Because of human-caused climate change, wASHINGTON — A new study suggests that El Ninos — the natural climatic chaos agent that pops up periodically and spikes global temperatures — are getting stronger.
But observational records only goes back about 75 years, so scientists have previously said the data is too spotty for a trend. Because they are based on ocean temperature differences compared to average, scientists have long theorized that as the world warms, El Ninos would get stronger. Scientists, for example, have looked back at historical records of changes in weather around the world and figured out past El Ninos — such as the super-sized one in 1877 — due to the changes they cause across the globe.
So scientists have looked for clues that indicate an El Nino without measuring water temperatures directly.
The findings come as a strong El Nino that formed a couple months ago is forecast to be the biggest on record in coming months. El Ninos, which are a temporary warming of parts of the equatorial Pacific, warp weather worldwide and increase extreme events, including heat waves, floods in some places and droughts in others. They can cost trillions in damage. Worm quoted the late climate scientist Wallace Broecker who warned “the climate system is an angry beast and we are poking it with sticks. And then Worm added: “Human emissions are the stick and El Nino is of the ‘angry’ outbursts that can be so threatening to our collective safety. “We can either wait many many decades for the instrumental record to get long enough to detect a shift in El Niño properties, or we can use centuries of El Niño reconstructions provided by paleoclimate records. Taken together, the paleoclimate data that we have, from across the Pacific, is fairly consistent in pointing to an intensification of El Niño’s with global warming.
El Ninos are more than 36% stronger than they were before the industrial age began in the mid 1800s, with a 16% jump in just the last 40 years showing that the increase is accelerating, according to a study in Thursday’s journal Science . Because strong El Ninos have much stronger impacts on climate hazards and extremes worldwide, “That’s important. 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,” said study lead author Julia Cole, a paleoclimate scientist at the University of Michigan.
“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,” said Dalhousie University marine scientist Boris Worm, who wasn’t part of the study. “Corals are the gold standard for El Niño reconstruction, and this brings a goldmine of new material to the table,” Cobb said. Both University of Pennsylvania climate scientist Michael Mann — originator of the temperature hockey stick — and University of North Carolina marine scientist John Bruno said that the coral data conflicts with recent observations of water temperature in the Galapagos. Data shows “a substantial decline in recent decades” of El Nino related variations near the Galapagos during the time greenhouse gases increased temperatures the most, Mann said.
