C-13/C-12 1,390 C-14 2,595 Calibration 587 Calving 553 Canada--Alberta 548 Canada--British Columbia 599 Canada--Northwest Territories 811 Canada--Quebec 553 Canada--Yukon Territory 725 Carbon 6,084 Carbon cycle 1,226 Carbon dioxide 3,381 Carbon isotopes 3,900 Carnivora 579 Cartography 639 Case studies 971 Cements 622 Cenozoic 18,787 Channels 597 Channels (waterways) 1,177 Chemical analysis 1,365 Chemical composition 4,010 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 793 Classifications 3,201 Clastic rocks 978 Clastic sediments 5,516 Clay 586 Clays 1,149 Clay soils 1,027 Climate 6,572 Climate change 12,254 Climate--Cycles and trends 1,183 Climate effects 2,677 Climate forcing 850 Climatic change 11,922 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 1,207 Coastal topographic features 1,167 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 752 Compressive properties 1,188 Computer applications 4,085 Computerized simulation 1,820 Computer programs 1,239 Concentration 2,337 Concrete admixtures 769 Concrete aggregates 531 Concrete durability 865 Concrete freezing 964 Concretes 754 Concrete strength 1,123 Concrete structures 1,119 Coniferales 495 Conservation 2,385 Construction 2,495 Construction equipment 832 Construction materials 2,029 Continental drift 1,284 Continental margin 771 Continental shelf 1,829 Convection 1,043 Cooling 929 Cores 3,452 Correlation 2,844 Corrosion 502 Cost analysis 1,360 Countermeasures 2,910 Cracking (fracturing) 668 Creep 561 Cretaceous 749 Crust 803 Crustacea 1,127 Crustal studies 791 Cryobiology 815 Cryogenic soils 2,517 Current research 973 Currents 2,455 Cycles 798 Cyclones and anticyclones 513