From Stanford News Service:
MEDIA ADVISORY. Stanford at AGU Fall Meeting.
Global warming’s influence on extreme weather
Understanding the cause-and-effect relationship between global warming and record-breaking weather requires asking precisely the right questions.
Extreme climate and weather events such as record high temperatures, intense downpours and severe storm surges are becoming more common in many parts of the world. But because high-quality weather records go back only about 100 years, most scientists have been reluctant to say if global warming affected particular extreme events.
On Wednesday, Dec. 17, at the American Geophysical Union’s Fall Meeting in San Francisco, Noah Diffenbaugh, an associate professor of environmental Earth system science at the Stanford School of Earth Sciences, will discuss approaches to this challenge in a talk titled “Quantifying the Influence of Observed Global Warming on the Probability of Unprecedented Extreme Climate Events.” He will focus on weather events that – at the time they occur – are more extreme than any other event in the historical record.
Diffenbaugh emphasizes that asking precisely the right question is critical for finding the correct answer.
“The media are often focused on whether global warming caused a particular event,” said Diffenbaugh, who is a senior fellow at the Stanford Woods Institute for the Environment. “The more useful question for real-world decisions is: ‘Is the probability of a particular event statistically different now compared with a climate without human influence?'”
Diffenbaugh said the research requires three elements: a long record of climate observations; a large collection of climate model experiments that accurately simulate the observed variations in climate; and advanced statistical techniques to analyze both the observations and the climate models.
One research challenge involves having just a few decades or a century of high-quality weather data with which to make sense of events that might occur once every 1,000 or 10,000 years in a theoretical climate without human influence.
But decision makers need to appreciate the influence of global warming on extreme climate and weather events.
“If we look over the last decade in the United States, there have been more than 70 events that have each caused at least $1 billion in damage, and a number of those have been considerably more costly,” said Diffenbaugh. “Understanding whether the probability of those high-impact events has changed can help us to plan for future extreme events, and to value the costs and benefits of avoiding future global warming.”
Diffenbaugh’s talk takes place Dec. 17 at 2:44 p.m. PT in Room 3005 of Moscone West, Moscone Convention Center.
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But there has been no Global Warming for 18 years. Zero Global Warming cannot be responsible for anything. So I will say it again – this myth is BUSTED.
Ralph
Hope Anthony can stay awake or, better still, has a nice nap.
“Diffenbaugh said the research requires three elements: a long record of climate observations; a large collection of climate model experiments that accurately simulate the observed variations in climate; and advanced statistical techniques to analyze both the observations and the climate models.”
Rephrased for clarity:
Diffenbaugh said the fantasy requires three elements: a long record that does not exist; a large collection of computerized climate fantasies that accurately reflect the bias of the model creators; and enough mathematical hand waving to hide that there’s nothing real there.”
While the essence of this post deals with the relationship between so-called Global Warming and Extreme Weather, the connection has been disproven by many, Dr Madhav Khandekar, formerly of Environment Canada among them.
The larger question is whether changes in climate in general have any relationship to extreme weather occurrences. In that respect one should consider the dislocation and blocking patterns of zonal flow by meridional outbursts from so-called Polar Highs, which have become a regular feature at the end of the Solar Maximum that dominated the 20th century, as we are proceeding into a Solar Minimum regime. Mechanisms of this process (which, b.t.w. occurs in both hemispheres) have been described in various essays on Dr. Tim Ball’s website.
There have been unusually persistent outbursts of polar vortices, most noticeably in NH winters but equally present in the SH, as a correspondent in Cordoba, Argentina (30 degrees SL !) reports. But similar events during the summer period have also been reported (Urals to Pakistan blocking).
As the time period covering this solar change so far is relatively short, statistical evidence is meagre, so stay tuned.
For Open Access papers on the the direct and indirect solar cause of major climate changes, see the collection of more than a dozen papers in ‘Pattern Recognition in Physics’, Special Issue:
I have just been looking at temperatures in Denmark for each month and several years. It is very clear that the great variation is in the winter months where the temperature is lower. The same is seen in the Arctic, where the day to day variation can be 5K or more at winter times, which is never seen in the summer.
It somehow questions the meme of hotter weather beeing more extreme.
I believe the higher moisture in hot weather instead dampens the variability.
At Science 2.0 : “Weather Bombs, Polar Vortex: Global Warming’s Influence On Extreme Weather”, an article about the same press release states:
“Diffenbaugh emphasizes that asking precisely the right question is critical for finding the correct answer.”
Yes like asking “how many respondents in our survey who’s have written papers in the last X years on climate change and stand on one leg when they speak.” Would be an example of asking the right question to get the right answer — 97%
The anthropologist, Dr Brian Fagan, in his book The Little Ice Age, argues that seasonal variations are much more pronounced in a cooling world than a warming world based on his research. This makes sense in that there is more potential energy when the differences between the poles and equator increase (i.e. when the globe cools). During periods of global warming, the poles warm and the delta T between the equator and the poles decrease. The potential for extreme changes in seasonal weather decreases.
Dr. Diffenbaugh needs to read Dr. Brian Fagan’s book “The Little Ice Age.” Therein he will find mention of and references to the the severe North Sea Storms in the early 14th, Century which:
– carved out the Dutch Zeider Zee
– killed tens of thousands (!) of people
– ocurred in a time of global cooling…
He might change his mind when comparing all that to the relatively minor stuff which has ocurred over the last century.
Hmph: these modern keyboards just can’t spell!
Zuiderzee
There, got it right.