Glaciers in the tropics are threatened

 
By RACHEL MILLAR
Last Updated: Saturday 04 July 2015

global warming is for real, say researchers at Ohio State University, usa. They have presented startling evidence of global warming affecting the tropics at the annual meeting of the American Association for the Advancement of Science. Lonnie Thompson, along with his team, has been carrying out research on glaciers and ice caps around the world for over two decades. Their findings show conclusive melting and retreat of ice in all corners of the globe.

Their research shows that in the Kilimanjaro glacier in Tanzania, about 82 per cent of the ice field has been lost since its first mapping in 1912. "At this rate, all of the ice will be gone by 2020. And this is a conservative estimate," says Thompson. In Peru, the Qori Kalis glacier is retreating at the rate of 60 metres annually. "The loss threatens water resources for hydroelectric power production in the region, crop irrigation and municipal water supplies," Thompson adds. "If this source of power is lost then such countries will need to switch to burning fossil fuels to meet power needs. This will fuel carbon dioxide emissions further."
Himalayas imperilled In India, about 67 per cent of the Himalaya glaciers are retreating. Syed Hasnain, former chairman of the International Commission for Snow and Ice's Working Group on Himalayan Glaciology, says most of the glaciers "will vanish within 40 years due to global warming". It has been observed that the frequency of the occurrence of sudden glacial lake floods increased in the second half of the 20th century, costing lives, property and infrastructure.

These measurements match Thompson's studies of ice cores drilled at four sites on the Tibetan plateau. He compared the ratio of oxygen isotopes, oxygen16 and oxygen18. The greater the oxygen18 enrichment, the hotter the temperatures when ice forms from snow. Using this data, he extrapolated a history of regional temperatures. The Dasuopu glacier, on the southern edge of the Tibetan plateau, showed that the cores in the last 50 years were the warmest in the history of the ice cap. "We have long predicted that the first signs of changes would appear at the few fragile, high-altitude ice caps and glaciers within the tropics...these findings confirm those predictions."

The next Intergovernmental Panel on Climate Change report is expected to comment on these issues. According to Thompson, "This widespread retreat of glaciers may be our clearest evidence of global warming as they integrate many climate variables."

Subscribe to Weekly Newsletter :

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.