Related by context. Frequent words. (Click for all words.) 57 atmospheric carbon dioxide 57 atmospheric CO2 55 greenhouse gas concentrations 54 #ppm [001] 53 glaciers 52 exabytes 51 greenhouse gases 50 greenhouse gasses 50 Greenland ice 50 degree Celsius 50 carbon dioxide CO2 50 degrees Centigrade 50 CO2 emissions 49 carbon dioxide 49 greenhouse gas emissions 49 mbd 49 Antarctic ice 49 #.#C [002] 49 mb d 49 carbon dioxide emissions 49 CO2 48 Little Ice Age 48 mass extinction 48 emission reductions 48 C# emissions 48 gigawatts 47 degrees centigrade 47 TWh 47 extinctions 47 greenhouse emissions 47 degrees Celsius 47 Greenhouse gases 46 GHGs 46 metric tons 46 ° Celsius 46 anthropogenic 46 carbon emissions 46 cubic meters 46 tonnes 46 greenhouse gas GHG emissions 46 GHG emissions 46 degree Fahrenheit 46 industrialized countries 46 ozone depletion 46 bcm 46 burning fossil fuels 45 climate change 45 º C 45 degrees Fahrenheit 45 heat trapping emissions 45 carbon dioxide CO2 emissions 45 mass extinctions 45 emissions 45 Fossil fuels 45 ppm 44 heat trapping greenhouse gases 44 tropical forests 44 carbon dioxide emission 44 deforestation 44 degrees celsius 44 carbon sinks 44 glacial ice 44 Himalayan glaciers 44 polar ice 44 floods droughts 44 legally binding treaty 43 greenhouse gas 43 IPCC 43 melting glaciers 43 climatologists 43 greenhouse gases emitted 43 Kyoto Protocol expires 43 reducing carbon emissions 43 greenhouse gas emitter 43 mbpd 43 heat trapping gases 42 oceans 42 carbon emission 42 mmt 42 ° C 42 global warming 42 UNFCCC 42 carbon dioxide emitted 42 metric tonnes 42 8 Cyl 42 mln bpd 42 gigalitres 42 permafrost 42 Carbon dioxide 42 WMO 42 Kyoto Protocol 41 emission reduction 41 fossil fuels 41 polar regions 41 mln tonnes 41 carbon dioxide methane 41 peatlands 41 CO2 emission 41 #GW [001] 41 #.#m tonnes [002] 41 tons