Tag Archives: El Nino

The Non-Trend In Hurricane Activity

18 Thursday Oct 2018

Posted by in Global Warming, Hurricanes

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People are unaccountably convinced that there is an upward trend in severe weather events due to global warming. But there is no upward trend in the data on either the frequency or severity of those events. Forget, for the moment, the ongoing debate about the true extent of climate warming. In fact, I’ll stipulate that warming has occurred over the past 40 years, though most of it was confined to the jump roughly coincident with two El Ninos in the 1990s; there’s been little if any discernible trend since. But what about the trend in severe weather? I’ve heard people insist that it is true, but a few strong hurricanes do not constitute a trend.

The two charts at the top of this post were created by hurricane expert Ryan N. Maue. I took them from an article by David Middleton., but visit Maue’s web site on tropical cyclone activity for more. The last month plotted is September 2018, so the charts do not account for Hurricane Michael and the 2018 totals are for a partial year. The first nine months of each year typically accounts for about 3/4 of annual tropical cyclones, so 2018 will be a fairly strong year. Nevertheless, the charts refute the contention that there has been an upward trend in tropical cyclone activity. In fact, in the lower chart, the years following the 1990s increase in global temperatures is shown to have been a time a lower cyclone energy. Roy Spencer weighs in on the negative trend in major landfalling hurricanes in the U.S. and Florida stretching over many decades.

Warren Meyer blames ‘”media selection bias” for the mistaken impression of dangerous trends that do not exist. That is, the news media are very likely to report extreme events, as they should, but they are very unlikely to report a paucity of extreme events, no matter how lengthy or unusual the dearth:

“Does anyone doubt that if we were having a record-heavy tornado season, this would be leading every newscast?  [But] if a record-heavy year is newsworthy, shouldn’t a record-light year be newsworthy as well?  Apparently not.” 

It so happens that 2018, thus far, has seen very close to a record low number of tornadoes in the U.S.

Meyer also highlights the frequent use of misleading statistics on the real value of damage from natural disasters. That aggregate value has almost certainly grown over the years, but it had nothing to do with the number or severity of natural disasters. Meyer explains:

“Think about places where there are large natural disasters in the US — two places that come to mind are California fires and coastal hurricanes. Do you really think that the total property value in California or on the US coastline has grown only at inflation? You not only have real estate price increases, but you have the value of new construction. The combination of these two is WAY over the 2-3% inflation rate.”

Recent experiences are always the most vivid in our minds. The same is true of broad impressions drawn from reports on the most recent natural disasters. The drama and tragedy of these events should never be minimized, and the fact that there is no upward trend in cyclone activity is no consolation to victims of those disasters. Still, the media can’t seem to resist the narrative that the threat of such events is increasing, even if it can’t be proven. Indeed, even if it’s not remotely correct. Reporters are human and generally not good at science, and they are not immune to the tendency to exaggerate the significance of events upon which they report. A dangerous, prospective trend is at once scary, exciting, and possibly career-enhancing. As for the public, sheer repetition is enough to convince most people that such a threat is undeniable… that everybody knows it… that the trend is already underway. The fact is that the upward trend in hurricane activity (and other kinds of severe weather) is speculative, not real.

Science of the Spurious: Global Warming and Suicide

27 Friday Jul 2018

Posted by in Global Warming

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The latest entry in the scare-mongering literature of global warming, published this month in Nature, purports to show that warming will lead to more suicides! I’m not sure whether these researchers deserve an award for naiveté or cynicism, but they should get one or the other. The lead author is listed as Marshall Burke of Stanford University.

The basic finding of their research is that an increase in average monthly temperature of one degree Celsius (1.8 degrees Fahrenheit) increases the monthly suicide rate by 0.68% (or 0.42% when accounting for the previous month’s temperature as well). They might have used the preferred verbiage “is associated with”, rather than “increases”, because they surely know that correlation is not the same as causation, but perhaps they wished to impress the news media. Let’s put their result in perspective: the annual U.S. suicide rate per 100,000 persons was 11.64 over the years 1968-2004 in their sample. A 0.68% increase in the suicide rate would have brought that up to roughly 11.72. Of course, the average U.S. surface temperature did NOT increase by 1 degree Celsius over that period — it was about half that, and temperatures have been relatively flat since then.

The real problem here is that most of the variation in temperatures across the sample used by Burke and his co-authors is seasonal and geographical. While they claim to have accounted for such confounding influences using non-parametric controls, they give few specifics, so I am unconvinced. It has long been known that suicides tend to be seasonal and are higher in the warmer months of the year. The reasons cited vary, including a boost provided by warmth in the energy needed to execute a suicide plan, “inflammatory chain reactions” from high pollen counts, seasonal peaks in bipolar disorder, and stress from greater social interactions during warm weather. These are seasonal phenomena that are not even incidental to the question at hand. And let’s face it: if warmer weather gives you the energy to kill yourself, the temperature is probably not the problem.

The authors also report a positive “effect” of temperatures on suicides using annual data, but with a rather large variance. This result probably captures geographical variation in suicide rates, though again, the authors claim to have made adjustments. Southern states tend have high suicide rates, but no one has suggested that warm, southern climates are to blame. Instead, there are other socioeconomic factors that probably account for this regional variation. I suspect that this is another source of the correlation the authors use to project forward as a likely impact of global warming. (While the inter-mountain West tends to have high suicide rates relative to other regions, many of those states are lightly populated, so they would receive low weights in any analysis of the kind discussed here.)

Finally, the trend toward slightly warmer temperatures between 1968 and the late 1990s was spurred largely by a series of strong El Nino events, especially in 1997-98. Suicide rates in the U.S., on the other hand, reached a high in the mid-1970s, ran slightly lower until hitting another peak in the mid-1980s, and then tapered through the late 1990s even as temperatures spiked. Since 1998, suicides have trended up as temperature trends flattened during the so-called “global warming hiatus”, which is ongoing. This sequence not only contradicts the authors narrative; it reinforces the fact that the variation exploited in the samples may well be seasonal and geographical, and not related to climate trends.

An issue over which Burke, et al demonstrate no awareness is the exaggerated statistical significance of meaningless effects in very large samples. This has been called the “p-value problem” because large samples can lead to vanishingly small p-values (which measure statistical significance). In a very large sample, any small difference may appear to be statistically significant. It’s a well-known pitfall in empirical work. A suicide is what’s known in the statistical literature as a “rare event”, given it’s annual incidence of about 0.01% of the population. I submit that the estimated impact of a 1% change in that rate, a change of 0.0001%, is well-nigh meaningless.

But the authors, undaunted, do their very best to make it seem meaningful. First, they pick a sub-sample that yields a somewhat higher estimated effect. Then they apply it to a future climate change scenario that is considered extreme and “extremely unlikely”, by climate researchers. They calculate the cumulative increase in suicides implied by that estimate out to 2050 — 32 years — for the U.S. and Mexico combined: about 22,000 extra suicides (they give a confidence interval of 9,000 to 39,000). That would be a lot, of course, but aggregating over many years using a high-end estimate and an extreme scenario can make an otherwise tiny effect appear large. And remember, their confidence interval is tightened considerably via the use of many observations on essentially irrelevant seasonal and geographic variation.

Burke and his co-authors have succeeded in publishing a piece of research that is not just flimsy, but that they apply in a way that is grossly misleading. They made it as ripe and plump as possible for promotion by the news media, which seems to love a great scare story. I might just as easily claim that as declines in income are associated with higher suicides, efforts at carbon mitigation requiring high taxes and punitive consumer rates for electric power will lead to an increase in suicides. And I could “prove” it with statistics. Then we would have a double-warming whammy! But I have a better idea: let’s expose bad research for what it is, and that includes just about all of the literature that warns of catastrophe from global warming.

Climate Change, Hurricanes and Noisy Statistics

22 Friday Sep 2017

Posted by in Global Warming

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The nasty spate of hurricanes this year has been a catch-up of sorts following a decade of subdued activity. In fact, global hurricane activity has been flat to declining in frequency since 1970. Until the recent increase, hurricane activity had been trending down in terms of 24-month cumulative energy since the 1990s, as the chart above shows. The historical data on the number of U.S. landfalls extends back to 1900, and it has had a negative trend as well. Nevertheless, we hear from climate alarmists that Hurricanes Harvey and Irma, which ended a drought of record length in U.S hurricane landfalls, and now presumably Maria, were a consequence of anthropomorphic global warming (AGW), er… climate change.

The implication is that increases in the atmospheric concentration of CO2 led to these hurricanes or their high intensity. Apparently, the paucity of hurricane activity over the previous ten years can be waved off as a fluke. A further implication of the alarmist view is that the longer negative trends in hurricane frequency and energy can be ignored in the context of any relation to CO2 concentration. But how so? One confounding factor I’ve seen mentioned blames El Nino warming in the Pacific, and a consequent increase in Atlantic wind shear, for the long lull in activity after 2005. That has a ring of plausibility, but a closer look reveals that actual El Nino activity during those years was hardly impressive, with the exception of 2015-16.

More historical data can be seen in the charts on the tropical cyclone page on the Watts Up With That? blog. (The charts in question start about two-thirds of the way down the page.) Hurricane expert Ryan Maue compiled a number of these charts, including the one above. He authored an editorial in the Wall Street Journal this week bemoaning the climate-change hype surrounding Harvey and Irma (if the link doesn’t work, it is available at the WSJ’s Opinion page on Facebook, posted on 9/17). Maue believes that both the climate science community and the media share in the blame for that hype. But he also says the following:

“Although a clear scientific consensus has emerged over the past decade that climate change influences hurricanes in the long run, its effect upon any individual storm is unclear.“

Maue provides a link to this NOAA web site offering cautious support for the proposition that there is a link between global warming and hurricane intensity, though the data it cites ends about ten years ago, so it does not capture the recent lull. Also, some of the information it provides is based on modeled global temperatures and hurricane activity through 2100. As is well-known by now, or should be, long-term climate forecasts based on carbon forcings are notoriously inaccurate, and NOAA admits that the association between those predicted temperatures and future hurricanes is tenuous:

“It is premature to conclude that human activities–and particularly greenhouse gas emissions that cause global warming–have already had a detectable impact on Atlantic hurricane or global tropical cyclone activity.“

Perhaps the idea that there is consensus regarding the relationship between climate change and hurricanes is more of a stretch than Maue and NOAA let on. Here is a summary of 30 peer-reviewed studies showing no connection to either hurricane frequency or intensity. Most of these studies are more recent than the end of the data record cited by NOAA. And in fact, many of these studies find support for a negative link between global temperatures and hurricane activity.

One of the prominent alarmists in the climate research community is Penn State’s Michael Mann, who has famously claimed that hurricanes are more frequent now than at any time in the past 1,000 years. He based his conclusions on highly speculative hurricane “proxies” identified in layers of sediment. Mann’s claims and research technique have been called into questioned by other climate scientists, who have arrived at contrary results in their own research. Lest anyone forget, Mann was implicated in a  data manipulation fraud related to the East Anglia climate scandal. Though cleared by a group of tenured professors at his own university, there are a number of climate scientists who believe Mann violated scientific standards.

The claim that global warming will cause hurricanes to become increasingly intense relies on elevated sea surface temperatures. This year, temperatures in the Gulf of Mexico are elevated and are said to have had a role in strengthening Harvey as it approached the Gulf Coast. Texas, however, has experienced as many landfalls of major hurricanes with cooler Gulf waters as with warmer waters. And Irma strengthened in a part of the Atlantic without such warm temperatures. Instead, minimal wind shear was implicated as a factor contributing to Irma’s strength.

In general, Atlantic temperatures have been relatively warm since the late 1990s, a fact that most scientists would at least partially attribute to the “Atlantic multi-decadal oscillation“, a regular cycle in water temperatures that repeats with a period of multiple decades. Potentially adding to that temperature increase is a controversial change in NOAA’s calibration of sea surface temperatures, as an increasing share of those readings are taken from buoys rather than ship-board measurement. There is some suspicion that NOAA’s adjustments “cool the past” more than is justified, a suspicion that was heightened by allegations from one whistle-blowing NOAA scientist early this year. Then, there is the contention that the sea surface temperature makes little difference if it is matched by an increase in air temperature.

Overall, NOAA says the combination of frequency and intensity of tropical cyclones will increase by 2%-11% over the rest of this century. As Roy Spencer notes, that is not a terribly alarming figure given the risks people have always willingly accepted by living in coastal areas. In any case, the range is based on models of climate behavior that are of questionable reliability. And like past temperature predictions produced by carbon-forcing climate models, it is likely to be a gross overestimate. Here is Roger Pielke, Sr., who is quoted in this wide-ranging post on hurricanes and climate at the Fabius Maximus web site:

“Model projections of hurricane frequency and intensity are based on climate models. However, none have shown skill at predicting past (as hindcasts) variations in hurricane activity (or long term change in their behavior) over years, decades, and longer periods. Thus, their claim of how they will change in the future remains, at most, a hypothesis (i.e. speculation). When NOAA, IPCC and others communicate to the media and public, to be scientifically honest, they should mention this.”

Despite the spike in activity this year, strong hurricanes are intermittent and fairly rare. Establishing reliable statistical connections with other forces is difficult with emergent events like hurricanes. Moreover, the degree of error in measuring global or regional temperature itself is much larger than is generally acknowledged, and the global warming “signal” is very weak. As we say in the statistical analysis business, noisy data are compatible with diverse hypotheses. The relationship between hurricanes and climate change is a prime example.

Record Hot Baloney

18 Sunday Jan 2015

Posted by in Global Warming

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It’s easy to make big headlines that serve a policy agenda when you can control the process generating “scientific” data. Here’s the latest in an ongoing fraud perpetrated by NASA, NOAA and a few other organizations. The disinformation is happily scooped up and reported by the unsuspecting news media, in this case The Wall Street Journal. The headline says that 2014 was the warmest year on record back to 1980, but there are several important respects in which the report from NASA and NOAA is misleading.

The surface temperature records maintained by NASA and NOAA (and others) utilize the same source data (despite NASA’s claim that the two series are “independent”), but they are heavily adjusted by the respective agencies. We can all probably agree that more recent temperature measurements (the raw data) are more reliable due to the availability of better and more numerous instruments (particularly for ocean surface temperatures). However, combining recent measurements with older data in a way that assures comparability is difficult over more than a few decades. Weather stations come, go, and relocate, environmental conditions around stations change with urbanization and airport expansions, and new measurement techniques are introduced.

Constructing a consistent temperature series over 130+ years at the world or regional level is therefore subject to much controversy. Here is a page with links to several good posts of the problems inherent in these efforts. Data is “infilled” and sometimes deleted, and statistical techniques are often applied in an effort to achieve consistency over time. However, it is curious that the NASA and NOAA adjustments over time seem to pivot around the levels of the 1950s and 1960s, as if to suggest that the temperatures measured in those decades are the most reliable part of the series. Take a look at the “gifs”in this post, which show temperatures before and after adjustments. An apparent consequence of the NASA / NOAA statistical techniques, which may seem even more curious to the casual observer, is that new observations can influence the entire temperature series. That is, adding 2014 temperatures to the series may lead to fresh downward adjustments to 1936 temperatures, if it suits the agencies. By the way, 1936 was a very warm year, but according to these agencies, it’s been getting less warm.

Another fascinating aspect of the report on 2014 temperatures is the obvious attempt to propagandize. This Bob Tisdale post sheds light on three serious omissions in the report and the related effort to “spin” the findings for the press:

1)  The range of uncertainty cited by NOAA in background documents indicates that the small margin (0.04 deg C for NOAA, 0.02 deg C by NASA) by which the reported 2014 global temperature exceeds the previous high is within the confidence interval around the previous high. By their own standard, it was “more unlikely than likely”that the 2014 temperature was the warmest on record, but that is not what the agencies report in their “Highlights.”

2) The report states that “This is the first time since 1990 the high temperature record was broken in the absence of El Niño conditions at any time during the year in the central and eastern equatorial Pacific Ocean….” Yet there were El Nino conditions elsewhere in the Pacific in 2014.

3) “NOAA failed to discuss the actual causes of the elevated global sea surface temperatures in 2014, while making it appear that there was a general warming of the surfaces of the global oceans.”

Tisdale notes elsewhere that the tiny margins of “record warmth” reported by NASA and NOAA contribute to a growing disparity between reported “actual temperatures” and those projected by climate warming models. The “Warmist” community will view the NASA / NOAA findings favorably, as the new “record high” supports their narrative,” providing new fodder for the agenda to end the use of fossil fuels and to regulate activities deemed “unsustainable.” Unfortunately, the misleading reports are likely to seem credible to the general public, which is largely ignorant of the agencies’ rampant manipulation of temperature data.

Hat Tip: Watts Up With That? and cartoonist Josh!