Related by context. Frequent words. (Click for all words.) 79 atmospheric CO2 75 atmospheric carbon dioxide 59 CO2 58 carbon dioxide 55 extinctions 54 salinity 54 Little Ice Age 54 #ppm [001] 54 ozone depletion 54 greenhouse gasses 53 greenhouse gases 53 carbon dioxide CO2 53 anthropogenic 52 GHGs 52 glaciers 52 Carbon Dioxide 52 latitudes 51 water vapor 50 permafrost 50 #.#C [002] 50 mass extinction 50 biosphere 50 carbon dioxide emissions 49 carbon sinks 49 Greenland ice 49 CO2 emissions 48 atmospheric 48 acidification 48 crop yields 48 greenhouse emissions 48 ozone 48 Carbon dioxide 48 oceans 48 dissolved oxygen 48 methane 48 greenhouse gas emissions 47 global warming 47 phytoplankton 47 heat trapping gases 47 aerosols 47 volcanic activity 46 temperatures 46 photosynthesis 46 sediments 46 ppm 46 emissions 46 carbon emissions 46 ocean acidification 46 absorb carbon dioxide 46 Antarctic ice 46 GHG emissions 46 soils 46 sulfur dioxide emissions 46 temperature 45 pH 45 soil moisture 45 climatologists 45 º C 45 biodiversity 45 Geophysical Research 45 ° C 45 degree Fahrenheit 45 sunspots 45 tropics 45 relative humidity 45 polar regions 45 nitrogen 44 polar ice 44 warming 44 ozone layer 44 carbon dioxide CO2 emissions 44 carbon dioxide emission 44 melting glaciers 44 emission reductions 44 sediment 44 climatic 44 heat trapping greenhouse gases 44 oxygenation 43 plate tectonics 43 biochar 43 Emissions 43 coral reefs 43 climate change 43 tropical forests 43 greenhouse gas GHG emissions 43 deforestation 43 cyanobacteria 43 IPCC 43 SO2 43 climate 43 precipitation 43 sulfur dioxide 43 degrees Fahrenheit 42 snowpack 42 degrees centigrade 42 groundwater 42 seawater 42 soil fertility 42 Deforestation 42 degree Celsius 42 marine ecosystems