I haven’t seen Peterson et al (2013) presented alone yet at WattsUpWithThat. It was referred to in Jim Steele’s excellent WUWT post Fabricating Climate Doom – Part 3: Extreme Weather Extinctions Enron Style.
A who’s who of climatologists, including department heads, from numerous organizations around the United States contributed to Peterson et al (2013) Monitoring and Understanding Changes in Heat Waves, Cold Waves, Floods, and Droughts in the United States: State of Knowledge. Full paper here. The conclusions begin (my boldface):
Four key types of climate extremes (i.e., heat waves, cold waves, floods, and droughts) were assessed. The data indicate that over the last several decades heat waves are generally increasing, while cold waves are decreasing. While this is in keeping with expectations in a warming climate, decadal variations in the number of U.S. heat and cold waves do not correlate that closely with the warming observed over the United States. The drought years of the 1930s had the most heat waves, while the 1980s had the highest number of cold waves. River floods do not show uniform changes across the country; flood magnitudes as represented by trends in annual peak river flow have been decreasing in the Southwest, while flood magnitudes in the Northeast and north-central United States are increasing. Confounding the analysis of trends in flooding is multiyear and even multidecadal variability likely caused by both large-scale atmospheric circulation changes as well as basin-scale “memory” in the form of soil moisture. Droughts too have multiyear and longer variability. Instrumental data indicate that the Dust Bowl of the 1930s and the 1950s drought were the most widespread twentieth-century droughts in the United States, while tree ring data indicate that the megadroughts over the twelfth century exceeded anything in the twentieth century in both spatial extent and duration.
My Figure 1 is Figure 1 from Peterson et al (2013).
Figure 1
Its caption reads:
Fig. 1. Time series of decadal-average values of heat wave (red bars) and cold wave (blue bars) indices. These indices are a normalized (to an average value of 1.0) metric of the number of extreme temperature events for spells of 4-day duration. An event is considered extreme if the average temperature exceeds the threshold for a 1- in 5-yr recurrence. The calculations are based on a network of 711 long-term stations with less than 10% missing temperature values for the period 1895–2010. The horizontal labels give the beginning year of the decade. Recent decades tend to show an increase in the number of heat waves and a decrease in the number of cold waves but, over the long term, the drought years of the 1930s stand out as having the most heat waves. See the SM for details on the daily data used in this analysis and procedures used to calculate the indices.
And to confirm the discussion of drought from the conclusions above, Peterson et al (2013) presented their Figure 4, which I’ve included as my Figure 2.
Figure 2
Its caption reads:
Fig. 4. The percent area of the contiguous United States experiencing moderate to extreme drought [Palmer drought severity index (PDSI) ≤ –2.0] from January 1900 to October 2012 (red curve). Widespread persistent drought occurred in the 1930s (central and northern Great Plains, Northwest, and Midwest), 1950s (southern Great Plains and Southwest), 1980s (West and Southeast), and the first decade of the twenty-first century (West and Southeast). The dotted line is a linear regression over the period of record (linear trend = +0.09% decade–1), the solid line is for January 1931–October 2012 (–0.78% decade–1), and the dashed line is for January 1971–October 2012 (+3.70% decade–1).
Yet some members of the climate science community and the mainstream media continue to spin tall tales about weather growing more extreme in recent years. Nothing but nonsense.
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But, but, but its worse… Oh never mind.
When I see a graph like figure 4 what I see is there’s nothing unusual and natural variation is very large.
Thanks for the quick synopsis Bob.
For Fig 1, how did they select/establish 4-days as an event? Exceeding the statistical 5-year event counts as “extreme?” Maybe looking at temps is different than rainfall, but if i picked a 5-year 96-hour storm event to compare rain events to, I would have the engineering world puzzled.
That drought of the 1950s was vicious. My father was a small-town farm implement dealer in Texas at the time and it busted us. I grew up thinking land was supposed to have big cracks in it, and even today an approaching thunderstorm cheers me up.
Thanks Bob. Succinct and accessible as always. The agenda shines through and now the nonsense about Yosemite wild fires caused by climate change and threatening SF. It is a psychological war not scientific understanding
It seems the more the facts show them to be wrong, the more loudly the climate clowns bang the Alarmist drum, as if to try to drown them out. Here’s one doofus from UC Berkeley, an Anthony Barnosky who bloviates:
“Over the past few years, we’ve been seeing and living climate change,” he said, referring to extreme weather events and encroaching seas. “We’ve seen water pouring into the New York subway system.”
Barnosky also cited the 24,000 wildfires so far this year in the western U.S., along with heat waves and drought.
“Everybody’s experienced some climate change in the past few years,” he said. “What hasn’t happened yet is for that majority feeling, if you will, to percolate up to our political leaders. So I think we’re on the cusp of that being able to happen.”
http://blogs.kqed.org/science/audio/climate-scientist-to-politicians-its-time-to-face-the-facts/
One factor never mentioned as a contributor to floods in the North Central region is tile drainage on farms. Almost all farms in North America, particularly in comparatively flat country have installed tile drainage to accelerate spring runoff and to handle heavy rains. By definition, this is an enhancer of floods, speeding up the transfer of water from the catchment basin to the main rivers. It would be a nice trick if they could take the flood waters and transfer it down to TX-NM-AZ. Maybe a pipeline for water makes sense. Do you think Texas could use 9km^3 of water an hour?
http://en.wikipedia.org/wiki/Red_River_Floodway
> A Quick Note about Peterson et al (2013)
Wow, it really was a quick note. This must be a first for Bob. 🙂
One big problem I have with trying to look at climate trends with extreme weather is the relative paucity of the data compared to the day in, day out data that we have.
I track snowfall and “Snow Depth Days” at home and for several people in the northeast and have been struck by how incredibly noisy the data is. Not only does the data swing widely at each station from year to year, comparing stations yields surprising swings too. For example, my data near Concord NH is sometimes similar to Derry NH (about 30 miles SSE), but there are years when I’ve had much more and even a couple where snowfall was similar but SDDs (the snow depth for each summed together) were quite different. This is generally due to the storm track, but the early/late season timing of big storms comes into play too.
I’ll try to scrounge time to write a post about it before the snow season starts.
People can keep looking for a signal, e.g. disparity in soil moisture east and west of the Mississippi River, but I suspect most efforts like that will include data torture.
Once again the AGW promotion industry does not allow the lack of facts or data in support of their claim stand in the way of their chosen task.
Other contributors to flooding, in addition to tile drainage on farms, are destruction of wetland areas, paving over of (and other impervious building within) drainage areas, and the close management of rivers with systems of dams, levees, and dredged channels for shipping purposes. This is especially true in the Northeast, but also true in other parts of the country.
When people with some scientific knowledge write to project their fears onto the future, it is called science fiction.
We are warned that our behavior will push the planet past tipping points, which never happened in the past (or we would not be here), which are not happening now (all trends are within historical variability), but it is claimed the destruction will surely come in the future if we don’t do something now.
Classical science fiction mixed hopes in with the fears, imagining the possibilities as well as the dangers. But with climate science fiction, only doomsday scenarios are allowed.
Amazing, the slope of the increase since the 70’s is the same as that for the 1919 to 40 period, but the second is due to CO2 and the first can’t be by their theory. Such a perversion of science.
Good eye and thoughtful assessment of a paper’s conclusions, Bob Tisdale. Your points led to these thoughts:
1. To the extent that this paper came from historically accurate data (not created with the current doctored — fraudulently altered — “climate” data) and the study has integrity, who are these brave scientific souls? “A who’s who of climatologists, including department heads, from numerous organizations around the United States.” Apparently, they do not notice that warming has, at least, stalled; however, they do notice that there has been a warmer, drought-inducing American past. Bravo. I think they deserve some more individual notice from WUWT and other sources. In this way “alternative institutions”, like WUWT has become, are created. If universities and science organizations turn into fraudulent or religious institutions, then alternative organizations honoring the scientific method will carry science and historical accuracy forward. How to continue to spread, communicate, these truths becomes important.
2. “Suffering drought” should be an experience of the past. At the very least, in the U.S., we have both the knowledge of shifting climate patterns and the wealth (I am thinking of “potential” energy-development wealth, not wealth from the past) plus technology to pipe, or send by other means, water where it is needed when it is needed. New, inexpensive desalinization processes could protect coastal areas from drought. Furthermore, flooded sections of the country could develop pathways for that water to be diverted to where it is currently needed, or to major aquifers, or to the ocean. (I don’t mean to ignore the regional life-giving aspects of flooded land, e.g., renewal of soil, etc.)
3. By identifying those scientists with integrity and communicating the truths they put forward, we might be able to turn to thoughts of life and prosperity: both CO2 and water as basic elements of abundant human (and other) life. When the religious or authoritarian ones yell “drought” as if the sky was falling and their magic wands are desperately needed, we might calmly show that drought as a human calamity can “easily” be ended. As always, thank you, Anthony and colleagues.
The data indicate that over the last several decades heat waves are generally increasing, while cold waves are decreasing.
==================
If one looks at fig 1 it is obvious that this trend only occurs if one limits the analysis to the last several decades. if one looks at the full set of data, then the trend disappears. If anything the long term trend on fig 1 shows there has been no significant climate change in the US for the past 100 years, or perhaps even a slight cooling.
Any statistician can tell you that a trend that depends on the choice of end points is not a true trend. It is an artifact of the selection method. If anything, the obvious mathematical mistake in the conclusion demonstrates the lack of mathematical skill of a “who’s who of climatologists, including department heads, from numerous organizations around the United States”
More likely the end points in the conclusion were purposely chosen to be consistent with the assumption of recent warming, knowing full well that the longer term data did not support the conclusion. In other words, the scientists involved knowingly told a “fib” so that their report would be politically correct.
There was a time when we used to shake our heads in wonder at the Soviet Union for its politically correct science and the devastation it caused. How could such a thing happen we would ask. All the while feeling smug and secure in the knowledge that it could never happen here. Our system was so much superior, our freedom of speech guaranteed we would quickly uncover such errors before they did any harm.
Extreme weather. I noticed the 2014 AMS Annual Meeting was so themed. With little else.
How come no graphs on “perfect” weather trends? Don’t tell me we can’t find perfectspots! These damned spots are the most skittish bunch of entities I have ever seen.
Bob (or anyone), could you please comment on this issue? I’ve been under the impression that the CO2-based AGW hypothesis generally asserts that a warming will disproportionately occur in the higher latitudes. Is that right?
If so, the relative difference in temperatures between the tropics and the poles should be reduced, which should reduce overall atmospheric and oceanic convection, the primary driver of jet streams, trade winds and ocean currents, which are themselves the primary drivers of natural oscillations, both long term and short term. Is that a fair representation?
If CO2-based warming causes a loss of global convection, should not the incidence and intensity of extreme weather also be reduced, and ocean and atmospheric waming patterns become more consistent, with less variability?
By my eyes, droughts seem less likely during periods of warming.
The summary note is:
decadal variations do not correlate,
weather keeps moving around
Confounding the analysis of trends
many historical periods of extremes exceeded anything in the 20th Century
Good grief.
The only real trend coming from all of the monitoring of all things is the trend of increased imaginary or fabricated trends.
Why don’t they just conclude that all of the random and moving variability making it impossible to detect real trends is a new chaos humans have created.
AER can replace AGW.
Anthropogenic Elusive Radnomness
“The data indicate that over the last several decades heat waves are generally increasing, while cold waves are decreasing.”
But “last several decades” might be within one PDO state event, and not comparing it to the opposing state.
But, but…that’s not what UCS claims!
http://news.yahoo.com/climate-disinformation-continues-harm-u-communities-op-ed-183859532.html
“This summer’s heat has been brutal. A surprisingly early June heatwave broke records in the western United States. The heat sent people to emergency rooms and stoked wildfires that destroyed homes and lives. Wildfire season in the West — fueled by extreme heat and water stress — is now nearly two months longer than in the 1970s. Europe and Asia recently suffered dangerous heat waves, too.
Extreme events like these are becoming more common”
Putting out misinformation by claiming others are doing it. So tacky
Steve, that is perfect. We see what we want to see. AGWers look for terrible things and find them. No one is looking for perfect weather extremes. But what if increased CO2 correlates with perfect trends?
How does drought correlate with PDO?
It seems to me that weather is a function of the jet stream and regions of high and low pressure, on a hemispherical scale. These might be phenomenologically related, I’m not a meteorologist or a climate scientist.
To attribute changes in the occurrences of extreme weather events to increasing concentrations of CO2 in the atmosphere, it would seem that a connection between changes in CO2 concentrations and changes in the jet stream and high and low pressures. Thus this would seem to require demonstrations of a higher-order chain of connections of change: change in CO2 concentrations have directly caused changes in the jet stream and high and low pressure and these in turn have caused changes in weather and these in turn have caused changes in occurrences of extreme weather events.
I think the signal would be lost in the noise long before you get to the end of the chain. Not the least problem being that weather is very likely chaotic, making detection of the causes of change difficult. Especially difficult when thine scales of a few days are the focus.
All this begs the question of how single extreme weather events, on the order of days, can be related to climate, the latter being defined as some kind of average of weather over long periods of time, on the order of a few decades.
Generally, changes in the state of the sub-systems internal to the earth’s climate system are driven by gradients of the driving potentials for mass, momentum, energy, chemical and biological change. It is possible for the gradients to remain the same while changes occur in, say, the overall level of the temperature of the climate system. Gradients in the driving potentials will always and forever be present internal to the earth’s climate system. Thermal, mechanical, chemical and biological equilibrium between, and within, sub-systems will never be obtained. The gradients drive life.
Corrections for incorrectos will be appreciated
Mickey Reno: You’re not alone with your thoughts. I’ve seen that argument expressed many times. Polar amplification should reduce the temperature difference (absolute) between the tropics and the poles, and weather events, like tornados, that are tied to the temperature differences should decrease.
aaron says: “How does drought correlate with PDO?”
Refer to the following TAMU discussion for PDO correlation with temperature and precipitation. They also discuss the combined influences of the AMO and PDO on weather in the U.S.:
http://oceanworld.tamu.edu/resources/oceanography-book/oceananddrought.html
Regards