“unprecedented in at least the last 800,000 years,” and that these anthropogenic greenhouse gas (GHG) emissions “are extremely likely to have been the dominant cause of the observed warming since the mid-20th century.”134 The report summarizes the projected impacts of anthropogenic climate change as follows: Temperature Increase: Global average surface temperatures are likely to increase 1.5°C to 2.3°C above the 1850–1900 period by 2050, and temperatures could increase by more than 4°C by 2081–2100 if governments and business do not undertake concerted efforts to mitigate GHG emissions.135 There will be substantial increases in temperature extremes by the end of the twenty-first century, resulting in increasingly frequent unusually hot days and heat waves. 136 Precipitation and Water Resources: Precipitation will increase in intensity in particular regions, resulting in a projected increase in flood hazards in these regions. Climate change is likely to increase the frequency of meteorological, agricultural, and short hydrological droughts.137 There will be significant reductions in surface water and groundwater resources in most dry subtropical regions, thus intensifying competition for water and affecting regional water, energy, and food security.138 This will be driven by, inter alia: (i) reduced rainfall, (ii) reduced snowpack, resulting in less snowmelt supplying rivers and streams; and (iii) increased evapotranspiration and higher temperatures, which in turn further increase the atmospheric demand for moisture from surface water and soils. Sea level rise will also threaten freshwater supply in coastal areas by causing saltwater inundation of surface and ground water. Sea Level Rise: The IPCC projects global mean sea levels to rise by 0.17–0.38 meters by the mid-century (2046-2065) and by 0.26–0.82 meters by the end of the century (2081-2100), as compared with a 1986-2005 baseline.139 Coastal systems and low-lying areas will increasingly experience adverse impacts such as submergence, flooding, erosion, and saltwater intrusion as a result. Increases in precipitation and coastal storms will contribute to these harmful impacts. Impaired Ecosystems: Even under intermediate emissions scenarios, there is a “high risk” that climate change will cause “abrupt and irreversible regional-scale change in the composition, structure, and function of terrestrial and freshwater ecosystems” in this century. 140 Many plant and animal species will be unable to migrate or otherwise adapt quickly enough to changing climactic conditions.141 Climate change will “reduce the populations, vigor, and viability” of many species, especially those with spatially restricted populations, and will increase the extinction risk for many species.142 Climate change-driven “forest dieback,” which has already 134 See INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE, CLIMATE CHANGE 2014: SYNTHESIS REPORT. CONTRIBUTION OF WORKING GROUPS I, II AND III TO THE FIFTH ASSESSMENT REPORT OF THE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (Rajendra K. Pachauri and Leo A. Meyer eds. 2014). 135 IPCC WGII, supra note 75, at 187. 136 Id. 137 Id. at 232. 138 Id. 139 INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE, CLIMATE CHANGE 2013: THE TECHNICAL SCIENCE BASIS, WORKING GROUP I CONTRIBUTION TO THE FIFTH ASSESSMENT REPORT OF THE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE, 90 (Thomas Stocker et al. eds. 2013) [hereinafter IPCC WGI]. 140 IPCC WGII, supra note 75, at 276. 141 Id. at 275. 142 Id. 33