Memorandum for the Petitioners | 29 5.13. The Joint Summary of the Amicus Curiae dated 19 March 2018, citing the IPCC AR5 , succinctly summarized the projected impacts of anthropogenic climate change with regard to temperature increase, precipitation and water resources, sea-level rise, impaired ecosystems, effects on buildings, infrastructures, and services, and expanding disease vectors.84 5.14. The 2014 IPCC AR5 states the following key material facts, as summarized by the Joint Summary of the Amicus Curiae: 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. 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. r 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. 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. 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. r Sea Level Rise: The IPCC projects global mean sea levels to rise by 0.17-0.38 meters by the mid-century (20462065) and by 0.26-0.82 meters by the end of the century (2081-2100), as compared with a 1986-2005 baseline. 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. Many plant and animal species will be unable to migrate or otherwise adapt quickly enough to changing climactic - 84 Joint Summary of ( he Amicus Curiae, supra note 50, pp. 33- 34 ( in-text citations omitted).