Climate change and its implications for water resources management in south Florida

Recent climate change projections suggest that negative impacts on flood control and water supply functions and on existing and future ecosystem restoration projects in south Florida are possible. An analysis of historical rainfall and temperature data of the Florida peninsula indicates that there were no discernible trends in both the long-term record and during the more recent period (1950–2007). A comparison of General Circulation Model (GCM) results for the 20th century with the historical data shows that many of the GCMs do not capture the statistical characteristics of regional rainfall and temperature regimes in south Florida. Investigation of historical sea level data at Key West finds evidence for an increase in the occurrence and variance of maximum sea level events for the period 1961–2008 in relation to 1913–1960, along with a shift of energy from shorter to longer timescales. In order to understand the vulnerability of the water management system in south Florida in response to changing precipitation and evapotranspiration forcing, a sensitivity analysis using a regional-scale hydrologic and water management model is conducted. Model results suggest that projected climate change has potential to reduce the effectiveness of water supply and flood control operations for all water sectors. These findings emphasize that questions on the potential impacts of climate change need to be investigated with particular attention paid to the uncertainties of such projections.