Tree ring scientists Edward Cook (left) and Paul Krusic trekked for nearly two weeks to reach this 1,000-year-old hemlock in the Himalayas of Nepal during their 15-year research. (Brendan Buckley/Columbia University)Friday, April 23, 2010
CBC News
Scientists at Columbia University's the Earth Institute and the Lamont-Doherty Earth Observatory have put together a 700-year record reconstructing the destruction caused by droughts that happened when the Asian monsoon resulted in less than normal rainfall.
The study, Asian Monsoon Failure and Megadrought during the Last Millennium, and the Monsoon Asia Drought Atlas published this week in the journal Science look at the seasonal weather system since 1300, its effects on the continent and how the monsoon's future might impact climate change.
While the monsoon feeds nearly half of the world's population when the rain does fall, when the monsoon fails to provide the usual amount of water and there is a drought, death and destruction are rampant, the study found.
Columbia scientists measured tree data from mature tree rings in 300 locations across the Asian continent, Siberia and northern Australia to come up with the findings.
For most tree species, rainfall determines the width of the species, resulting in annual growth rings, scientists said.
By studying the rings, scientists were able to determine that at least four major droughts led to the devastation in the continent and surrounding areas.
Drought led to fall of China's Ming dynasty
For example, a drought in northeastern China led to the 1644 fall of country's Ming dynasty.
Another drought occurred from 1756-1768, which coincided with the collapse of kingdoms in present-day Burma, Vietnam and Thailand.
The study also looked at the 1876-78 drought known as the "Great Drought," which resulted in widespread famine and the death of a record 30 million people in India, China and present-day Indonesia.
"Global climate models fail to accurately simulate the Asian monsoon, and these limitations have hampered our ability to plan for future, potentially rapid and heretofore unexpected shifts in a warming world," said Edward Cook, the head of Lamont's Tree Ring Lab who ran the study, said in a statement.
"Reliable instrumental data goes back only until 1950. This reconstruction gives climate modellers an enormous dataset that may produce some deep insights into the causes of Asian monsoon variability."
The study follows a similar report in March by the Lamont tree-ring team suggesting that dramatic differences in the monsoon may have influenced the collapse of the ancient Khmer civilization at Angkor — now known as Cambodia — nearly 600 years ago.
That paper, which appeared in the Proceedings of the National Academy of Sciences in the U.S., showed evidence of a mega-drought in the wider region around Angkor from the 1340s to the 1360s, followed by a more severe but shorter drought from the 1400s to the 1420s.
The droughts were combined with severe flooding, resulting in the kingdom's eventual collapse, researchers of that study found.
The research for the latest study was funded by the U.S National Science Foundation.
The study, Asian Monsoon Failure and Megadrought during the Last Millennium, and the Monsoon Asia Drought Atlas published this week in the journal Science look at the seasonal weather system since 1300, its effects on the continent and how the monsoon's future might impact climate change.
While the monsoon feeds nearly half of the world's population when the rain does fall, when the monsoon fails to provide the usual amount of water and there is a drought, death and destruction are rampant, the study found.
Columbia scientists measured tree data from mature tree rings in 300 locations across the Asian continent, Siberia and northern Australia to come up with the findings.
For most tree species, rainfall determines the width of the species, resulting in annual growth rings, scientists said.
By studying the rings, scientists were able to determine that at least four major droughts led to the devastation in the continent and surrounding areas.
Drought led to fall of China's Ming dynasty
For example, a drought in northeastern China led to the 1644 fall of country's Ming dynasty.
Another drought occurred from 1756-1768, which coincided with the collapse of kingdoms in present-day Burma, Vietnam and Thailand.
The study also looked at the 1876-78 drought known as the "Great Drought," which resulted in widespread famine and the death of a record 30 million people in India, China and present-day Indonesia.
"Global climate models fail to accurately simulate the Asian monsoon, and these limitations have hampered our ability to plan for future, potentially rapid and heretofore unexpected shifts in a warming world," said Edward Cook, the head of Lamont's Tree Ring Lab who ran the study, said in a statement.
"Reliable instrumental data goes back only until 1950. This reconstruction gives climate modellers an enormous dataset that may produce some deep insights into the causes of Asian monsoon variability."
The study follows a similar report in March by the Lamont tree-ring team suggesting that dramatic differences in the monsoon may have influenced the collapse of the ancient Khmer civilization at Angkor — now known as Cambodia — nearly 600 years ago.
That paper, which appeared in the Proceedings of the National Academy of Sciences in the U.S., showed evidence of a mega-drought in the wider region around Angkor from the 1340s to the 1360s, followed by a more severe but shorter drought from the 1400s to the 1420s.
The droughts were combined with severe flooding, resulting in the kingdom's eventual collapse, researchers of that study found.
The research for the latest study was funded by the U.S National Science Foundation.
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