El Niño is getting stronger

3:05 PM ETDeveloping

World Desk

"It raises the specter of a future where larger El Niño and La Niña events are dialing up the pace and severity of weather and climate extremes.," said Kim Cobb, a coral and climate scientist at Brown University, who wasn't part of the study.

"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.

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.

The temperatures she derived from the fossils over more than 900 years are patchy, with gaps, but when charted it, she said it looks like a hockey stick, the same description used for a 1990s landmark study of past global temperatures.

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.

Cole said measurements of the ratio of calcium and strontium in coral skeletons and of different oxygen isotopes create two independent readings of the seawater in which the coral formed. Cole's team took a novel approach by looking at at what happened to coral over the centuries to act as "a time machine to look into the past," she said.

But observational records only goes back about 75 years, so scientists have previously said the data is too spotty for a trend. "Corals are the gold standard for El Niño reconstruction, and this brings a goldmine of new material to the table," Cobb said.

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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…
"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…
But observational records only goes back about 75 years, so scientists have previously said the data is too spotty for a trend.
Cole's team took a novel approach by looking at at what happened to coral over the centuries to act as "a time machine to look into the past," she said.
Cole said measurements of the ratio of calcium and strontium in coral skeletons and of different oxygen isotopes create two independent readings of the seawater in which the coral formed.
The temperatures she derived from the fossils over more than 900 years are patchy, with gaps, but when charted it, she said it looks like a hockey stick, the same description used for a 1990s landmark study of past…
"It raises the specter of a future where larger El Niño and La Niña events are dialing up the pace and severity of weather and climate extremes.," said Kim Cobb, a coral and climate scientist at Brown University, who…
"Corals are the gold standard for El Niño reconstruction, and this brings a goldmine of new material to the table," Cobb said.

Sources

Gulf News — source text fetched for this pass link