Sunday, 21 April 2013

zonder titel


Thursday, 18 April 2013

Belgian climate pseudo skeptics address ten issues, score zero goals. Or how to disagree with yourself !

The global warming policy foundation, a British astroturf group unwilling to disclose its funding, published an article of four Belgian climate pseudo-skeptics: Istvàn Marko, Alain Préat, Samuele Furfari and Henri Masson.

The article starts with complaining they don’t get the attention they want in the very biased media.
There are lot of internetsites full of climate skepticism, but in the scientific press this skepticism evaporates:
Peer reciew

Research has shown there is a strong misrepresentation in the media. But not in the way the gang of four claims, contrary: pseudo skeptics receive much more media-attention than they deserve !

The number of peer review articles related to climate change written by the four Belgians: exactly zero.

If they want more media attention, there’s a solution: maybe they might start with … contributing to this scientific topic. Giving a presentation is not enough to do science. Especially when the presentation is very substandard

Their GWPF-article continues with ten points of which they claim they rebut climate science. This is not true, and actually the ten points are often the opposite of what the very same people said elsewhere. yes you read it right: they themselves have rebutted several of the ten points of 'evidence' they present.


Check this out:
1. The climate has always changed. This was true during ancient times and it has also been true since the beginning of the modern era. These climate changes have always been, and still are, independent of the concentration of CO2 in the atmosphere;
A rather strange point if you ask me, as nobody claims it never changed. And an incorrect one. There are several reasons why climate can change (Milankovic cycles p.ex.), but CO2 always has been one of the components influencing earth's temperature. Of course it has, physical laws have been the same back then as.

The Vostok ice-cores clearly show that, contrary to what they write, in the past there *has* been a correlation between CO2 and temperature.

Vostok ice core
Vostok Ice Core: CO2 and Temperature


Actually, in the same text, they do refer to this Vostok-core. So they are aware themselves there's a correlation between CO2 and earth's climate. So their 10 points aren't very consistent...

Remarkably, Istvàn Marko agrees CO2 is a greenhouse gas: "Le CO² est considéré comme étant l’un des principaux responsables de l’effet de serre et il est impératif de réduire sa concentration dans l’air."

In English: ”CO2 is considered to be one of the main causes of the greenhouse effect and it's absolute necessary to reduce the atmospheric concentrations of CO2".

In other words: Marko himself disagrees with the GWPF-text he signed.

2. During Roman times and the Middle Ages temperatures were observed well in excess of those currently experienced. From the 16th till the 19th century a cold period referred to as the “Little Ice Age” predominated. All these changes took place without mankind being held responsible. We believe that the increase in temperatures that occurred during a certain part of the 20th century is the result of a recovery from this cold period. These various events can be explained by a combination of warm and cold cycles of different magnitudes and duration. Why and how this happens is not yet fully understood, but some plausible explanations can be put forward;
This a non sequitur. A non-influence in the past, doesn't automatically mean present day climate cannot be influenced by mankind.

A nice analogy is the forest-fire one: even though this kind of fires occurs naturally, this does not imply a pyromaniac cannot burn down a forest.

Earth's atmosphere contained no free oxygen during the first billion years or so. Free oxygen only emerged in the atmosphere as a *result* of ....life on earth ! That's how dramatic the influence of life can be on our planet's atmosphere.

If we look at the anthropogenic impact on the atmosphere, we see that, just like other species have done before, we are altering earth's atmosphere:

anthropogenic rise greenhouse gasses
Anthropogenic rise of some greenhouse gasses

The graph clearly demonstrates man *significantly* altered the concentration of several greenhouse gasses in the atmosphere.

3. The so-called “abnormally rapid” increase in global temperatures between 1980 and 2000 is not unusual at all. There have in fact been several such periods in the past, during which temperatures rose in a similar manner and at comparable rates, even though fossil fuels were not yet in use;
A non sequitur similar as the one above. The pyrmonaniac still burned down the forest.

4. Temperature measurements do not necessarily correlate with a building up or a decrease in heat since heat variations are energy changes subject to thermal inertia. Apart from heat many other parameters have an influence on temperature. Moreover the measurement of temperatures is subject to numerous large errors. When the magnitude and plurality of these measurement errors are taken into account, the reported increase in temperatures is no longer statistically significant;
Oddy Alain Préat stated the following in this presentation (p. 37):

"Réchaufement modeste mais INDISCUTABLE de 0,4 à 0,6 °C depuis le début du XXème siècle"

Or in English: "there's a small but INDISPUTABLE heating (his emphasis !!!!) of 0,4 to 0,6 °C since the beginning of the 20th century".

Again, one of the authors disagrees with what's written in the GWPF-article....

5. The famous “Hockey-stick” curve, known as the Mann’s curve and presented six times by the IPCC in its penultimate report, is the result among other things of a mistake in the statistical calculations and an incorrect choice of temperature indicators, i.e. proxies. This lack of scientific rigour has totally discredited the curve and it was withdrawn, without any explanation, from subsequent IPCC reports;
There have been several temperature reconstructions since the original MBH99 paper, demonstrating the original paper, even though there were some statistical flaws, wasn't all that bad.
Do notice the conspiracy theory they launch between the lines stating 'withdrawn, without any explanation'.

Scientific knowledge increases, and it's just normal new reports look at the newest scientific body of evidence. This is the way it should.

On top of that, the statement is completely false, the AR4 clearly and explicitly discusses the problems with MBH99. On top of that the graph is still there. So apparently, none of the four authors actually read the IPCC report they are criticizing ?

Do have a look at the graph presented in the AR4. Are you able to spot the MBH99 one without looking at the legend ?
AR 4 hockeystick
AR4 Paleoreconstructions temperature

 6. Even though they look formidably complex, the theoretical models employed by the climate modellers are simplified to the extreme. In fact there are far too many (known and unknown) parameters that influence climate change. At the moment it is impossible to take them all into account. The climate system is extremely complex, containing not only chaotic components but also numerous positive and negative feedback loops operating according to various different time scales. Which is why the IPCC wrote in its reports that: “…long-term prediction of future climate states is not possible” (page 774, Third report). This is very true. To this day all the climate predictions based upon these models have turned out to be totally incorrect. Strangely, nobody seems to care;

They seem to be a bit confused here: the quote they use clearly says "climate states". And while yes this increases uncertainty (hey, no one ever said climate models are perfect) as there are feedback processes, this does not mean as they want to try to suggest, that it is impossible to make any predictions of the future.

Saying climate predictions based on models are totally incorrect is a false statement, as this skeptical science post demonstrates:
climate model versus reality
climate models versus  reality


The AR4 comes to this conclusion on the reliability of climate models:
"In summary, confidence in models comes from their physical basis, and their skill in representing observed climate and past climate changes. Models have proven to be extremely important tools for simulating and understanding climate, and there is considerable confidence that they are able to provide credible quantitative estimates of future climate change, particularly at larger scales. Models continue to have significant limitations, such as in their representation of clouds, which lead to uncertainties in the magnitude and timing, as well as regional details, of predicted climate change. Nevertheless, over several decades of model development, they have consistently provided a robust and unambiguous picture of significant climate warming in response to increasing greenhouse gases."
7. The relationship between CO2 and temperature, obtained from the Vostok ice cores, shows that a building up of CO2 occurs 800 to 1000 years after an increase in temperature is observed. Hence the increase in the concentration of CO2 is a consequence of the warming of the climate, not its cause;
Ah, another non sequitur. And one that is perfectly explained here
8. But the coup de grâce to the “warmists’ theory” – certainly not yet visible in the French and Belgian media – comes from the observation that for the past fifteen years or so the global temperature of the Earth has remained constant. During the same period CO2 emissions have increased by far more than in the past, reaching an unparalleled record this year. Honest climate scientists admit that this observation is an embarrassing inconvenience for their theory. However, attempts to make us believe that the Earth is continuing to warm up persist. Will we have to wait for another twenty, twenty-five or thirty years for the global warming advocates to finally admit that there is no unambiguous correlation between the global temperature of the Earth and human-generated CO2 emissions?
There's a lot of noise on a temperature, that's why you cannot use short terms to say *anything* about climate.

The WMO defines climate as the weather averaged over a 30 year period. Not shorter.
Alain Préat is aware of this: "Le climat est défini comme l’état moyen, sur une période d’au moins 30 ans" so it's a mystery why he is using a time period he knows to be too short.

On short time intervals other factors can mask the influence of the rise due to CO2. Especially the ENSO-phenomena, having a large influence on the distribution of the heat content between surface and
ocean.

The four authors do acknowledge there are several components influencing temperatures in their 4th point, so they should be aware it's not very useful to talk about the influence of CO2 on such a short time scale. So in my opinion, again, they are not being very consistent.

The ENSO index is shown in the image below
Enso index 2013
ENSO-index


When we look at both surface and ocean, it's clear there's no pause in the warming of the earth.
earth is not warming
No pause in the rise of earth's heat content

 
9. The claim that Hurricane Sandy is due to human CO2 emissions is totally unfounded and has been vigorously contested by numerous meteorologists. This regrettable distortion of the facts has been denounced in an open letter, addressed to the General Secretary of the UN and signed by more than 130 world-renowned scientists, including one of the present authors;
It's impossible to attribute a single extreme weather event to climate change. So attributing Sandy to global warming is nonsense.

Nevertheless predictions are there will be more severe storms, so more storms *like* Sandy.
10. Finally the “abnormal” melting of the Arctic Sea ice, that made the headlines of numerous journals during this summer, was also observed during previous decades. Amazingly the record high increase in Antarctic Sea ice that occurred at exactly the same time has been completely ignored by the very same media. Moreover, no mention has been made of the current, particularly rapid, regeneration of the Arctic Sea ice.
I'm not really which rapid regeneration of arctic sea ice they are talking: here are the arctic ice extents, as presented (p. 39) by ... Alain Préat István Markó

Arctic ice extent istvan marko


sea ice extent 2013
steady decline of the arctic sea-ice extent


I'm really not sure what rapid regeneration they are talking about... Once again, one of the four authors is debunking the GWPF-article. Unless they mean ice is growing in winter. Of course it is.
 
My conclusion is that the ten points they raise do not rebut climate science at all. And remarkably they often are in conflict with what the authors themselves said elsewhere. Implying there’s an odd and strong inconsistency in the entire article they’ve written for the GWPF.

jules

kudos to Sylvain for helping me with some of the references.

update: several typos corrected

Wednesday, 10 April 2013

Een koude winter ?

Nog al te vaak zie je mensen stellig beweren dat de opwarming van onze planeet moeilijk te verzoenen valt met de koude temperaturen die West-Europa afgelopen winter kende.
Nu is de planeet natuurlijk net dat tikkeltje groter dan enkel West-Europa, daarom kan het eens nuttig zijn te bekijken hoe de temperatuur de afgelopen maanden eigenlijk lagen ten opzichte van het gemiddelde:

201301
201302
De gegevens van NOAA maken het duidelijk: de koude in januari en februari was een lokààl fenomeen.
Wordt naar de mondiale gegevens gekeken, dan blijkt dat de zogenaamd koude februarimaand, in realiteit de 9de warmste februarimaand was sinds het begin van de metingen.
Dat is dan ook weer duidelijk.
Overigens zou de koude West-Europese winter paradoxaal genoeg wel eens een direct gevolg kunnen zijn van de smelt van arctisch ijs ten gevolge van … de opwarming van onze planeet.

Thursday, 4 April 2013

Papers bekritiseren die je niet eens gelezen hebt, Rypke Zeilmaker en Hans Labohm style

Recent ging er heel wat aandacht naar de paper A Reconstruction of Regional and Global Temperature for the Past 11,300 Years van Marcott et al die in Science werd gepubliceerd.

In de paper werd door gebruik van proxies een temperatuurreconstructie gemaakt van de voorbije 11 300 jaar. Het resultaat is onderstaande grafiek.
marcott-B-CD
Marcott et al. 2013
Zoals te verwachten viel, werd de paper onmiddellijk zwaar bekritiseerd door pseudoskeptici. Niet zozeer omwille van wetenschappelijke gronden, maar omdat het resultaat  van het onderzoek hen niet bevalt. De paper zou immers aantonen dat de temperaturen recent snel gestegen zijn. Wat overigens geen nieuws is natuurlijk.

Bij die stijging in bovenstaande grafiek moeten enige kanttekeningen geplaatst worden: het onderzoek gebeurde aan het de hand van proxies, d.w.z. indicatoren die verband houden met de temperaturen uit het verleden. Er waren immers in het verleden nog geen thermometers.

Een overzicht van de gebruikte proxies wordt weergegeven in de bijlagen van de paper.

De proxies beslaan niet het hele aardoppervlak, en uiteraard beslaan de individuele proxies ook niet de gehele tijdsspanne die wordt beschreven. Hierdoor zijn er uiteraard nog onzekerheidsmarges in de temperatuurreconstructie, maar desondanks vormt de reconstructie, de eerste in zijn soort die een dergelijke tijdsspannen beslaat, een behoorlijk accurate weergave van de temperaturen in het holoceen. De studie wijkt ook niet af van wat reeds bekend was.

De fuzz die in de blogosfeer is ontstaan gaat in wezen ook niet over de reconstrutie van de voorbije 11 000 jaar, maar concentreert  zich voornamelijk op de sterke stijging op het eind van de grafiek, waarbij bv. Steve McIntyre zijn uiterste best doet verwarring te zaaien bij de leek.

De kritiek op dit deel van de grafiek moet echter juist gekaderd worden: ze vormt niet de kern van het onderzoek. Door het beperkt aantal proxies dat gebruikt werd voor het eind van de grafiek, is het resultaat niet incorrect zoals her en der wordt beweert, maar ook niet bijzonder standvastig. Iets waar de auteurs zich overigens van bewust zijn, en wat ze zelf ook duidelijk aangeven.

Erg relevant is die onzekerheid niet, omdat we van de laatste honderdvijftig jaar uiteraard niet enkel afhaneklijk zijn van proxie-studies, maar gewoon beschikken over thermometergegevens. En die geven ondubbelzinnig aan dat de aarde in rap tempo aan het opwarmen is.

Interessant is hoe een bepaalde hoek in de blogosfeer nou plotsklaps beweert dat de studie ‘frauduleus’ of  op zijn minst ‘onwetenschappelijk’ zou zijn, omwille van de onzekerheid betreffende de stijging in het laatste deel van de grafiek. En waarbij pseudoskeptici claimen dat de auteurs dit zouden verzwegen hebben. Dit is een wel heel merkwaardige kritiek, omdat de auteurs die onzekerheid expliciet en ondubbelzinnig weergeven in hun paper:
However, considering the temporal resolution of our data set and the small number of records that cover this interval (Fig. 1G), this difference is probably not robust. Before this interval, the gap-filled and unfilled methods of calculating the stacks are nearly identical (Fig. 1D)
De conclusie is dan ook duidelijk; wie beweert dat de auteurs slecht werk hebben afgeleverd met betrekking tot het einddeel van de grafiek heeft…. de paper domweg nooit gelezen. Wat uiteraard te gek voor woorden is. Desondanks wordt de mythe over de ‘onjuistheid’ van het einddeel van de grafiek overal op het ineternet vlotjes gekopieerd. Waarbij schijnbaar niemand de moeite doet om te lezen wat er nou eigenlijk in de paper zelf staat geschreven.

HAns Labohm Rypke ZeilmakerKijk je naar de Nederlandstalige blogosfeer, dan zie je bv. dat Rypke Zeilmaker en Hans Labohm die onjuiste gang van zaken netjes verder vertaald hebben uit het Engels. Zonder zich de moeite te getroosten te verfiëren of hun wilde beschuldigen ook maar ergens op stoelen. Ze leveren m.a.w. kritiek op een paper die ze niet eens gelezen hebben, en dat ze het houden op het overschrijven van onzin op Engelstalige blogs waar de juiste gang van zaken ver te zoeken is.

Met wetenschap heeft dat allemaal weinig te maken.

De eerste pseudoskeptische blog waarin wordt aangehaald dat de temperatuurreconstructies duidelijk aantonen dat de aarde afgelopen 150 jaar snel opwarmde moet ik overigens nog tegenkomen. Dat gegeven zou immers de ongefundeerde kritiek op Marcott et al. doen verdampen. Terwijl pseudoskeptici uiteraard net krampachtig trachten de realiteit te ontkennen dat de aarde opwarmt. Feiten zijn daarbij enkel maar een hinderlijke bijkomstigheid.

Dit blijkt ook uit de reacties onder de blogposts van Zeilmaker en Labohm: logischerwijze zou je kunnen verwachten dat deze auteurs hierom stevig bekritiseerd zouden worden omwille van hun onjuiste weergave van de paper. Het tegendeel is waar.

Climategate.nl heeft een systeem met duimpjes waarin een ‘waardering’ kan gegeven worden, en wat commentor Christo overkwam toen hij/zij de juiste gang van zaken weergaf zie je hieronder:
Rypke Zeilmaker

Uiteraard is er niet één vaste commentor die het een lor kan schelen dat Rypke Zeilmaker een paper aanvalt die hij niet eens gelezen heeft. Dat hebben ze zelf immers ook niet, en dat interesseert hun ook niet. Dat blog, net als het blog van Labohm, gaat immers niet om wetenschap, maar om het verwrongen wereldbeeld van de deelnemers, die overal complotten ontwaren.