An enormous U.N. report on the scientific data behind global warming was made available Monday, yet it offers little concrete explanation for an earthly oddity: the planet’s climate has hit the pause button.
Since 1997, there has been no significant increase in global average surface temperature, and some areas — notably the Northern Hemisphere — have actually cooled. The 2,200-page new Technical Report attributes that to a combination of several factors, including natural variability, reduced heating from the sun and the ocean acting like a “heat sink” to suck up extra warmth in the atmosphere.
One problem with that conclusion, according to some climate scientists, is that the U.N.’s Intergovernmental Panel on Climate Change (IPCC) has limited the hiatus to 10-15 years. Anastasios Tsonis, distinguished professor at the University of Wisconsin – Milwaukee, believes the pause will last much longer than that. He points to repeated periods of warming and cooling in the 20th century.
“Each one of those regimes lasts about 30 years … I would assume something like another 15 years of leveling off or cooling,” he told Fox News.
That goes well beyond the window the IPCC has acknowledged, which Tsonis and other scientists believe will significantly change the predictions for temperature rise over the next century.
“I know that the models are not adequate,” Tsonis told Fox News. “There are a lot of climate models out there. They don’t agree with each other – and they don’t agree with reality.”
In fact, the IPCC’s massive, complex new report acknowledges that none of the models predicted the hiatus. The authors write that it could be due to climate models over-predicting the response to increasing greenhouse gases, or a failure to account for water vapor in the upper atmosphere.
The bottom line – no one saw it coming.
“Almost all historical simulations do not reproduce the observed recent warming hiatus,” the report states.