According to Penn State University researchers, the recent global warming slowdown represents a “false pause.” Observing what they describe to be natural oscillations in the climate system, the team went on to conclude that anthropomorphic global warming was not beginning to subside.
“The recent slowdown in global warming has brought into question the reliability of climate model projections of future temperature change and has led to a vigorous debate over whether this slowdown is the result of naturally occurring, internal variability or forcing external to Earth’s climate system,” stated the study authors in their newly published paper.
In a recent press release, the professor of Meteorology at Penn State, Michael Mann, said it was of critical importance to differentiate between man-made climate change and natural shifts in the state of the climate. Mann then went on to explain that the group’s research was necessary to understand the potential impact of human-caused climate change on a number of global phenomena, including drought and extreme weather conditions. “The North Atlantic and North Pacific oceans appear to be drivers of substantial natural, internal climate variability on timescales of decades,” he added.
The team looked at a series of intricate climate simulation models, which had been incorporated into the Intergovernmental Panel on Climate Change’s latest report, alongside real-world observations that dated back to 1854. From this information, the researchers investigated the historical fluctuations in climate variability within the Northern Hemisphere.
The team’s study suggested that both the Pacific and Atlantic Oceans experience natural changes that lead to shifts in the sea surface temperatures; in turn, these natural changes lead to fluctuating cycles of warm and cold periods.
The apparent “false pause” in global warming started around 1998, at a point when the Pacific Ocean “interrupted” the ever-increasing global temperatures. Since this time, the Pacific Ocean has, reportedly, behaved as the Earth’s air conditioner, with deeper layers of the sea trapping much of the heat.
In the coming decades, the researchers predict that the Pacific Ocean will re-enter a warming phase, essentially boosting the impact of global warming. “We are in a turning point right now, and the slowdown will presumably reverse in the decades ahead… When we do, we may see warming even faster than what the models are predicting,” stated Mann.
The study, entitled Atlantic and Pacific multidecadal oscillations and Northern Hemisphere temperatures, was published in the Feb. 27 issue of the journal Science.