Related by context. Frequent words. (Click for all words.) 65 stratospheric ozone 58 ozone layer 56 protective ozone layer 54 Ocean acidification 53 hydrological cycle 53 ozone depletion 53 galaxy formation 52 Antarctic ice 52 ocean acidity 52 ozone 52 atmospheric carbon dioxide 52 Ozone Layer 51 species extinctions 50 sunspot cycle 50 Greenland ice 50 greenhouse warming 50 supernova explosion 49 Greenland glaciers 49 gamma ray burst 48 CO2 concentrations 48 mass extinctions 48 volcanic plume 48 greenhouse gas concentrations 48 sunspot activity 48 volcanism 48 World Meteorological Organisation 48 geomagnetic storm 48 glaciation 48 coral bleaching 48 Ordovician 48 infrared telescope 48 Orbiting Carbon Observatory 48 X ray emission 48 marine sediments 47 World Meteorological Organization 47 Greenland Ice 47 atmospheric circulation 47 glacial melt 47 WMO 47 magnetar 47 sunspots 47 icecap 47 solar flares 47 atmospheric CO2 47 mountain glaciers 47 atmospheric concentrations 47 methane hydrates 46 NSIDC 46 polar caps 46 crustal 46 Kilauea Volcano 46 meteoroid 46 particle collisions 46 gravitational waves 46 Antarctica 46 thermosphere 46 Wilkins Ice Shelf 46 gigatonnes 46 aerosol particles 46 cosmic microwave background 45 Tunguska 45 journal Geophysical Research 45 Earth magnetosphere 45 Envisat 45 mass extinction 45 extrasolar planet 45 gas hydrates 45 sunspot 45 algal bloom 45 substorms 45 meltwater 45 volcanic eruptions 45 geomagnetic field 45 El Ninos 45 chlorofluorocarbons 45 upwelling 45 glaciers 44 Serreze 44 extinctions 44 Antarctic Ice 44 supernovae 44 mid latitudes 44 cosmic ray 44 anthropogenic climate 44 polar regions 44 Victoria Crater 44 accretion disk 44 XMM Newton 44 Kilauea volcano 44 methane hydrate 44 astrophysical 44 carbon dioxide CO2 44 supernova explosions 44 planet orbiting 44 troposphere 44 orbiting observatory 44 cosmic rays 44 Global warming 44 Little Ice Age 43 gamma ray bursts 43 geomagnetic storms