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(Click for frequent words.) 61 melting polar 58 melting ice 57 shrinking polar 52 polar ice 52 Watt Cloutier 52 Arctic icecap 51 Melting Arctic 50 Arctic 50 Melting ice 49 melting glaciers 49 Melting glaciers 48 polar icecap 48 glacier melting 47 Greenland ice 47 melting icecaps 47 polar bears 47 Himalayan Glaciers 47 Bob Corell 47 global warming 46 Sheila Watt Cloutier 46 ocean acidification 46 glacial melting 45 melting icebergs 45 Arctic Ocean 45 Antarctic glaciers 45 circumpolar 45 shrinking glaciers 44 Greenland Antarctica 44 glacier retreat 44 glaciers melting 44 acidic oceans 44 Qinghai Tibet plateau 44 methane hydrates 44 glaciers melt 44 Sami reindeer herders 44 polar explorer Roald Amundsen 44 climate change 44 polar bear habitat 44 walrus polar bears 44 Rignot 43 scientist Jay Zwally 43 Amundsen Sea Embayment 43 icesheets 43 melting glacial 43 tropical glaciers 43 permafrost melting 43 receding glaciers 43 Puijila 43 permafrost thaws 43 harp seal population 43 Melting polar 43 Pacific walrus 43 Antarctic ice 43 Greenland 43 glacial melt 42 melting permafrost 42 worsening droughts 42 polar regions 42 Norwegian Polar 42 mountain glaciers 42 Steven Amstrup 42 Jakobshavn 42 melting glaciers disappearing 42 Himalayan glacier 42 Jakobshavn Glacier 42 greenhouse warming 42 permafrost 42 Adélie penguins 42 subglacial lakes 42 floods droughts heatwaves 42 Global warming 42 oceans 42 glacier melts 42 icebergs drifting 42 Kittlitz murrelet 42 polar bear 42 Himalayan river basins 42 glacier shrinkage 41 Norwegian polar explorer 41 melting 41 Arctic seabed 41 oceanic circulation 41 icecap 41 COSEWIC 41 polar icecaps 41 boreal regions 41 glaciers 41 Chukchi Sea 41 Climate Impact Assessment 41 Ursus maritimus 41 Greenland icesheet 41 caribou herds 41 disappearing glaciers 41 Quelccaya 41 Ilulissat glacier 41 Carteret Islands 41 Velicogna 41 Tromsoe Norway 41 Himalaya glaciers 41 Serreze 41 Julienne Stroeve 41 anthropogenic climate 41 glacial retreat 40 Robert Bindschadler 40 polar bears seals 40 Thawing permafrost 40 melt glaciers 40 Greenland glaciers melt 40 coral reef degradation 40 thawing permafrost 40 resource depletion 40 acidifying oceans 40 Highleyman 40 Josefino Comiso 40 Greenland icecap 40 species extinctions 40 polar bears walruses 40 Glaciers melting 40 manmade CO2 emissions 40 Paal Prestrud 40 polar caps 40 Tibetan Plateau 40 Bering Sea 40 climate modellers 40 manmade global warming 40 midlatitudes 40 anthropogenic greenhouse gases 40 migratory seabirds 40 subsistence whaling 40 Waleed Abdalati director 40 fabled Northwest Passage 40 IPY 40 Bjørn Lomborg 40 Amundsen Sea 40 Amstrup 40 Ocean acidification 40 Himalayan glaciers 40 anthropogenic global warming 40 ice melts 39 Waleed Abdalati 39 Quaternary Period 39 glaciology 39 icecaps 39 global warming skeptics 39 polar oceans 39 southern latitudes 39 Antarctic krill 39 Warmer oceans 39 World Meteorological Organization 39 krill 39 glacial ice 39 Northwest Passage linking 39 Arctic Archipelago 39 shadowed craters 39 Lomonosov ridge 39 retreating glaciers 39 Kazlowski 39 Jellyfish swarm northward 39 Alaskan glaciers 39 boreal forests 39 Arctic permafrost 39 Qinghai Tibet Plateau 39 ice calved 39 global warming alarmists 39 Northwest Passage 39 narwhal 39 Greenland glaciers 39 Ammassalik Island 39 Mark Serreze 39 polar 39 mountain snowpacks 39 floods heatwaves droughts 39 heatwaves droughts 39 Eric Rignot 39 Greenland Ice 39 Doug Inkley senior 39 journal Geophysical Research 39 Andrew Derocher 39 Romero Lankao 39 thawing tundra 39 Opposes drilling 39 paleoclimatic 38 Josef Motzfeldt 38 tropic regions 38 Ignatius Rigor 38 glacier melt 38 Global Warming 38 Mojib Latif 38 Jane Ferrigno 38 Ny Alesund 38 droughts floods heatwaves 38 iceberg calving 38 manmade greenhouse gases 38 Muller Karger 38 Lomonosov Ridge 38 Greenland Glaciers 38 Warmer seas 38 British Antarctic Survey 38 Shakhova 38 surface temperatures SSTs 38 eroding coastlines 38 Vatnajökull 38 Rob Huebert 38 Janne Haaland Matlary 38 poleward shift 38 Otto Bliesner 38 icesheet 38 Barents Sea cod 38 polar bears penguins 38 Antarctic Ice 38 droughts heatwaves floods 38 sub glacial lakes 38 meridional overturning circulation 38 Vesterålen 38 Inuit elders 38 Abdalati 38 Seepage detected 38 Kilimanjaro glaciers 38 World Meteorological Organisation 38 Norway Fridtjof Nansen 38 melts glaciers 38 Rossby waves 38 Inuit hunters 38 globalwarming 38 climate modelers 38 Gakkel Ridge 38 Aqqaluk Lynge 38 ocean acidity 38 ringed seals 38 atmospheric CO2 levels 38 ecological degradation 38 drifting ice floe 38 dustier stormier atmosphere 38 Shishmaref 38 moon Europa 37 cryosphere 37 Holocene epoch 37 polynyas 37 albedo feedback 37 Polar Regions 37 polar bear populations 37 Greenland glacier 37 Himalayan glaciers melting 37 geophysicist Scott Luthcke 37 arctic permafrost 37 paleoclimatology 37 melts Himalayan glaciers 37 Korty stressed 37 glaciologists 37 floods droughts desertification 37 Nature Geoscience journal 37 cyanobacterial blooms 37 icebergs 37 NSIDC 37 Year IPY 37 Jacob Verhoef 37 Antarctica 37 Ilulissat Greenland 37 narwhals 37 planetary warming 37 Inupiat natives 37 glaciers retreating 37 Bering Seas 37 mountain pygmy possum 37 Cook Inlet beluga whale 37 Syun Ichi Akasofu 37 Mediterranean bluefin tuna 37 Al Gore Inconvenient Truth 37 deep convective clouds 37 Polar bear 37 overfishing 37 barren tundra 37 Martian polar 37 Circumpolar 37 ozone depletion 37 Jakobshavn Isbrae 37 melting glacier 37 antarctic 37 seabeds 37 glacial meltwater 37 atmospheric methane 37 Xuebin Zhang research 37 Aiguo Dai 37 Kangerdlugssuaq 37 arctic 37 Biogeography 37 dissolving coral reefs 37 Dronning Maud Land 37 superstorms 37 melt Himalayan glaciers 37 heatwaves droughts floods 37 Dennis Bueckert 37 sequestering carbon dioxide 37 seabed 37 permafrost degradation 37 Pastoruri 37 Achim Steiner UNEP 37 Walruses dive 37 Alberta oilsands 37 Ozone depletion 37 Tharsis Rise 37 springtime ozone 37 Beaufort Sea 37 ocean basins 37 WMO 36 icefields 36 Arctic Circle 36 geological epoch 36 southernmost continent 36 EFIRE 36 inundate coastal 36 driest continents 36 Antarctic Ice Shelf 36 climate alarmism 36 glacial shrinkage 36 caribou 36 greater sage grouse 36 Arctic archipelago 36 amphibian declines 36 gas hydrates 36 Skeptical Environmentalist 36 shaded craters 36 Peary caribou 36 warming 36 heatwaves floods droughts 36 warmings 36 authoritative Intergovernmental Panel 36 hotter summers 36 Sheldon Drobot 36 Artic Ocean 36 hypoxic zone 36 Svalbard archipelago 36 southerly latitudes 36 admiral asks 36 Polar bears 36 glaciers recede 36 North Pacific Gyre 36 dunes sagebrush lizard 36 lumbering polar bear 36 Ontario Lacus 36 deglaciation 36 Shasta glaciers 36 Climate Change IPCC 36 Jupiter moons Europa 36 Bindschadler 36 Climate Change Rajendra Pachauri 36 chairman Rajendra Pachauri 36 Peter Ewins 36 meltwater 36 permafrost melts 36 Janos Bogardi 36 equatorial Pacific oceans 36 Nature Geoscience 36 Akademik Ioffe 36 Inuits 36 Sea otters 36 Korty reiterated 36 circumpolar Arctic 36 groundwater depletion 36 Overfishing pollution 36 seabird colonies 36 depleting fossil 36 catastrophic floods droughts 36 upwellings 36 Konrad Steffen 36 Greenlanders 36 routinely sloughed off 36 polar bears whales 36 Atlantic meridional overturning 36 acidification 36 Teshekpuk Lake 36 Russ Hopcroft 36 Atlantic thermohaline circulation 36 Gangotri glacier 36 deepwater corals 36 Cook Inlet beluga whales 36 weather beaten sunbleached 36 Geophysical Research 36 Oceanographers 36 Antarctic Peninsula 36 Corinne Le Quere 36 glaciers retreated 36 emperor penguins 36 tundra 36 reindeer herding 36 La Nina occurs 36 Spitsbergen archipelago 36 Joan Kleypas 36 Glaciers 36 topsoil erosion 36 Paleoclimate 36 Bluefin tuna 36 Glaciologists 36 stratospheric ozone depletion 36 polar bears walrus 36 Alaskan tundra 36 Disko Island 36 cave stalagmites 36 Lake Yoa 36 Climate alarmists 36 Nuuk Greenland 36 Georg Kaser 36 vexes travelers 36 hydrological cycle 36 John Drexhage 36 alpine glaciers 35 bowhead whales 35 Harp seals 35 Barents 35 subarctic regions 35 global warming alarmism 35 journal Climatic Change 35 IUCN Red 35 thicker streaks 35 Hamish Pritchard 35 Pacific leatherback sea 35 polar voyages 35 ribbon seals 35 Robert Corell 35 Artic 35 El Nino periodic 35 NASA satellites orbiting 35 critically endangered endangered 35 Inuit 35 Methane hydrates 35 Protectionist pressures 35 antarctic ice 35 Yangtze finless porpoise 35 Shrinking glaciers 35 Vaclav Smil 35 glacier calving 35 Polar Biology 35 Gabriel Vecchi 35 Antarctic peninsula 35 Canada Boreal Forest 35 anthropogenic aerosols 35 Jay Lawrimore chief 35 Ilulissat 35 glaucous gulls 35 Acidification 35 spectacled eider 35 methane clathrates 35 polar bear cubs 35 equatorial waters 35 El Nino warming 35 Alberta tarsands 35 halogenated gases 35 Walt Meier 35 Yangtze basin 35 megafauna extinction 35 spoon billed sandpiper 35 amplification Zwally 35 Arctic Svalbard 35 sheet Summerhayes 35 Waters Pollution Prevention 35 Nils Stenseth 35 receding glacier 35 Eric Steig 35 prey ringed seals 35 An Inconvenient Truth 35 bowhead whale 35 towering icebergs 35 Hardanger Fjord 35 Trudy Wohlleben 35 Nenana Basin 35 Sea ICES 35 Antarctic Treaty Consultative 35 northwestern Hawaiian Islands 35 woodland caribou 35 ocean ecosystems 35 Samuel Thernstrom 35 Eyjafjallajökull glacier 35 subpolar 35 Franklyn Griffiths 35 Ocean Acidification 35 boreal 35 An Irritating Truth 35 Sheet WAIS 35 methane hydrate deposits 35 Igor Semiletov 35 gray whales 35 palaeoclimate 35 penguin species 35 bioavailable iron 35 snowier winter 35 Climatic Change 35 seals walrus 35 methane clathrate 35 deforestation desertification 35 Isle Royale wolves 35 Veerabhadran Ramanathan 35 Maui dolphin 35 geodynamics 35 Subarctic 35 icebergs calving 35 Laptev Sea 35 warmer winters 35 cod fisheries 35 Polar Bear Specialist 35 Antartic 35 journal Meteoritics 35 marine mammals 35 continental shelf 35 Chukchi Cap 35 polar bears caribou 35 Andreas Schild 35 Roger Pielke Jr. 35 Antarctic minke whales 35 gobal warming 35 Scheraga 35 authors Kevin Trenberth 35 penguin colonies 35 amphibian extinction 35 clathrates 35 Alpine glaciers 35 GLOBAL warming 35 snowcap 35 Tom Nalepa 35 Scotian Shelf 35 geoengineering schemes 35 underwater Lomonosov Ridge 34 Serengeti ecosystem 34 Antarctic 34 benthos 34 methane seeps 34 Aatami 34 Living Oceans 34 Steller sea lions 34 Tropical deforestation 34 climate alarmists 34 glacial geology 34 cod fishery 34 Dorthe Dahl Jensen 34 marine ecosystems 34 Laurentide ice sheet 34 Bjorn Lomborg Danish 34 Cynthia Rosenzweig 34 ecoregions 34 Syed Iqbal Hasnain 34 porbeagle 34 overexploit 34 Seward Peninsula 34 outlet glaciers 34 anomalously warm 34 permanently shadowed craters 34 ivory gull 34 Premier Hans Enoksen 34 Bohai Sea 34 Brenda Ekwurzel climate 34 Atlantic cod fishery 34 shrinking 34 ecological overshoot 34 Pedro Martinez Arbizu 34 biodiverse ecosystems 34 Tropical rainforests 34 cetaceans whales dolphins 34 Sermilik Fjord 34 subsurface ocean 34 Greenhouse gases 34 climatic anomalies 34 Hik 34 overhunted 34 Lik zinc lead 34 Plate tectonics 34 Ny Ålesund 34 oxygen depletion 34 mammal extinctions 34 ICESCAPE 34 Derocher 34 continental drift 34 Narsaq 34 Antarctic Circumpolar Current 34 Tromsoe 34 rampant deforestation 34 Okhotsk Sea 34 seafloor habitats 34 desertification 34 moon Enceladus 34 subduction faults crisscrossing 34 Domain Awareness 34 Cryogenian 34 Frumhoff 34 AGW hypothesis 34 Professor Hoegh Guldberg 34 Raincoast Conservation Society 34 Avoiding Dangerous Climate Change 34 Volcanic eruption 34 perma frost 34 AP Interview CG 34 Inuit Circumpolar Conference 34 Millennium Ecosystem Assessment 34 spawning kokanee 34 Whillans Ice Stream 34 harp seal pups 34 CoML 34 pikas 34 Kola Peninsula 34 Jonathan Overpeck 34 El Nino La Nina 34 Icelandic whalers 34 Canada COSEWIC 34 Puget Sound killer whales 34 Melting Glaciers 34 Gerald Meehl 34 Tad Pfeffer 34 Stefan Rahmstorf 34 Polar Vortex 34 Nate Mantua 34 extinctions 34 meltwater stonefly 34 Hotter summers 34 Wyoming pocket gopher 34 gigatonnes 34 reef habitats 34 Polar explorers 34 paleoclimate 34 seepage detected 34 scalloped hammerhead shark 34 planets atmospheres 34 subarctic 34 polar craters 34 Rebecca Aldworth 34 Martian arctic 34 Melting permafrost 34 Arctic Caribou Herd 34 Arctic foxes 34 bark beetle infestations 34 ArcticNet 34 enforcing clawbacks poisons 34 Lake Vostok 34 Bering Glacier 34 fin whales 34 volcanic activity 34 Ocean acidification refers 34 Danish fjord 34 aerosol concentrations 34 interglacial period 34 Caspar Ammann 34 IGBP 34 Noctilucent clouds 34 marine ecosystem 34 atmospheric carbon dioxide 34 Sermeq Kujalleq 34 shadowy craters 34 Chukchi Seas 34 Grise Fiord 34 Barents Seas 34 ice floes 34 NASA Zwally 34 Richard Lindzen 34 Bellingshausen Sea 34 Intergovernment Panel 34 Catlin Arctic 34 sea turtle populations 34 Edith checkerspot butterfly 34 Frobisher Inn 34 Arctic ice floes 34 moon permanently shadowed 34 Toolik Field Station 34 Norwegian Barents Secretariat 34 Chuckchi 34 anthropogenic greenhouse gas 34 sea otters 34 Irrawaddy dolphin 34 Martin Sommerkorn 34 subtropical regions 34 Wilfried Haeberli 34 AGW theory 34 Von Frese 34 Alsek 34 Christopher Flavin 34 Natalia Shakhova 34 Melting Ice 34 oceanic ecosystems 34 Sergey Zimov 34 ozone layer depletion 34 ice bergs 34 seabirds 34 Marilyn Heiman 34 Antarctica EPICA 34 Cook Inlet belugas 34 climategate controversy 34 Eaarth 33 storied snows 33 Bjoern Lomborg 33 flood basalts 33 GISS analysis 33 Kristin Laidre 33 Adelie penguins 33 tropical coral reefs 33 polar expeditions 33 climate deniers 33 damaging ultraviolet radiation 33 driest continent 33 Svalbard Islands 33 deforestation overfishing 33 Service WGMS 33 boreal forest 33 Doomsday Seed Vault 33 Weather Makers 33 Snowball Earth 33 stratospheric ozone 33 refrozen ice 33 Nirlungayuk 33 overhunting 33 freshwater streams 33 Warming 33 geologically unstable volcanic 33 TrES 4 33 cryovolcanism 33 fragile marine ecosystems 33 minke whales 33 Simone Tilmes 33 Mary Giovagnoli director 33 Luthcke 33 GRID Arendal 33 Inuit goddess 33 elephant poaching 33 Antarctic glacier 33 nonnative snakes 33 Shad O'Neel 33 Ted Scambos 33 permafrost soils 33 spiny dogfish 33 Overpeck 33 Bicknell thrush 33 spawning herring 33 tectonic plate movements 33 waterbird species 33 climatic variability 33 Danish statistician 33 Bjorn Lomborg author 33 anthropogenic warming 33 Petermann Glacier 33 ° C warmer 33 droughts heatwaves 33 Siple Dome 33 severe droughts 33 marbled murrelet 33 sulphate aerosols 33 coral ecosystems 33 isostatic rebound 33 floods droughts heat 33 subsistence hunting 33 calving glaciers 33 whales walruses 33 alone Reheis Boyd 33 coccolithophores 33 Latady Island 33 Saturn moon Enceladus 33 Pachauri IPCC 33 Lohachara 33 Mark Serreze senior 33 Marika Holland 33 temperature reconstructions 33 Keya Chatterjee 33 Minke whales 33 Inconvenient Truth 33 mass beachings 33 encroaching deserts 33 equatorial Pacific Ocean 33 magnetic substorms 33 toxic algal blooms 33 Zeebe 33 glaciologist 33 Last Glacial Maximum 33 sea 33 caribou herd 33 Natalie Mahowald 33 northern spotted owls 33 biogeochemical processes 33 becoming scarcer 33 Porcupine caribou 33 scientist Ron O'Dor 33 marbled murrelets 33 Ozone Hole 33 warmer wetter winters 33 sea otter 33 Sugata Hazra 33 GLOBAL WARMING 33 winter snowfalls Luthcke 33 Climate Change IPPC 33 Dr Benny Peiser 33 biggest Adelie penguin 33 Jared Gobel 33 North Pole 33 eroding shorelines 33 bearded seals 33 teleconnections 33 boreal caribou 33 Bycatch 33 Extinctions 33 large oceanic plateaus 33 deforestation 33 Jovian moon 33 floods heatwaves 33 Polar bears depend 33 Makivik Corp. 33 Nasa Goddard Institute 33 chinstrap penguins 33 Sei whales 33 Trenberth 33 subsistence hunters 33 Climate Impacts Group 33 climate 33 freshwater ecosystems 33 hotter drier summers 33 Svalbard Archipelago 33 rising 33 Stockholm Resilience 33 nitrogen deposition 33 melting Himalayan glaciers 33 Clare Demerse 33 Czech Hydrometeorological Institute 33 central equatorial Pacific 33 Teshekpuk 33 oceanographers 33 Iliamna Lake 33 undersea plumes 33 Ice Ages 33 Fram Strait 33 freshwater dolphin 33 Galapagos volcano erupts 33 Westfjords 33 Corot 7b 33 pollinator populations 33 black browed albatross 33 Ecoscience Population Resources 33 Cassin auklet 33 Norway Svalbard 33 boreal ecosystems 33 International Geosphere Biosphere 33 global warming skeptic 33 Stephanie Pfirman 33 Ekwurzel 33 eruptive activity 33 yellow billed loon 33 Eduardo Zorita 33 Carl Gustaf Lundin 33 Great Bear Rainforest 33 Steven Guilbeault 33 sealskin 33 UN Intergovernmental Panel 33 Nunavut Territory coal 33 Beaufort Seas 33 CryoSat mission 33 Scambos 33 Chukchi 33 Galilean satellites 33 La Niña pattern 33 Luterbacher 33 Permafrost 33 northern latitudes 33 basalt lava 33 Bering Sea pollock 33 Climate Impacts 33 Nature IUCN Red 33 bonneted bat 33 Chukchi seas 33 Achim Steiner Executive 33 northern rockhopper penguins 33 decadal variability 33 Alan Durning 33 sandeels 33 snowcaps 33 Climategate scandal 33 Brigham Grette 33 jellyfish swarms 33 habitable worlds 33 frozen wasteland 33 Beluga whales 33 Chief Executive Jasmine Whitbread 33 permanently shadowed regions 33 retreating glacier 33 Martian gullies 33 waterfowl habitats 33 Thorthormi 33 Yangtze River dolphin 33 Cosmic Microwave Background 33 increased storminess 33 Stratospheric ozone 33 comb jellyfish 32 Cook Inlet basin 32 birds amphibians reptiles 32 Polar bear cub 32 Environment Programme Unep 32 Fred Grassle 32 Yellowstone caldera 32 Sperm whale 32 dogsled expedition 32 Whitney Lackenbauer 32 Inuit peoples 32 Appy Sluijs 32 Garbage Patch 32 kept mountainous snowbanks 32 Stellwagen Bank 32 NCAR scientist 32 Ice Sheet 32 Oceans 32 Nunavut Tunngavik 32 Steve Amstrup 32 GJ#b 32 oily bilge water 32 glacier 32 journal Geology 32 coral reef bleaching 32 thinning ozone layer 32 Cumbre Vieja 32 penguin rookery 32 harp seals 32 moulins 32 Michel Jarraud 32 climate modeler 32 phytoplankton blooms 32 Patagonian glaciers 32 Norwegian explorer Fridtjof 32 hurricanes Landsea 32 Barents Region 32 endangered whales 32 coastal inundation 32 reindeer herds 32 Arctic Barents Sea 32 Barents Kara 32 cyclonic storms 32 Straneo 32 anthropogenic CO2 emissions 32 vast Myrdalsjokull ice 32 Jiaolong 32 Meeting ATCM 32 Jamie Pittock 32 oilsands 32 Creamsicle orange 32 Antarctic penguins 32 combatting global warming 32 chloride concentrations 32 planet habitability 32 Glacial melting 32 degrees Fahrenheit warmer 32 yedoma 32 Gangetic dolphins 32 thermal vents 32 golden toad 32 radar altimetry 32 iron fertilization 32 groundfish stocks 32 Pen Hadow 32 magma thrashed 32 Roger Revelle 32 GHG concentrations 32 alarmism 32 seal hunt 32 Barents Euro 32 skuas 32 Vastitas Borealis 32 thermohaline circulation 32 climatologists 32 Spitzbergen 32 polar vortex 32 missing baryons 32 Chainsaw massacre 32 Amazonian forests 32 MONTROSE Holistic Health 32 plankton blooms 32 Mud volcanoes 32 Pechora Sea 32 Indian climatologist Rajendra 32 seas droughts floods 32 Lake Turkana 32 carbon dioxide concentrations 32 biodiversity 32 Unep 32 mantle plumes 32 subtropical oceans 32 Kerguelen Plateau 32 Boreal forests 32 wolverine habitat 32 Deadhorse Alaska 32 glacial earthquakes 32 active volcanism 32 Antarctica Amundsen 32 Jay Zwally 32 threatened woodland caribou 32 bowheads 32 Equatorial Pacific 32 Bewick swan 32 Lake Untersee 32 biospheric 32 Keeling Curve 32 Weddell Sea 32 Changing Climate 32 Corinne Le Quéré 32 virgin rainforests 32 Le Quere 32 environmental degradation 32 Woodland caribou 32 clogging waterways 32 chlorophyll concentrations 32 Antarctic ozone 32 Boot Knut