Barnola et al,Nature, 329, 408-414 (1987) Depth ice Age Gaz age CO2 ppmv mimimum maximum m years years value value 124.6 4050 1700 274.5 279.5 269.5 173.1 5970 3530 270 278 257 250.3 9320 6800 252 262.5 239 266 10040 7500 257 262 252 302.6 11870 9140 259 266 252 375.6 16350 12930 245 250 235 426.4 20330 16250 193 198 183 474.2 24280 20090 194.5 201.5 187.5 525.1 28530 24390 200 205 195 576 32680 28720 198 215 194 602.3 34770 30910 223 232 214 625.6 36600 32800 207 211 203 651.6 38600 34870 210 215 199 700.3 42320 38660 207 211 203 748.3 45970 42310 178.5 196.5 173.5 775.2 48000 44350 200 205 190 800 49850 46220 207.7 214.3 199.3 852.5 53770 50150 201 220 195 874.3 55450 51770 201 213 189 902.2 57660 53860 219.5 229.5 214.5 926.8 59670 55780 214.5 233.5 208.5 951.9 61790 57800 206.5 224.5 201.5 975.7 63880 59770 201 209 193 1002.5 66230 62080 192 195 189 1023.5 68040 63960 193 200 186 1052.4 70470 66540 205.5 225.5 193.5 1074.8 72330 68490 226.5 245.5 215.5 1101.4 74500 70770 243 254 227 1124.19 76330 72690 235 257 226 1148.69 78270 74720 230.5 237.5 223.5 1175 80320 76860 219.5 228.5 210.5 1225.69 84220 80900 222.5 242.5 210.5 1251.5 86220 82820 234 241 222 1274.19 87980 84700 218.8 224.3 213.3 1299.3 89940 86680 210 217 203 1322.5 91760 88520 221.5 238.5 217.5 1349 93860 90630 226 231 216 1374.8 95910 92700 234 238 230 1402.5 98130 94940 226.5 244.5 221.5 1425.5 100000 96810 236 241 231 1451.5 102210 98950 225 231 219 1476.09 104410 101040 229 234 219 1499.59 106610 103130 238.5 249.5 222.5 1526.3 109240 105620 234.5 243.5 225.5 1547 111250 107650 244 256 232 1575.19 113850 110510 233.5 238.5 228.5 1598 115850 112700 240 247 230 1626.5 118220 115290 276 282 270 1651 120170 117410 271.5 278.5 264.5 1676.4 122100 119500 280 290 270 1700.9 123900 121430 271.5 278.5 264.5 1726.8 125730 123380 265.3 270.3 257.3 1774.09 129020 126770 275 282 268 1802.4 131030 128780 266.5 276.5 254.5 1825.69 132700 130460 275 285 265 1850.5 134510 132280 266 285 260 1875.9 136450 134170 296.5 304.5 283.5 1902 138660 136170 266 270 262 1928 141170 138410 246.5 264.5 236.5 1948.69 143440 140430 231 251 224 1975.3 146860 143370 217 221 213 1998 150330 146340 191 209 187 2025.69 154980 150700 200.5 208.5 192.5 2050.3 159100 154970 191.3 198.8 183.8 2077.5 163670 159690 195.5 201.5 189.5