Bristlecone pine and carbon dating
In the summer of 1969, Brunstein convinced a scientist from Harvard University named Val La Marche to come out and investigate the trees.
La Marche took several cores back to the lab, where he noticed an odd pattern.
In 1844, a year tribes and trappers in Colorado called “the time of the big snow,” storms dropped so much snow that when it finally melted, thousands of buffalo lay dead on the prairie. The old trees form so many frost rings, Brunstein said, because they live at about 11,400 feet — the tree line, where the slightest temperature dip can form ice in the cells.
Brunstein has counted 182 frost rings in cores from the region, which, he said, “makes them one of the best indicators of global climate we have.” The record is so complete that archaeologists have used it to help explain an Aztec curse.
So many have used the pine to study the climate that it has become a sort of global black box — a flight recorder for the past 2,000 years of Earth. Still, like all old bristlecones, it seems to exude an enduring nobility. “I loved everything outdoors, and I was really into trees — identifying them, finding their ages.The team used a broad array of natural record keepers to plot the changes — coral reefs, layers of ice, lake sediments and the bristlecones near Pikes Peak.The results showed a relatively flat, stable temperature that suddenly climbed after 1900.Under the microscope, the compact corduroy of rings revealed the normal alternating pattern of light bands of cells made each summer during the growing season and dark bands made at the end of the year as moisture drained from the living tissue in preparation for winter.But the cores also showed dark bands where the cells were smashed and broken like a highway pileup.
The annual rings laid down in the stout trunk, however, are much more widely known.