Trees can record centuries of history in their rings – changes in rainfall and temperatures, even evidence of fires sweeping through a region or the climatic impacts of volcanic eruptions. Annual rings are common in trees that experience seasonal climate variability and dormancy, but in the tropics, these records are rare. Now, for the first time, scientists have documented consistent annual tree rings in a native species on Hawai’i. The history recorded in the ring widths could improve our understanding of the climate in the eastern tropical Pacific, a region where much of the variability of the El Niño-Southern Oscillation (ENSO) originates.
August 21, 2015
June 11, 2015
A new study of tree rings from Mongolia dating back more than 1,000 years confirms that recent warming in central Asia has no parallel in any known record. In recent decades, temperatures have been ascending more rapidly here than in much of the world, but scientists have lacked much evidence to put the trend into a long-term context. The study does not explicitly raise the issue of human-induced warming, but is sure to be seen as one more piece of evidence that it is at work. The study appears in the journal Quaternary Science Reviews.
May 13, 2013
Eight hundred years ago, relatively small armies of mounted warriors suddenly exploded outward from the cold, arid high-elevation grasslands of Mongolia, and conquered the largest contiguous empire in history. Led by Genghis Khan and his sons and grandsons, the Mongols briefly ruled most of modern-day Russia, China, Korea, southeast Asia, Persia, India, the Middle East and eastern Europe. They reshaped world geography, culture and history in ways that still resound today. How did they do it? Among the forces at work: the Mongols’ fast horses and brilliant cavalry tactics; their openness to new technologies; and the political genius of Genghis himself. Now, a research group is looking into a possible other factor: climate change. The idea may have implications not only for our understanding of history, but for modern Mongolia and the wider world.