Related by context. Frequent words. (Click for all words.) 58 Holocene 58 mass extinctions 56 volcanism 55 atmospheric CO2 55 Industrial Revolution 55 mass extinction 54 atmospheric carbon dioxide 52 Pleistocene 52 sunspots 51 Ice Age 51 glaciers 50 anthropogenic 50 El Niño 49 plate tectonics 49 latitudes 49 La Nina 49 northern latitudes 49 extinctions 49 El Nino 49 mammoths 49 La Niña 49 Neanderthals 48 epochs 48 glacial ice 47 #.#C [002] 47 diatoms 47 Homo sapiens 47 volcanic eruptions 47 Roman Empire 47 Antarctic Peninsula 47 Middle Ages 47 sunspot 47 glacial 47 PETM 46 Dark Ages 46 tropics 46 millennia 46 Northern Hemisphere 46 warmer temperatures 46 troposphere 46 vernal equinox 46 polar regions 45 upwelling 45 ozone depletion 45 climatologists 45 Cretaceous 45 hominids 45 Greenland ice 45 prehistory 45 heatwaves 45 twentieth century 44 warming 44 coldest winter 44 permafrost 44 Eocene 44 hunter gatherers 44 seventeenth century 44 polar ice 44 ocean currents 43 Triassic 43 Droughts 43 climatic 43 famines 43 coral bleaching 43 boreal 43 Greenland 43 degrees warmer 43 winter solstice 43 Protestant Reformation 43 mild winters 42 cold winters 42 Homo erectus 42 #th century 42 meltwater 42 sixteenth century 42 Neolithic 42 degree Fahrenheit 42 ocean acidification 42 millenniums 42 wetter 42 volcanic activity 42 cold snap 42 Carbon dioxide 42 nineteenth century 41 eighteenth century 41 droughts 41 Mayan calendar 41 Himalayan glaciers 41 peat bogs 41 glacier 41 temperate 41 Bronze Age 41 dinosaurs 41 speciation 41 Antarctica 41 colonization 41 recessions 41 Babylonians 41 warmer 40 Iberian Peninsula 40 Antarctic ice