Biodiversity in a changing climate: a synthesis of current and projected trends in the US

© The Ecological Society of America www.frontiersinecology.org W the past decade, the evidence has become unequivocal that global climate is changing and is having widespread effects on biodiversity (IPCC 2007; Bellard et al. 2012). Human understanding of the myriad ways that ecological systems are responding to this unprecedented change is improving, but because biological responses are complex and sometimes unexpected, the full range of possible outcomes remains highly uncertain. In this paper, we assess recent advances regarding the impacts of climate change on biodiversity in the US. By summarizing key messages of a technical input (Staudinger et al. 2012) to the 2014 National Climate Assessment (NCA), which were derived from an extensive literature review, we address (1) current and future effects of climate change on biodiversity, (2) vulnerabilities of and risks to biodiversity, and (3) challenges facing biodiversity conservation. Specifically, we evaluate temporal (eg phenology), spatial (eg range), and organismal (eg physiology) responses of biological systems to climate variables (Table 1), as documented in observational studies, field and laboratory experiments, and various modeling approaches published since the last NCA in 2009 (USGCRP 2009). Within this framework we consider aspects of terrestrial, aquatic, and marine biodiversity, at scales ranging from genes to populations, species, communities, and ecosystems. Finally, to inform natural resource managers and decision makers on biodiversity–climate-change issues, we also discuss critical knowledge gaps, research initiatives, and best management practices. The key findings of the workgroup are shown in italic at the beginning of each of the following sections.