The global warming “hiatus” conversation has returned, while the planet’s temperatures continue to rise they have slowed in the last 15 years. That understanding fueled the arguments of climate change and global warming deniers, was argued about in congressional hearings and split the scientific community to a degree.
Global warming caused a bit of rift in thinking
Last summer the National Oceanic and Atmospheric Administration famously updated their temperature records to essentially show that global warming hadn’t slowed down in the 2000s despite numerous studies that showed that it had.
That argument from last summer could be rehashed with a new piece that was published this week in Nature Climate Change, wherein a number of leading climate scientists challenged NOAA’s conclusion.
“The interpretation [the NOAA group] made was not valid,” said John Fyfe, a climate scientist at Environment and Climate Change Canada and lead author of the commentary. “The slowdown is there, even in this new updated data set.”
The disagreement is a little silly as both groups agree that global warming is real and that 2014 and 2015 broke historic records with high temperatures worldwide. The two camps are simply arguing a slowdown in a decade that has passed.
The argument is spawned by climate models that predicted higher temperatures that never actually occurred. Why the “hiatus” is anyone’s guess, but the consensus suggestion is that cooling aerosols from volcanoes and shifts in the Pacific Ocean that occur naturally could explain it.
Either way, the disagreeing sides have given birth to a group that believes that global warming stopped in 1998, something neither side believes.
We’re fueling climate change deniers and we don’t care
This really is just silly scientific in-fighting designed to see the more vocal critics of the NOAA study receive more grant money to study something that already happened.
Michael Mann, a climatologist at Pennsylvania State University and a co-author of the recently published commentary acknowledges that the fighting may fire up the climate change skeptics but admits that that is not his problem.
“As scientists, we must go where the evidence takes us, we can’t allow our worries about climate contrarians and how they might seek to misrepresent our work to dictate what we do and do not publish,” he said.
The authors of the commentary take exception with the fact that Tom Karl, lead author of the NOAA study and director of NOAA’s National Centers for Environmental Information and his compared the last 15 years to temperatures from 1950 to 1998, obviously a much longer period of time (48 years).
“There is no disagreement that there is decadal variability, and that it is real and needs to be better understood,” said Karl, referring to natural causes of warming.
So what’s the problem guys?
Many scientists believe that the Pacific Decadal Oscillation (PDO) is the reason for the slowdown.
When ocean temperatures rise causing a positive PDO the Earth is hotter than usual. Conversely, when the ocean temps go down as they did in the 2000s global warming is slowed.
“This is the background trend that you would want to compare recent trends against,” says one of the authors (Fyfe).
“These models are not perfect, and they might be overly sensitive,” he said.
Regardless of whether there was a slowdown, global warming is real and 2014 and 2015 show than if there was a slow down there certainly isn’t right now following the record breaking last two years.
“So we have every reason to believe that the warming of the planet and the detrimental impacts of that warming will continue unabated if we do not dramatically reduce our emissions,” Mann said.
