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Friday, May 26, 2017

The Tampa Bay area and climate change: Better pay attention

With the Republican National Convention being held during hurricane season in a city vulnerable to sea level rise, now seems a good time to examine the best scientific evidence concerning how the changing climate will impact the Tampa Bay area. Peer-reviewed science is an objective and dispassionate way for policymakers and the public in the Tampa area to assess the science on sea level rise and climate change — without an alarmist tone. Overzealous so-called "alarmists" are as problematic as ideological skeptics. Many non-experts offer opinions on blogs and television shows. As a rule of thumb, I don't consult my eye doctor when I have chest pains. Recent publications by the Intergovernmental Panel on Climate Change (IPCC), National Academies and American Meteorological Society consider what we know (and don't know) about extreme events and climate change. Most relevant to the Tampa Bay area, heat waves and coastal flooding have been strongly tied to climate change. Solid evidence also exists for impact on drought frequency/severity and heavy rainfall, which can drive floods. The science is less clear on connections to thunderstorms, hurricanes or tornadoes. Climate attribution studies should be used cautiously but certainly should not be dismissed. Here's what we know about how climate changes will affect the Tampa Bay area:
Sea Level: If a doctor gave you a 1 in 6 chance of catching the flu this season, there is a pretty strong likelihood you would get a flu shot. Climatologists at Climate Central recently published a peer-reviewed report and set of interactive maps (http://sealevel.climatecentral.org/surgingseas) showing areas of the Tampa Bay region that have a 1 in 6 chance of flood risk due to sea level rise, storm surge and tide. The study projects a sea level rise for 2020 to 2070 that ranges from 1 to 10 feet. The Tampa Bay Estuary Program notes that water levels in Tampa Bay have been rising roughly an inch per decade since the 1950s. This rate will likely accelerate in coming years. Scientific observations of extraordinary Greenland ice melting this summer have heightened concern. I recently served on a National Academy of Sciences panel commissioned by the Navy to examine climate change and national security. The report (http://www.nap.edu/catalog.php?record_id=12914) highlights how sea level rise challenges military installations. Tampa is home to MacDill Air Force Base, home to CENTCOM. With roughly 95 percent of Florida's population within 35 miles of its coastline, much of Florida's population is vulnerable. Heat: In the past decade, the National Oceanic and Atmospheric Administration and NASA have reported heat record after heat record. In 2011-2012, we observed the warmest 12-month period on record in the United States. Record high temperatures the past several years are outpacing record low temperatures nationwide. In the Tampa Bay region, this could translate to an additional 3 to 7 degrees F added on to summer highs in the next 50 to 100 years. The regions of Florida that experience freezing temperatures will also likely migrate northward. Urban flooding/rainfall: Studies continue to reveal that it "rains harder" now. Urban flooding is increasingly a hazard because stormwater management is designed for 1940s' storms. Infrastructure (i.e., roads, bridges) is also vulnerable to these "new" rainstorms and heat extremes. The 100-year flood, a metric used in a variety of ways (e.g., to set insurance rates), may now be too commonplace, as was suggested in a 2009 University of Georgia-EPA National Weather Service study of the historic Atlanta floods. Hurricanes: The Tampa area has been spared a direct hit by a major hurricane in recent years, but it is not a question of "if" a hurricane will hit but "when." While the literature is still emerging on climate change and hurricanes, a recent study by NOAA scientists suggests that as the climate system warms, major hurricanes — Hurricane Katrina or greater — may be less frequent but more intense. Ocean temperatures are rising as well, and warm water is the fuel for these storms. Stronger storms coupled with elevated sea level clearly means a greater inland storm-surge hazard. "Hidden" impacts: Florida's economy, including that of the Tampa Bay area, depends on agriculture, tourism and fishing. A recent Tufts University study attempted to forecast the impact of climate change to Florida's economy. Researchers found an average loss of roughly $27 billion per year and 300,000 jobs lost by 2025, ($93 billion in losses and 700,000 jobs by 2050) due to loss of tourism revenue, declining property values and increased utility costs. As early as this fall, Floridians could see higher food prices due to the Midwest drought. Wetlands, which are important nurseries for fish and protect against storm surge, will also be vulnerable to the changing climate. The American Meteorological Society, in conjunction with NOAA, recently published the "2011 State of the Climate." Like the IPCC reports, these peer-reviewed studies confirm that natural and human contributions are likely modifying climate. Conjecture on sunspots, lack of warming trends, ice ages and other ideas are mainly distractions and have not been supported by peer-reviewed scientific evidence. Former Gov. Charlie Crist once told legislators that global warming is "one of the most important issues that we will face this century." At a Global Warming and Energy Solutions Conference in 2007, Sen. John McCain, R-Ariz., said, "... unless we reverse what is happening on this planet, my dear friends, we are going to hand our children a planet that is badly damaged." As a father to two young children, that resonates with me. I am honored to serve my country in advisory roles for NOAA, NASA and the National Academies. I fully recognize the value of sage and measured advice. I urge Tampa Bay area residents to consume credible information. That is, defer to evidence — rather than ideology — and pay attention now.

Dr. J. Marshall Shepherd directs the Atmospheric Sciences Program at the University of Georgia and is president-elect of the American Meteorological Society, among other affiliations.
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