Related by context. Frequent words. (Click for all words.) 65 atmospheric CO 61 gigatons 61 atmospheric CO2 60 gigatonnes 55 CO2 concentrations 54 atmospheric carbon dioxide 54 interglacial period 53 GPa 52 Pliocene 52 interglacial 52 lithosphere 52 #ppm [001] 52 terrestrial ecosystems 52 CO2 52 anthropogenic 52 Supplementary Fig 51 Gt 51 gdp 51 ref. 51 atmospheric concentrations 51 z = 51 CO ² 51 Medieval Warm Period 51 isoprene 50 hydrological cycle 50 Greenhouse Gases 50 earths 50 radiative 50 Co2 49 biosphere 49 megatonnes 49 marine sediments 49 albedo 48 decadal 48 Younger Dryas 48 greenhouse gas concentrations 48 fluxes 48 polar caps 48 preindustrial 48 carbons 48 GeV 48 PETM 48 logarithmic 48 GHGs 48 glaciation 48 isotopic 48 anthropogenic climate 48 greenhouse warming 47 Little Ice Age 47 volcanism 47 glacial melt 47 lavas 47 troposphere 47 continental crust 47 glaciers melt 47 mass extinction 47 ~ 47 Nd 47 SO2 emissions 47 cyclically adjusted 47 Fig. 47 Greenland Ice 47 earth crust 47 mid latitudes 46 sunspot cycle 46 aerosol particles 46 CH4 46 Cf 46 glacial ice 46 N2O 46 dioxide 46 adsorbed 46 ENSO 46 ocean acidity 46 vol 46 ppm 46 microfossils 46 Holocene 46 preindustrial levels 46 megatons 46 NR CC 46 pp #-# 46 kPa 46 biogenic 46 º C 45 olivine 45 SO2 45 Late Cretaceous 45 picosecond 45 carbon dioxide 45 Article PubMed ChemPort 45 Precambrian 45 species extinctions 45 sunspot activity 45 CO2e 45 Article ChemPort 45 methane hydrate 45 abundances 45 Ann Intern Med 45 anion 45 Hg