Canadian Arctic Temperatures At Their Highest In 44,000 Years
“The key piece here is just how unprecedented the warming of Arctic Canada is,” Professor Gifford Miller said. A fellow at CU-Boulder’s Institute of Arctic and Alpine Research who led the study, Miller says that “this study really says the warming we are seeing is outside any kind of known natural variability, and it has to be due to increased greenhouse gases in the atmosphere.” With his colleagues, Miller used dead moss clumps emerging from melting ice caps from the island as tiny calendars. Boasting of four different ice caps, radiocarbon dates show the Along mosses had not been exposed to the elements since at least 44,000 to 51,000 years ago. Radiocarbon dating is only accurate to about 50,000 years. Since Earth’s geological record shows it was in a glaciation stage prior to that time, the indications are that Canadian Arctic temperatures today have not been matched or exceeded for roughly 120,000 years. Compiling the age distribution of 145 radiocarbon-dated plants in the highlands of Baffin Island that were exposed by ice recession during the year they were collected proved daunting to researchers. All samples collected were within one meter of the ice caps, which are generally receding by two to three meters a year. Reconstructing the past climate of Baffin Island beyond the limit of radiocarbon dating, the team used data from ice cores previously retrieved by international teams from the nearby Greenland Ice Sheet. Summer temperatures cooled in the Canadian Arctic by about five degrees Fahrenheit from roughly 5,000 years ago to about 100 years ago.
