Source : INDIA TODAY NEWS
A new study has found that El Ninos are becoming stronger because of human-caused climate change, with researchers saying the increase closely tracks the rise in global temperatures caused by activities such as burning fossil fuels.
Published in the journal Science on Thursday, the study said El Ninos are now more than 36 per cent stronger than they were before the industrial age began in the mid-1800s. It also found a 16 per cent rise in the past 40 years, suggesting the increase is speeding up. The findings come as a strong El Nino that formed a couple of months ago is forecast to become the biggest on record in the coming months.
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El Ninos are a temporary warming of parts of the equatorial Pacific Ocean that can affect weather patterns across the world and increase extreme events, including heat waves, floods in some places and droughts in others. They can cause trillions of dollars in damage. Study lead author Julia Cole, a palaeoclimate scientist at the University of Michigan, said, “That’s important because strong El Ninos have much stronger impacts on climate hazards and extremes worldwide. When we set out to answer the question of why this might be happening, we set our data up against a record of global temperature, and we found that the increase in El Nino’s strength closely parallels the rise in global temperature that is due to human causes such as the burning of fossil fuels.”
Cole’s study examined El Ninos going back around 900 years. Dalhousie University marine scientist Boris Worm, who was not part of the study, said, “El Nino is the most violent aspect of climate variability worldwide, with effects ranging from local fisheries collapse, to widespread coral die-offs to severe droughts and food shortages around the world.” He also quoted the late climate scientist Wallace Broecker, who had warned that “the climate system is an angry beast and we are poking it with sticks”. Worm added, “Human emissions are the stick and El Nino is one of the angry outbursts that can be so threatening to our collective safety.”
An El Nino’s strength is measured by tracking water temperatures in a part of the central Pacific around the equator and comparing a three-month average with normal levels. If temperatures are 0.5 degrees Celsius warmer than normal, it becomes an El Nino. A reading of 2 degrees Celsius is classified as “very strong”. According to Columbia University’s El Nino tracker, the latest weekly figure stands at 2.7 degrees Celsius and is expected to keep rising for another two to four months.
Scientists have long believed that El Ninos would grow stronger as the world warms because they are based on ocean temperature differences from average conditions. But direct observational records go back only about 75 years, which has made it difficult to establish a long-term trend. To get around that, scientists have looked for indirect signs of El Nino, including historical changes in weather across the world, and used those clues to identify past events such as the super-sized El Nino of 1877. The new study says those longer records show El Ninos have strengthened over time as global temperatures have risen.
With PTI Inputs
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SOURCE :- TIMES OF INDIA
