Water, water everywhere ... maybe

SOUTH PADRE ISLAND — Some scientists say that over the next 100 years, seas heated by global warming could rise by a foot and a half to 3 feet and possibly devastate America’s coastal communities — including South Padre Island.

Yet representatives from local government and the scientific community are not without hope that areas like this barrier island can respond to challenges posed by global warming.

As scientists and federal officials met this past week in Washington to discuss the threats of global warming this century, an interactive online map from scientists at the University of Arizona showed how the Gulf of Mexico could swallow South Padre Island with a rise of just 3 feet.

Based on U.S. Geological Survey data, the model also illustrates the potential flooding and loss of Boca Chica Beach and areas of Port Isabel, Laguna Vista and land along the Brownsville Ship Channel between the Laguna Madre and Brownsville.

South Padre Island experienced a sudden sea rise of 3 feet in September 2005, when Hurricane Rita hit the Texas and Louisiana coast and created swells at the Island that raised the tides by 3 feet, according to the National Weather Service in Brownsville.

The sea rise flooded some bayside bars and overcame dunes along the beach, flooding businesses, backyards, swimming pools and pouring water and sand onto Gulf Boulevard. Within a matter of hours, the seas rose and hit a peak in the middle of the night and then receded.

During that high water period, the Island’s beach nourishment program, which had previously outpaced erosion, was set back by a matter of years, said Richard Franke, president of the SPI Economic Development Corporation.

The temporary 3-foot sea level increase from Rita also flooded portions of Highway 100 north of town, leaving some football field-sized areas in the county parks that were filled with towering dunes as level as playing fields.

The University of Arizona model suggests the possibility for a similar but gradual sea level rise over the course of 100 years — giving the local community time to prepare to incremental changes.

Expressing doubt

And some officials maintain the sea level rise will not be as severe as 3 feet.

“The road for Highway 100 is only in some cases 4 feet above sea level and in other cases it’s probably 5 feet above mean sea level,” Franke said. “If (seas) rose 3 feet, much of the island would be covered with water unless it was elevated. So that doesn’t quite sound right to me — to raise the sea level 3 feet. I mean, yeah, we have some glaciers and ice caps that are melting, but they’d have to melt a hell of a lot to do that.”

Franke said the community should remain positive, and other officials share his optimism.

“Most of the information that I’ve heard is it could be one to three feet, and I’m hearing it could be more like one to one and a half feet over the next 100 years,” SPI City Manager Dewey Cashwell said.

While making clear he defers all debate of possible sea level increases to scientific experts, Cashwell later pointed to improvements in technology that reduce emissions of greenhouse gases and the potential for accelerated technological advancements. He trusts in technology to provide solutions to help South Padre Island, he added.

“We are certainly conscious of (global warming) today, not only because of the rising sea level but because of the other compromises in our environment from flora and fauna to air quality. These things are being affected by how we live.”

The dire predictions appear to depend on society doing nothing in response, Cashwell said.

More information needed

Although predictions of a 3-foot increase are plausible, it is of the more “extreme” of the scientific community’s “conservative estimates” for what could happen without the dynamic acceleration of melting at the earth’s polar ice caps, said Charles Jackson, a research scientist at the Institute of Geophysics at the University of Texas in Austin.

“Glaciologists are keen on understanding what changes may occur, but they’re starting from zero,” Jackson said.

Scientists have made longstanding pronouncements that the world’s oceans will start rising at an accelerated rate because of global warming. Approximately 100 years ago, sea level was a little more than 7 inches lower than today. Over the next 100 years, seas could rise approximately a foot and a half to 3 feet, some scientists say.

A United Nations report in 2001 predicted at least a 1½-foot-ocean rise within 100 years.

“This is not truth with a capital T,” Richard Alley, an Evan Pugh professor of geosciences at Penn State University, told the Island Breeze in September 2005. “The sea level has been coming up, and it will continue to come up and it’s likely to accelerate.”

The problem for the Island isn’t just global warming or rising sea levels, geoscientists that included Alley said. The challenge facing the Island is to prevent the barrier island from doing what it naturally does: shift and erode with ocean changes.

In May 2006, Environmental Defense, a nonprofit watch group, issued a publication, “Fair Warning: Global Warming and the Lone Star State.” The report warned that increasing sea levels this century could have devastating effects, especially for South Padre Island.

“If the sea level rises by three feet, South Padre Island will be lost,” the report stated. “Much of Galveston Island would be uninhabitable.”

In 2004, based on projections that sea levels could rise more than a foot and a half this century, a U.S. Geological Survey study identified highly vulnerable areas of the Padre Island National Seashore, which starts north of the Port Mansfield jetties and extends nearly 70 miles to the north through Willacy, Kenedy and Kleberg Counties into Nueces County by Corpus Christi.

Approximately 20 miles of beach in Kenedy County near the Kleberg County line faces a low vulnerability to sea level changes, while the rest of the refuge ranges from moderate to very high, according to the report.

Areas were most vulnerable where dunes were not stable and tides could wash over and erode the structures, according to the report, which was based on the same U.S. Geological Survey as the University of Arizona maps.

Research is needed to determine the appropriate response to protect the park system’s beaches on South Padre Island, the report stated.

“However, an accurate and quantitative approach to predicting coastal change is difficult to establish,” the report stated. “Even the kinds of data necessary to make shoreline response predictions are the subject of scientific debate.”

Computer models limited

Jackson agreed that computer models may not make accurate predictions at the regional level, such as determining how rising seas will impact South Padre Island and specific river basins like the Rio Grande.

“With climate models, you don’t tend to trust its regional predictions much,” Jackson said. “When you get to a river basin level, you have to take a climate model’s predictions with a grain of salt.”

The models’ weaknesses at a regional level come from not knowing all the possible environmental influences, Jackson said.

Cashwell does not deny the Island will be impacted by a rise in sea levels.

“I know that there will be some impact on the Island. If the oceans rise, we will certainly see higher sea levels and potentially diminished beaches,” Cashwell said. “On the other hand, the issues that have been prevalent and cause erosion of our beaches now may diminish in the future.”

For example, global warming could cause more frequent rains that could enliven the Rio Grande and then pump more sediment into the Gulf of Mexico that could benefit the coast by providing more depository material for Boca Chica beach and South Padre Island, Cashwell said.

Jackson agreed partly with that prospect.

“We expect rainfall to be more intense in the future. It’s hard to think through all the implications and we still have to do more of that,” Jackson said. “It’s hard to give one answer, because you may be looking at one aspect. Increased rainfall could help. Nobody that I’m aware of has done that computation. What does that translate for increase sediment and erosion? I’m sure there’s a connection there.”

Also absent from computer models are unanswered questions of what communities might do to preserve or elevate coastal areas.

“What that (predictions of sea level rise and computer models) means is if you did nothing and had a 3-foot sea level rise, then of course those places will be underwater,” Jackson said. “People will do things, so it doesn’t mean those places would be lost if people would intervene.”

The human factor

Humans do what is necessary to stay where they want to be, Cashwell said.

“I will point to what took place in Galveston with the situation following a hurricane around the turn of the century,” Cashwell said. “It was cataclysmic … and they essentially went in and lifted the city up several feet.”

If the costs of preserving South Padre Island are considered worthy by people, Cashwell said, then people will adapt to the environment here.

“The beach renourishment efforts are just one phase of that,” Cashwell said. “I would expect that if this property is continued to be valued for the purposes it now serves, folks will find millions over the next 100 or 50 years to address the concerns that are greatest to them.”

Ingenuity, technology, changing building codes and other aspects will also help coastal communities adapt, he said. “That said, it’s all a real crystal ball exercise to state what level the oceans will rise to,” Cashwell said.

People have different reactions to doom-and-gloom scenarios, in part because of films like Al Gore’s “An Inconvenient Truth” that may be scientifically sound in its facts yet still fail to present a “full spectrum of possibility,” Jackson said.

“You want to tell people what answer you’re giving, why you’re giving it and where the uncertainties are,” Jackson said. “Don’t close your ears to the science just because you think people are trying to make political gains about it. There are things to learn about how everything’s connected. Now that we’re learning how climate change can affect the environment, we want to be cautious about it.”

One thing that is not clear is whether the effects of global warming can be reversed. “It takes time to slow down the warming,” Jackson said. “You can’t remove what’s in the atmosphere. It takes time.”

Engineering and planning can overcome coastal property challenges, Cashwell said. “What we have the will to do and the funds to do, we will do,” he said. “But the first thing has to be the will.”

For example, South Padre Island is already planning to embark on the largest beach renourishment project in the history of Texas beaches, he said. “How many folks would have imagined that even 15 years ago?” he asked.

“The bottom line for me is I’m optimistic in humankind’s ability to deal with these issues,” Cashwell said. “I still tell people this on occasion: we are committing an unnatural act out here, and we are doing a heck of a job in committing that unnatural act by living on a sand bar.”

Jackson is also hopeful.

“I’m an optimistic person. I accept the climate may be changing, but I tend to think our society can rally to find solutions,” he said. “Kind of like the suggestion that South Padre Island can add sand to its beaches — that sounds good to me.”