Related by context. Frequent words. (Click for all words.) 83 atmospheric carbon dioxide 65 anthropogenic 63 CO2 60 carbon dioxide 59 acidification 58 extinctions 57 carbon sinks 57 carbon dioxide CO2 57 ozone depletion 56 GHGs 55 Little Ice Age 55 greenhouse gasses 55 greenhouse gases 55 phytoplankton 55 water vapor 54 ocean acidification 53 troposphere 53 Greenland ice 52 Carbon dioxide 52 carbon dioxide emissions 52 glaciers 52 greenhouse emissions 52 salinity 52 biosphere 51 global warming 51 greenhouse gas emissions 51 CO2 emissions 51 #ppm [001] 51 Carbon Dioxide 51 GHG emissions 51 photosynthesis 51 permafrost 51 greenhouse gas 50 #.#C [002] 50 mass extinction 50 emissions 50 deforestation 49 oceans 49 warming 49 methane 49 plate tectonics 48 carbon emissions 48 sediments 48 ozone layer 48 atmospheric 48 Antarctic ice 48 melting glaciers 48 heat trapping gases 48 latitudes 48 marine ecosystems 48 peatlands 47 climate change 47 carbon dioxide emission 47 polar regions 47 burning fossil fuels 47 ozone 47 greenhouse gas GHG emissions 47 carbon dioxide CO2 emissions 47 absorb carbon dioxide 46 GHG 46 sulfate 46 emission reductions 46 pollutant 46 polar ice 46 nitrogen 46 biodiversity 46 upwelling 46 aerosols 46 fossil fuels 45 Global warming 45 SO2 45 dissolved oxygen 45 carbon 45 biochar 45 ecosystems 45 volcanic activity 45 carbon emission 44 pH 44 methylation 44 climatic 44 tropical forests 44 mercury emissions 44 soils 44 fossil fuel 44 sunspots 44 Geophysical Research 44 NOx 44 sediment 44 cyanobacteria 44 IPCC 44 climatologists 44 ppm 43 ° C 43 sedimentation 43 Deforestation 43 degree Fahrenheit 43 Himalayan glaciers 43 Emissions 43 depletion 43 precipitation 43 º C