3 stories ..
#1 Study Claiming Insect Decline Due To Global Warming Is Based On Faulty Temperature Data.
By Paul Homewood
h/t Joe Public/Dave Ward
Many thanks to some real Sherlock Holmes work by Joe and Dave.
The article refers to this study by Brad Lister last year:
Arthropods, invertebrates including insects that have external skeletons, are declining at an alarming rate. While the tropics harbor the majority of arthropod species, little is known about trends in their abundance. We compared arthropod biomass in Puerto Rico’s Luquillo rainforest with data taken during the 1970s and found that biomass had fallen 10 to 60 times. Our analyses revealed synchronous declines in the lizards, frogs, and birds that eat arthropods. Over the past 30 years, forest temperatures have risen 2.0 °C, and our study indicates that climate warming is the driving force behind the collapse of the forest’s food web. If supported by further research, the impact of climate change on tropical ecosystems may be much greater than currently anticipated.
A number of studies indicate that tropical arthropods should be particularly vulnerable to climate warming. If these predictions are realized, climate warming may have a more profound impact on the functioning and diversity of tropical forests than currently anticipated. Although arthropods comprise over two-thirds of terrestrial species, information on their abundance and extinction rates in tropical habitats is severely limited. Here we analyze data on arthropod and insectivore abundances taken between 1976 and 2012 at two midelevation habitats in Puerto Rico’s Luquillo rainforest. During this time, mean maximum temperatures have risen by 2.0 °C. Using the same study area and methods employed by Lister in the 1970s, we discovered that the dry weight biomass of arthropods captured in sweep samples had declined 4 to 8 times, and 30 to 60 times in sticky traps. Analysis of long-term data on canopy arthropods and walking sticks taken as part of the Luquillo Long-Term Ecological Research program revealed sustained declines in abundance over two decades, as well as negative regressions of abundance on mean maximum temperatures. We also document parallel decreases in Luquillo’s insectivorous lizards, frogs, and birds. While El Niño/Southern Oscillation influences the abundance of forest arthropods, climate warming is the major driver of reductions in arthropod abundance, indirectly precipitating a bottom-up trophic cascade and consequent collapse of the forest food web.
Sounds like an open and shut case eh?
Lister even adds these temperature graphs to his paper:
Given that, as the paper itself admits, warming in the tropics in theory should be much less than elsewhere, claims of a 2C increase since the 1970s did not pass the sniff test. Fortunately Joe Public decided to go away and check the actual data used by Lister.
His findings should alarm anybody who believes in the integrity of science and peer review.
Let’s take a closer look at those graphs.
All the temperature data used comes from just two sites, El Verde and Bisley (not Bisely). But Bisley data only begins in 1993, so the comparisons with the 1970s rely solely on El Verde, the data for which is sourced from here.
And this is what the Station Metadata has to say:
In short, the data Lister uses prior to 1992 is worthless, and were substantially understated in comparison with those that followed.
If we begin the chart in 1992, we find that temperatures have actually been dropping, and not increasing.
The metadata states that temperatures showed an abrupt increase in 1997, as the adjustments were ended. However, this step up is not apparent on Lister’s graph. Rather, the step up is in 1992. This seems to indicate that Lister uses the unadjusted data.
The metadata also links to the dataset:
And this provides some handy graphs.
Below is the chart of annual temperatures from 1993 to 2013. [The data only runs to Feb 2014]
This shows the same pattern of declining temperatures since 1992. We know that the data since 1997 is fully reliable, and this too shows a declining trend. Note too that Lister’s graph indicates temperatures since 2013 have been lower still for three of the last four years.
This still leaves us the problem of Bisley, where data starts in Feb 1993. CLIMDB only have data till Nov 2010, so full annuals are only available from 1994 to 2009:
For some reason, Bisley shows a rather different picture to El Verde, although there is no obvious warming trend. Given that El Verde and Bisley are only a few miles apart, it is obvious that the divergence between the two is due to dodgy data and not real.
To sum up, we have a paper which makes bold claims that arthropods have been declining at an alarming rate since the 1970s, and that the cause is climate warming.
Yet these claims are based on long term temperature data, which, according to the organisation that actually maintains the data, is not reliable and should not be used for long term trends.
The only reliable data covers the period since 1992, and this shows declining temperatures. Even this dataset is not consistent with the Bisley one.
Clearly the whole study is worthless, and the paper should be withdrawn.
There are some alarming facts about all of this:
1) Why did the researchers not suspect that the temperature data looked hopelessly wrong at the outset?
2) Why did peer review not do the basic checks that I did?
3) The study carries out some mindbendingly complex statistical analysis, linking arthropod decline to rising temperatures. But how can this analysis have been robust, when the temperature data was hopelessly wrong?
The conclusion is that the faulty temperature data matched the researchers’ expectations of climate warming, and consequently they never bothered to crosscheck. It would after all have been extremely simple to have asked the people who maintain the data.
Whether or not arthropods are in decline I have no idea. But by blaming non existent climate warming, there is a very real danger that the true cause is being missed. Indeed, looking at those graphs, it may well be climate cooling that is responsible.
I plan to contact PNAS, who published the paper, to request that it be withdrawn.
# 2 Climatologist: Oceans Warming Reports ‘Greatly Exaggerated’
By Roy W Spencer PhD
Summary: The recently reported upward adjustment in the 1971-2010 Ocean Heat Content (OHC) increase compared to the last official estimate from the IPCC is actually 11%, not 40%.
The 40% increase turns out to be relative to the average of various OHC estimates the IPCC addressed in their 2013 report, most of which were rejected.
Curiously, the new estimate is almost identical to the average of 33 CMIP climate models, yet the models themselves range over a factor of 8 in their rates of ocean warming.
Also curious is the warmth-enhancing nature of temperature adjustments over the years from surface thermometers, radiosondes, satellites, and now ocean heat content, with virtually all data adjustments leading to more warming rather than less.
I’ve been trying to make sense out of the recent Science paper by Cheng et al. entitled How Fast are the Oceans Warming? The media headlines I saw that jumped out at me (and several others who asked me about them) were:
World’s Oceans Warming 40% Faster than Previously Thought (EcoWatch.com),
For those who read the paper, let me warn you: The paper itself does not have enough information to figure out what the authors did, but the Supplementary Materials for the paper provide some of what is needed.
I suspect this is due to editorial requirements by Science to make articles interesting without excessive fact mongering.
One of the conclusions of the paper is that Ocean Heat Content (OHC) has been rising more rapidly in the last couple decades than in previous decades, but this is not a new finding, and I will not discuss it further here.
Of more concern is the implication that this paper introduces some new OHC dataset that significantly increases our previous estimates of how much the oceans have been warming.
As far as I can tell, this is not the case.
Dazed and Confused
Most of the paper deals with just how much the global oceans from the surface to 2,000 m depth warmed during the period 1971-2010 (40 years) which was also a key period in the IPCC 5th Assessment Report (AR5).
And here’s where things get confusing, and I wasted hours figuring out how they got their numbers because the authors did not provide sufficient information.
Part of the confusion comes from the insistence of the climate community on reporting ocean warming in energy content units of zettajoules (a zettajoule is 1,000,000,000,000,000,000,000 joules, which is a billion trillion joules… also a sextillion joules, but male authors fear calling it that), rather than in what is actually measured (degrees).
This leads to confusion because almost nowhere is it ever stated what the assumed area of ocean was used in the computation of OHC (which is proportional to both temperature change and the volume of seawater involved in that temperature change).
I’ve looked in this paper and other papers (including Levitus), and only in the 2013 IPCC report (AR5) did I find the value 3.6 x 10^14 square meters given for ocean area. (Just because we know the area of the global oceans doesn’t mean that is what is monitored, or what was used in the computation of OHC).
Causing still further confusion is that Cheng et al. then (apparently) take the ocean area and normalize it by the entire area of the Earth, scaling all of their computed heat fluxes by 0.7.
I have no idea why, since their paper does not deal with the small increase in heat content of the land areas. This is just plain sloppy because it complicates and adds uncertainty when others try to replicate their work.
It also raises the question of why energy content? We don’t do that for the atmosphere. Instead, we use what is measured — degrees.
The only reason I can think of is that the ocean temperature changes involved are exceedingly tiny, either hundredths or thousandths of a degree C, depending upon what ocean layer is involved and over what time period.
Such tiny changes would not generate the alarm that a billion-trillion joules would (or the even scarier Hiroshima bomb-equivalents).
But I digress.
I think I finally figured out what Cheng et al. did (thanks mostly to finding the supporting data posted at Cheng’s website).
The “40%” headlines derive from this portion of the single figure in their paper, where I have added in red information which is either contained in the Supplementary Materials (3-letter dataset IDs from the authors’ names) or are my own annotations:
The five different estimates of 40-year average ocean heating rates from the AR5 report (gray bars) are around 40% below the newer estimates (blue bars), but the AR5 report did not actually use these five in their estimation — they ended up using only the highest of these (Domingues et al., 2008).
As Cheng mentions, the pertinent section of the IPCC report is the “Observations: Oceans” section of Working Group 1, specifically Box 3.1, which contains the numerical facts one can fact-monger with.
From the discussion in Box 3.1, one can compute that the AR5-estimated energy accumulation rate in the 0-2000 m ocean layer (NOT adjusted for total area of the Earth) during 1971-2010 corresponds to an energy flux of 0.50 Watts per sq. meter.
This can then be compared to newer estimates computed from Cheng’s website data (which is stated to be the data used in the Science study) of 0.52 W/m2 (DOM), 0.51 W/m2 (ISH), and 0.555 W/m2 (CHG).
Significantly, even if we use the highest of these estimates (Cheng’s own dataset) we only get an 11% increase above what the IPCC claimed in 2013 — not 40%.
Agreement Between Models and Observations
Cheng’s website also contains the yearly 0-2,000m OHC data from 33 CMIP5 models, from which I calculated the average warming rate, getting 0.549 W/m2 (again, not scaled by 0.7 to get a whole-Earth value).
This is amazingly close to Cheng’s 0.555 W/m2 he gets from reanalysis of the deep-ocean temperature data.
This is pointed to as evidence that observations support the climate models which, in turn, are of course the basis for proposed energy policy changes and CO2 emissions reduction.
How good is that multi-model warming rate? Let me quote the Science article (again, these numbers are scaled by 0.7):
“The ensemble average of the models has a linear ocean warming trend of 0.39 +/- 0.07 W/m2 for the upper 2,000 m from 1971-2010 compared with recent observations ranging from 0.36 to 0.39 W/m2.”
See that +/- 0.07 error bar on the model warming rate? That is not a confidence interval on the warming rate. It’s the estimated error in the fit of a regression line to the 33-model average warming trace during 1971-2010. It says nothing about how confident we are in the warming rate or even the range of warming rates BETWEEN models.
And that variation between the models is where things REALLY get interesting. Here’s what those 33 models’ OHC warming profiles look like, relative to the beginning of the period (1971), which shows that they range over a factor of 8X (from 0.11 W/m2 to 0.92 W/m2) for the period 1971-2010!
What do we make of a near-perfect level of agreement (between Cheng’s reanalysis of OHC warming from observational data and the average of 33 climate models) when those models themselves disagree with each other by up to a factor of 8 (700%)?
That is a remarkable stroke of luck.
It’s Always Worse than We Thought
It is also remarkable how virtually every observational dataset — whether (1) surface temperature from thermometers, (2) deep-ocean temperature measurements, atmospheric temperature from (3) satellites, and from (4) radiosondes, when reanalyzed for the same period, always end up with more (not less) warming?
What are the chances of this? It’s like flipping a coin and almost always getting heads.
Again, a remarkable stroke of luck.
Read more at Roy Spencer’s Blog
# 3 Rapid Sea Level Rise Was Supposed To Shrink Earth’s Coasts. It Hasn’t
By Kenneth Richard
“Over the past decades, atoll islands exhibited no widespread sign of physical destabilization in the face of sea-level rise.
“88.6% of islands were either stable or increased in area, while only 11.4% contracted.
“It is noteworthy that no island larger than 10 has decreased in size.
These results show that atoll and island areal stability is a global trend, whatever the rate of sea-level rise.”- Duvat, 2019
I. Despite sea level rise, “the coasts are growing all over the world”
Sea levels aren’t rising fast enough to deleteriously affect coastal areas on a net global scale.
Satellite observations indicate there have been 13,565 km2 of net growth in the land area across the globe’s coasts between 1985-2015.
In other words, the Earth’s coasts gained more land area then were lost to rising sea levels.
“Earth’s surface gained 115,000 km2 of water and 173,000 km2 of land over the past 30 years, including 20,135 km2 of water and 33,700 km2 of land in coastal areas.” (Donchyts et al., 2016)
As a visual example, Ahmed et al. (2018) find that Bangladesh’s coastal land area grew by 7.9 km2 per year during 1985-2015.
“This paper draws upon the application of GIS and remote sensing techniques to investigate the dynamic nature and management aspects of land in the coastal areas of Bangladesh. … This research reveals that the rate of accretion [coastal land growth] in the study area is slightly higher than the rate of erosion. Overall land dynamics indicate a net gain of 237 km2 (7.9 km2annual average) of land in the area for the whole period from 1985 to 2015.” (Ahmed et al., 2018)
Image Source: Ahmed et al., 2018
II. Even with ~4 mm yr−1 local sea level rise, Pacific islands grew in size during 1971-2014
Between 1958-2014, the globe’s sea levels rose at a rate of about 1.4 mm yr−1 , or 14 centimeters (5.5 inches) per century (Frederikse et al., 2018).
Ice melt from Greenland and Antarctica contributed a grand total of 1.5 cm of the 7.9 cm (3.1 inches) of sea level rise during those 56 years.
“The global-mean sea level reconstruction shows a trend of 1.5 ± 0.2 mm yr−1 over 1958–2014 (1σ), compared to 1.3 ± 0.1 mm yr−1 for the sum of contributors.” (Frederikse et al., 2018)
However, there are regions of the world where sea levels are rising at rates two or three times the global average.
Tuvalu, representing over 100 islands located in the central west Pacific, has undergone “twice the global average” rate of sea level rise (~3.90 ± 0.4 mm yr−1) since the 1970s.
It would be expected that such high rates of local sea level change would result in shrinking island coasts and overall land area during this period.
But the opposite has occurred. There has been a net increase in the coastal land area of Tuvalu between 1971-2014 in 8 of 9 atolls.
“We specifically examine spatial differences in island behaviour, of all 101 islands in Tuvalu, over the past four decades (1971–2014), a period in which local sea level has risen at twice the global average. Surprisingly, we show that all islands have changed and that the dominant mode of change has been island expansion, which has increased the land area of the nation.”
“Using remotely sensed data, change is analysed over the past four decades, a period when local sea level has risen at twice the global average (~3.90 ± 0.4 mm yr−1). Results highlight a net increase in land area in Tuvalu of 73.5 ha (2.9%), despite sea-level rise, and land area increase in eight of nine atolls.” (Kench et al., 2018)
III. The stability or coastal net growth of islands in recent decades to century “is a global trend”
Coastal stability and expansion for atoll and island land area is not just a regional trend, but a global one.
A comprehensive (709 islands) review of coastal changes that have been observed in the last decades to this century (Duvat, 2019) reveals that no atoll island destabilization has occurred due to the effects of rising sea levels.
In fact, 88.6% of the globe’s islands have coasts that are either stable or expanding in size.
Further, not a single island larger than 10 hectares [1 ha = 10,000 square m, or 2.5 acres] has decreased in size in recent decades.
None of these observed trends affirm the popularized claim that modern sea level rise is currently threatening the globe’s coasts.
Read rest at No Tricks Zone
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