Hiatus controversy and beyondAmy Walsh (Author) Published Date : Feb 28, 2016 18:50 IST
The scientific and political controversies surrounding the hiatus have continued to heat up. It was put to rest but resurfaced with a different term altogether.
The United States have been discussing hiatus and the validity of climate models and scientists near-universal consensus that global warming has been man-made.
A global warming hiatus, also sometimes referred to as a global warming pause or a global warming slowdown,is a period of relatively little change in globally averaged surface temperatures.In the current episode of global warming many such periods are evident in the surface temperature record, along with robust evidence of the long term warming trend.
The debate would seem to have been put to rest last year, after scientists from the National Oceanic and Atmospheric Administration (NOAA) recalculated climate data to correct for known biases and found that global warming had not paused as proponents of the hiatus theory had suggested.
In a study that was published in the prestigious journal Science, researchers from the National Oceanic and Atmospheric Administration wrote that Earth's global average surface temperature had climbed 0.2 of a degree Fahrenheit each decade since 1950, without interruption, due to the heat-trapping effects of greenhouse gases. This had also negated an awkward piece of evidence in the debate over whether human activity is indeed warming the planet.
Taking a detailed look at the study, the authors of the article stated that, Even putting aside possible artifacts in the temperature record, there is no substantive evidence of a pause or hiatus in warming. Now, a commentary article penned by several climate scientists and published this month in the journal Nature Climate Change, takes up a different side of NOAA s conclusion. The interpretation made by NOAA was not valid, said John Fyfe, a climate scientist at Environment and Climate Change Canada. The slowdown is there, even in this new updated data set .
Earlier, Judith Curry, a climatologist at Georgia Tech who argues that natural variability in climate cycles dominates the impact of industrial emissions and other human actions, had stated, I don't find this analysis at all convincing. While I'm sure this latest analysis from NOAA will be regarded as politically useful for the Obama administration, I don't regard it as a particularly useful contribution to our scientific understanding of what is going on.
However, there is a notable difference in Dr. Fyfe s choice of language and in the language used by global warming skeptics, Nature commentator Jeff Tolferson says.
Fyfe uses the term slowdown rather than hiatus and stresses that it does not in any way undermine global-warming theory .
Man-made global warming continues unchecked and the controversial warming hiatus revealed in 2013 didn't exist at all but was caused by skewed data.
Fyfe and his colleagues point out a mismatch between climate models predictions and actual observations, but stress that the data does not indicate that global warming reversed or even halted during that time, as has been suggested by the so-called hiatus theory. Fyfe said that he and his fellow authors believe that the Pacific Decadal Oscillation (PDO) was to blame for the slowdown since 2000. The Pacific Decadal Oscillation (PDO) is often described as a long-lived El Ni o-like pattern of Pacific climate variability (Zhang et al. 1997). As seen with the better-known El Ni o/Southern Oscillation (ENSO), extremes in the PDO pattern are marked by widespread variations in the Pacific Basin and the North American climate.
It's always good to go back and look at the data as carefully as possible and make sure it's calibrated correctly, said William Patzert, a climatologist at NASA's Jet Propulsion Laboratory in La Ca ada Flintridge. But the hiatus is history and it was real.
Hiatus controversy and beyond