Related by context. Frequent words. (Click for all words.) 67 glaciation 64 Little Ice Age 59 Medieval Warm Period 57 Pliocene 57 Tibetan Plateau 56 volcanism 56 glacial melt 55 Late Cretaceous 55 Ordovician 55 icecap 55 atmospheric circulation 55 polar caps 54 Holocene 54 El Ninos 54 megafauna 54 crustal 53 mid latitudes 53 Eocene 53 Pleistocene 53 glaciers 52 atmospheric CO2 52 temperate regions 52 mountain glaciers 52 Oligocene 52 Greenland Ice 52 glacial 52 ENSO 51 lake sediments 51 volcanic eruptions 51 sediment cores 51 CO2 concentrations 50 Antarctic Ice 50 glacial ice 50 equatorial Pacific 50 glaciologists 50 radiocarbon 50 ICESat 50 aridity 50 mass extinctions 50 Antarctic ice 50 seismicity 50 Antarctic Peninsula 50 tectonics 50 sunspot activity 50 continental drift 50 greenhouse warming 50 NSIDC 49 geologic 49 diatoms 49 atmospheric concentrations 49 plate tectonics 49 polar regions 49 polar 49 magmatic 49 atmospheric carbon dioxide 49 Cretaceous 49 landforms 48 mass extinction 48 Greenland glaciers 48 decadal 48 Permafrost 48 landmasses 48 subduction 48 isotopic 48 Precambrian 48 meltwater 48 troposphere 48 latitudes 48 Qinghai Tibet Plateau 48 albedo 48 Neandertals 48 Antarctica 48 diatom 48 desiccation 47 permafrost 47 polar ice 47 stalagmite 47 Northern Hemisphere 47 glacier 47 volcanic activity 47 sunspots 47 extinctions 47 mammoths 47 Wilkins Ice Shelf 47 ozone depletion 47 equatorial regions 47 equatorial 47 minima 47 Triassic 47 millennia 46 Serreze 46 gigatonnes 46 epochs 46 Mesozoic 46 melting permafrost 46 basalts 46 prehistory 46 nitrogen fixation 46 Ice Age 46 Arctic Ocean 46 oceanic