Related by context. Frequent words. (Click for all words.) 66 atmospheric CO2 65 atmospheric carbon dioxide 65 ozone depletion 64 global warming 64 greenhouse gas concentrations 64 anthropogenic 61 volcanism 59 albedo 59 Little Ice Age 59 mass extinctions 57 warming 57 acidification 57 Greenland ice 56 polar regions 56 ocean acidification 56 mass extinction 56 extinctions 55 climate change 55 Global warming 54 water vapor 52 climatic 52 greenhouse gasses 52 La Nina 51 glaciers 51 permafrost 51 melting glaciers 51 polar ice 51 La Niña 50 El Nino 50 atmospheric 50 greenhouse gases 50 deforestation 50 plate tectonics 50 aerosols 50 climatologists 50 burning fossil fuels 49 Global Warming 49 melting 49 El Niño 49 Antarctic ice 49 chlorofluorocarbons 49 warmer temperatures 49 Trenberth 49 volcanic activity 49 volcanic eruptions 48 coral bleaching 48 carbon sinks 48 Greenhouse gases 48 sunspots 48 carbon dioxide 48 journal Geophysical Research 48 troposphere 48 ozone layer 48 melting ice 48 carbon dioxide methane 48 IPCC 47 upwelling 47 Carbon dioxide 47 climate 47 ocean currents 46 heat trapping gases 46 meltwater 46 magnetosphere 46 gigatons 46 Arctic 46 polar 46 cosmic rays 46 absorb carbon dioxide 46 ultraviolet radiation 46 heat trapping 45 biosphere 45 Geophysical Research 45 Antarctic Peninsula 45 degree Fahrenheit 45 convection 45 PETM 45 methane 45 acid rain 45 perturbations 45 oscillations 45 Antarctic Ice 45 Deforestation 45 speciation 45 vortices 44 Holocene 44 oscillation 44 heatwaves 44 Arctic Ocean 44 Enceladus 44 tropical cyclones 44 boreal 44 carbon dioxide CO2 44 desertification 44 CO2 44 Warming 44 solar flares 44 WMO 44 gas hydrates 43 caloric restriction 43 snowmelt 43 computer simulations