Excuse #64 For The ‘Pause’ In Global Warming: It’s Pure Luck

By Michael Bastasch Published: January 30, 2015

Scientists have a new explanation for why advanced climate models failed to predict the so-called “pause” in global warming: it’s just a happy coincidence — the 64th explanation for why the world hasn’t warmed like the models predicted.

A recent study by German-based scientists argue that luck, not systematic modelling errors, is why climate models failed to predict 15 years of flat global surface temperatures and more than 18 years of no warming in the lower atmosphere.

“We knew that the surface temperature of the earth has been stagnant for 15 years, whereas the models show progressive warming,” Jochem Marotzke, director of Germany’s Max Planck Institute for Meteorology, told the newspaper Deutsche Welle.

“We just wanted to grasp where this discrepancy between models and observations is coming from,” Marotzke said when explaining why he and fellow researchers conducted the study.

Marotzke’s claim that luck is the reason why climate models could not predict the pause in warming is just one of dozens of explanations given by scientists. This new study means there are now some 64 explanations for why the world has stopped warming in the past 15 to 20 years, according to those skeptical of global warming who keep track of the issue.

Climate scientists have been struggling to explain why global temperatures stopped their upward trend in the late 1990s. Some have argued it’s because of natural ocean cycles that have a cooling effect on the planet. Others argue it’s because of declining solar activity and that the world is set for global cooling.

Some have even argued small volcanic eruptions have caused global temperatures to flat-line.

“The fact that these volcanic signatures are apparent in multiple independently measured climate variables really supports the idea that they are influencing climate in spite of their moderate size,” said Mark Zelinka, a scientist at the Lawrence Livermore National Laboratory.

Satellite temperature records, which measure the lowest few miles of the atmosphere, show there has been no warming trend in the past 18 years and three months. This data also shows the warming trend was vastly overestimated by climate models.

Satellites show that warming since 1900 has only been 0.8 degrees Celsius per century, far lower than the 2.8 degrees of warming per century predicted by the Intergovernmental Panel on Climate Change in 1990.

Meteorological agencies tend not to use satellite data when calculating global temperature, instead relying on surface temperature readings from weather stations and ocean buoys across the world. But even surface temperatures show a lack of warming for the last 15 years or so, despite 2014 being declared the warmest year on record by government climate agencies.

“As meteorologists, we know that chance and chaos dominate the weather. You have to face the fact that chance plays a big role here,” Marotzke said. “It’s important that you can clearly distinguish between what happens randomly and what can be explained – which also improves our models.”

[h/t The Lid]

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