Related by context. Frequent words. (Click for all words.) 69 atmospheric CO2 68 atmospheric concentrations 67 atmospheric CO 67 CO2 concentrations 66 atmospheric carbon dioxide 66 atmospheric methane 65 ocean acidity 65 greenhouse gas concentrations 64 species extinctions 61 stratospheric ozone 61 glacial melting 61 greenhouse warming 60 radiative forcing 60 glacial melt 59 hydrological cycle 59 anthropogenic 59 terrestrial ecosystems 59 ozone depletion 59 gigatonnes 58 sunspot activity 58 aerosol particles 57 mid latitudes 57 extinctions 57 Ocean acidification 57 interglacial period 57 anthropogenic climate 56 mass extinctions 56 ozone concentrations 55 gigatons 55 icecaps 55 Younger Dryas 55 El Nino warming 55 glaciers melt 55 global warming 55 #.#C [004] 55 albedo 55 acidification 55 polar caps 55 climate modelers 54 Greenland ice 54 Carbon dioxide emissions 54 Greenland Ice 54 Greenhouse gases 54 nitrous oxides 54 greenhouse gases 54 SO2 emissions 54 mountain glaciers 54 marine sediments 54 GHGs 54 CO ² 54 CO2 54 sunspot cycle 54 Medieval Warm Period 53 greenhouse gasses 53 climate change 53 GHG reductions 53 hotter summers 53 retreating glaciers 53 El Ninos 53 climate alarmists 53 nitrogen fixation 53 ocean acidification 53 Greenland glaciers 53 atmospheric circulation 53 isoprene 52 anthropogenic global warming 52 evapotranspiration 52 melting permafrost 52 decadal 52 preindustrial levels 52 glaciers melting 52 explosive eruptions 52 troposphere 52 nitrous oxide emissions 52 solar nebula 52 manmade global warming 52 biodiversity hotspots 52 volcanism 52 greenhouse gases GHG 51 glaciers 51 #ppm [001] 51 interglacial 51 carbon dioxide 51 lithosphere 51 sunspot numbers 51 salinity 51 equatorial Pacific Ocean 51 polar regions 51 fluxes 51 greenhouse gas emissions 51 thawing permafrost 51 Little Ice Age 51 temperature gradient 51 radioactive decay 51 greenhouse emissions 50 degrees Fahrenheit warmer 50 ocean ridges 50 mass extinction 50 CO -2 50 ozone 50 crop yields