Who’s Minding the Planet? HEADLINE 9 SURFACE WATER TURNING THE QUESTION AROUND For years, the modeling experts at the district have reviewed the science and math around climate change and sea level rise. They have reviewed the climate models to determine their applicability in Florida, and have reviewed the papers and technical publications that describe contributions to sea level rise from melting ice in Greenland and Antarctica, oscillations in ocean temperatures, sunspots, and flashier storms. They have collaborated with colleagues in the region to grapple with the uncertainty that plagues modeling projections of sea level and other effects of climate change—especially models that take into account massive numbers of variables—all with uncertainty. Estimates of sea level rise range from half a meter (1.6 feet) to two meters (6.6 feet), which is not nearly specific enough to facilitate planning, Owosina notes. "There is uncertainty in the science. There is uncertainty in the data. And there is uncertainty in the modeling tools themselves," he says. "There's a lot of uncertainty to go around. "We backed away from making predictions," he notes. "Instead of using the models to predict sea level rise, we've turned the problem around to look at the infrastructure we're responsible for and determine what level of sea level will render the infrastructure ineffective. "Then you can set aside the uncertainty and pick a trigger and say, 'when I get to this certain amount of rise, the system starts to operate ineffectively,'" Owosina explains. "If it takes 10 years to build new infrastructure, you set a threshold and say 'just before I hit that level, I'll begin building the new infrastructure.' If the estimates are wrong, you'll just get to the threshold faster, or later." Modeling can help planners in the district or in associated municipalities understand the long-term benefits different adaptation strategies. For instance, Owosina says, a city could enlarge its canals or add pumps to increase floodwater discharge capacity, a fix that could contain flooding and prevent washed-out roads for five or 10 years. But raising the roads—while more expensive—could be a more efficient approach and a longer-term solution to keeping traffic on the move for decades to come. "Things like that are what we can evaluate with models," he says. "We can compare costs and benefits of all cases, and look at what can be most effective in 15 to 20 years, 50 years, or the lifespan of some of the assets that can be 50 to 100 years." "Instead of using the models to predict sea level rise, we've turned the problem around to look at the infrastructure we're responsible for and determine what...will render the infrastructure ineffective." Florida Everglades Akintunde Owosina South Florida Water Management District ENVIRONMENTAL RESEARCH Modeling can also help forecast the role of the district's extensive, $14 billion restoration of the Everglades. Among a wide range of restoration projects, SFWMD is returning water to areas of the Everglades drained decades ago. That should help restore habitat and wetland function. It will also raise surface and ground water on the inland side of the canal system, increasing the region's ability to prevent saltwater intrusion. Every five years, beginning in 2009, SFWMD has also mapped the leading edge of saline water creeping into the aquifer under South Florida, marking its advances and retreats. Movement of the front could indicate a need for new well fields in some areas, Owosina notes. "There is a balance that's struck between the location of the salt and fresh water, and it moves in and out a little bit," he says. "As sea level rises, the tendency is to push that front inland."