Satellite-derived temperature data suggests the “pause” in global warming is back as the recent El Nino fades and cooler temperatures prevail, according to a new analysis.
Land temperatures have declined to pre-El Nino levels, according to Dr. David Whitehouse, suggesting the El Nino warming event may not have a big impact on the long-term global warming trend.
“The decrease is seen in the land only data,” wrote Whitehouse, the science editor for the Global Warming Policy Forum. “Data from the sea shows a decline but not as much. This is expected given the ocean’s thermal lag.”
“Data from the RSS group that provides satellite temperature services show that late-2016 temperatures have returned to the level it was at post-1998,” he wrote. “This clearly shows the recent El Nino for what it is – a short term weather event. Now that it is over it can easily be seen that the lower Tropospheric temperature displays no long-term trend between 1999 – 2016.”
The recent El Nino that began in late 2015, was incredibly powerful and boosted global average temperature to record levels. El Nino actually broke the so-called “pause” in global warming — a more than two-decade period in the satellite record with no statistically significant warming.
Whitehouse also pointed out it’s uncertain if satellite data will undergo a “step-change” to warmer temperatures, like it’s done in the past. Outside of these “step-changes,” global temperature remains stable in the satellite record, suggesting the warming is largely driven by El Ninos and La Ninas.
“Many have noticed that the strong El Nino of 1998 resulted in a ‘step-change’ in lower atmospheric temperature,” Whitehouse wrote.
“There is no reliable statistical evidence for an increase before it in the satellite data that was available in 1979,” he wrote. “After 1998 the temperature did not return to its previous level but remained at a higher, stable level. It remains to be seen if the temperature will undergo another step-change. It’s very early days but on the sparse data available I think it seems unlikely.”
Scientists and some media outlets sounded the alarm on man-made global warming as El Nino drove February temperatures to their highest level on record.
“We are in a kind of climate emergency now,” Stefan Rahmstorf, a climate scientist at the Potsdam Institute of Climate Impact Research, said in February.
“This is really quite stunning” and “it’s completely unprecedented,” he said.
But satellites temperatures are especially sensitive to El Ninos, and temperatures peaked in February, but began to rapidly decline in the following months — though not fast enough to avoid 2016 likely becoming the warmest year on record.
Experts still predict a somewhat weak La Nina cooling event to persist through the rest of the year and bring “drier and warmer weather in the southern U.S. and wetter, cooler conditions in the Pacific Northwest and across to the northern tier of the nation this winter,” according to the National Oceanic and Atmospheric Administration (NOAA).
Even with the current La Nina, climate scientists still think 2016 could be a record warm year for satellite data. October’s global average temperature report indicated “it would require strong cooling for the next two months to avoid 2016 being a new record-warm year,” according to Dr. Roy Spencer, a University of Alabama-Huntsville scientist who runs a major satellite temperature dataset.