A Framework for Sustained Climate Assessment in the United States
The recent Fourth National Climate Assessment (NCA4) (USGCRP 2017a, 2018a) shows that extensive changes in climate have been observed in all regions of the country. The report states that climate change “creates new risks and exacerbates existing vulnerabilities…presenting growing challenges to human health and safety, quality of life, and the rate of economic growth.” And it concludes that without additional large reductions in emissions, “substantial net damage to the US economy [will occur] throughout this century…” As a result of growing public concern (Leiserowitz et al. 2018), efforts to reduce human contributions to climate change (“mitigation”) and to adjust systems and practices to uncertain future climate conditions (“adaptation”) are gaining traction. These efforts notwithstanding, multiple assessments have concluded that mitigation is not taking place nearly rapidly enough to stabilize atmospheric GHG concentrations at safe levels (e.g., IPCC 2014, 2018). Assessments of the state of adaptation have found that adaptation is progressing, but not fast enough (e.g., Hansen et al. 2012; Bierbaum et al. 2014; Vogel et al. 2016). Finally, practitioners are making long-term plans and investments without consideration of future climate changes and impacts likely to affect the lives and livelihoods of U.S. citizens.