than Miami-Dade County does. Palm Beach County has a third way of doing it.

While all historical sites are important, some are more significant than others. So when it comes to building things like seawalls to protect against rising seas, hard choices have to be made about what gets saved, and in what format.

“We need to document and prioritize these sites to save their information,” the authors wrote. “Even if we can't save the sites themselves.”

The article looks at how these decisions are made, who's involved, and how the decision-making may be useful for both scientists studying the past and for future building projects.

Everglades rich in human history

Some of those projects will be in the Florida Everglades, where NOAA’s Office of Coastal Management estimates that about four feet of sea level rise will inundate large swaths of the park, which will be underwater during the highest tides by the year 2100.

Sea level rise also will swamp the Ten Thousand Islands Archeological District and the Flamingo District, which is at the lowest tip of mainland Florida. All but the highest cultural sites would be inundated.

For now, there are plenty of sites still intact from a time perhaps 1,500 years ago when Native Americans adapted to the freshwater marsh of the southern Everglades leaving behind trash mounds and shell middens.

“They used hardwood hammocks that rose like islands in the water as a home base for daily activities. As park archeologists excavated sites on the hammocks, it became apparent that Indigenous people had gathered, cleaned, and processed food there, and, more recently, gardened,” wrote April Watson in Park Science magazine last year.

“Indigenous people also constructed a canal — the Mud Lake Canal — that connected the inland Everglades to the ocean. This allowed them to move from the Bear Lake region of the Everglades to Whitewater Bay while avoiding the treacherous waters in Cape Sable.”

The Shark River Slough Archeological District today is mostly a flooded freshwater marsh, with very little inhabitable dry ground, Watson wrote.

“The slough is one of two main routes of water moving through the Everglades. The archeological sites found in the Shark River Slough are black earth middens — accumulations of sediment, peat and muck, shell and bone, and cooking fat and debris. They are akin to refuse piles today. Indigenous people may have used the Shark River Slough to form smaller family camps or to procure resources.”

"Unlike the middens in the Shark River Slough, those in the Ten Thousand Islands region of Southwest Florida were intentionally built. This archeological district is a maze of tiny islands, mangroves, and slow-moving water, with extensive shell middens and shell works from about 1,000 to 1,500 years ago. They have some of the largest and most complex shell constructions in the world. Indigenous people used them as platforms for building homes."- April Watson in Park Science magazine

The park also has structures that date from the 1930s to the 1970s, the earliest being the work of the Civilian Conservation Corps. The remains of corps camps in Royal Palm and Flamingo still exist. The camp buildings in Flamingo were constructed of limestone blocks, which were durable enough to survive even when other parts of the buildings did not make it through a hurricane or flood.

Headway is being made

Savarese’s co-researchers on the journal article published last week, “Act Local: Climate-Change Policy at the County Level in South Florida,” include S. Ayers-Rigsby of Florida Atlantic University, R. Kangas of the University of South Florida, and J. Ransom from Miami-Dade County.

“Archaeologists for years have known climate change will have an increasingly devastating impact on archaeological sites,” the journal authors wrote. “The tedious work of promoting the inclusion of cultural sites in climate-change planning processes continues, and cultural resources are still left out of planning documents.

“However, as archaeologists continue to do this work, more headway is being made.”

Environmental reporting for WGCU is funded in part by VoLo Foundation, a non-profit with a mission to accelerate change and global impact by supporting science-based climate solutions, enhancing education, and improving health.

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