Table 3.20 | Summary of previous IPCC assessments of community composition and biodiversity Observations Projections AR5 (Hoegh-Guldberg et al., 2014; Pörtner et al., 2014) The paleoecological record shows that global climate changes comparable in magnitudes to those projected for the 21st century under all scenarios resulted in large-scale biome shifts and changes in community composition, and that for rates projected under RCP6 and 8.5 those changes were associated with species extinctions in some groups