C-13/C-12 1,395 C-14 2,607 Calibration 588 Calving 553 Canada--Alberta 549 Canada--British Columbia 601 Canada--Northwest Territories 815 Canada--Quebec 553 Canada--Yukon Territory 728 Carbon 6,118 Carbon cycle 1,237 Carbon dioxide 3,395 Carbon isotopes 3,916 Carnivora 579 Cartography 641 Case studies 972 Cements 622 Cenozoic 18,839 Channels 598 Channels (waterways) 1,178 Chemical analysis 1,365 Chemical composition 4,016 Chemical ice prevention 1,025 Chemical properties 1,137 China--Qinghai-Xizang Plateau 524 Chlorophyll 787 Chlorophylls 880 Chordata 4,034 Circulation 1,395 Classification 795 Classifications 3,203 Clastic rocks 978 Clastic sediments 5,533 Clay 588 Clays 1,151 Clay soils 1,027 Climate 6,587 Climate change 12,313 Climate--Cycles and trends 1,183 Climate effects 2,692 Climate forcing 852 Climatic change 11,981 Climatic changes 3,752 Climatic factors 2,262 Climatology 2,895 Cloud cover 776 Cloud droplets 621 Cloud physics 2,349 Clouds 2,488 Cloud seeding 529 Clouds (meteorology) 2,148 Coastal environment 1,215 Coastal topographic features 1,178 Cold tolerance 717 Cold weather construction 3,549 COLD WEATHER CONSTRUCTION 666 Cold weather operation 1,615 Cold weather performance 1,710 Cold weather survival 840 Cold weather tests 758 Communities 754 Compressive properties 1,188 Computer applications 4,091 Computerized simulation 1,820 Computer programs 1,240 Concentration 2,338 Concrete admixtures 769 Concrete aggregates 531 Concrete durability 865 Concrete freezing 964 Concretes 754 Concrete strength 1,123 Concrete structures 1,119 Conservation 2,386 Construction 2,506 Construction equipment 832 Construction materials 2,031 Continental drift 1,284 Continental margin 771 Continental shelf 1,838 Convection 1,044 Cooling 932 Cores 3,457 Correlation 2,844 Corrosion 502 Cost analysis 1,360 Countermeasures 2,915 Cracking (fracturing) 668 Creep 563 Cretaceous 749 Crust 803 Crustacea 1,127 Crustal studies 791 Cryobiology 815 Cryogenic soils 2,517 Cryosphere 527 Current research 975 Currents 2,455 Cycles 801 Cyclones and anticyclones 513