Predicted 21st century climate variability in southeastern U.S. using downscaled CMIP5 and meta-analysis

Abstract

Trends and variability of the climate in the southeastern United States, including Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, and Tennessee was studied for an array of future scenarios in the 21st century. The region is a biodiversity hotspot affected by more billion-dollar disasters than any other region in the country. Assessing the impacts of climate change in southeastern United States is important and often requires knowledge of plausible future climate change (e.g. scenarios of temperature and precipitation change). Although several methods are available in literature to develop plausible scenarios of the changes, there exists a usability gap [gap between what scientists understand as useful information and what users recognize as usable]. A novel conceptual framework that represents the plausible future climate change scenarios in southeastern United States was developed using information from meta-analysis and outputs from ~19 Coupled Model Intercomparison Project (CMIP5) Global Climate Models (GCMs) [data analysis] in the form of scenario funnels (represent the plausible trajectories of changes in climate). The systematic literature review provided 33 values of precipitation changes from 15 studies and 35 for temperature changes from 14 studies. In general, the meta-analysis revealed, the precipitation changes observed ranged from −30 to +35% and temperature changes between −2 °C to 6 °C by 2099. Fiftieth percentile of the GCMs predicts no precipitation change and an increase of 2.5 °C temperature in the region by 2099. Among the GCMs, 5th and 95th percentile of precipitation changes range between −40% to 110% and temperature changes between −2 °C to 6 °C by 2099. Finally, the usability of scenario information to stakeholders in various southeastern United States ecosystems and guidelines for developing causal chains and feedback loops with three levels of complexity were provided. They include utilizing the information from impact assessment studies, stakeholder's expertise and requirement as well as understanding the potential impacts in ecosystems (e.g. agroecosystems, coastal, wetland) by relating the structural components of an ecosystem, their interactions with each other, within and across ecosystems for improved management and sustainable use of their resources. These would improve understanding of ecosystem functioning for better management and sustainable use of resources. Although the methodology was demonstrated for southeastern United States, it could also be applicable to other regions of the world. However, the scenario funnels, potential impacts on ecosystems and causal chain/loops are subjective to the study region, availability of literature, the changes observed in the literature and data analyzed, the characteristics of the study region, the stakeholder and their requirement.