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Bushfires and extreme heat in south-east Australia Ash Wednesday, Black Friday, 7ter Februar 2009Los incendios forestales y el calor extremo en el sureste de Australia

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Guest commentary by David Karoly, Professor of Meteorology at the University of Melbourne in Australia

On Saturday 7 February 2009, Australia experienced its worst natural disaster in more than 100 years, when catastrophic bushfires killed more than 200 people and destroyed more than 1800 homes in Victoria, Australia. These fires occurred on a day of unprecedented high temperatures in south-east Australia, part of a heat wave that started 10 days earlier, and a record dry spell.

This has been written from Melbourne, Australia, exactly one week after the fires, just enough time to pause and reflect on this tragedy and the extraordinary weather that led to it. First, I want to express my sincere sympathy to all who have lost family members or friends and all who have suffered through this disaster.

There has been very high global media coverage of this natural disaster and, of course, speculation on the possible role of climate change in these fires. So, did climate change cause these fires? The simple answer is “No!” Climate change did not start the fires. Unfortunately, it appears that one or more of the fires may have been lit by arsonists, others may have started by accident and some may have been started by fallen power lines, lightning or other natural causes.

Maybe there is a different way to phrase that question: In what way, if any, is climate change likely to have affected these bush fires?

Dieser Beitrag erscheint zeitgleich auf deutsch auf PrimaKlima.
Una traducción en español está disponible aquí.
Una traduzione in italiano è disponibile qui
[Read more…] about Bushfires and extreme heat in south-east Australia Ash Wednesday, Black Friday, 7ter Februar 2009Los incendios forestales y el calor extremo en el sureste de Australia

On replication

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This week has been dominated by questions of replication and of what standards are required to serve the interests of transparency and/or science (not necessarily the same thing). Possibly a recent example of replication would be helpful in showing up some of the real (as opposed to manufactured) issues that arise. The paper I’ll discuss is one of mine, but in keeping with our usual stricture against too much pro-domo writing, I won’t discuss the substance of the paper (though of course readers are welcome to read it themselves). Instead, I’ll focus on the two separate replication efforts I undertook in order to do the analysis. The paper in question is Schmidt (2009, IJoC), and it revisits two papers published in recent years purporting to show that economic activity is contaminating the surface temperature records – specifically de Laat and Maurellis (2006) and McKitrick and Michaels (2007).

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Antarctic warming is robust

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The difference between a single calculation and a solid paper in the technical literature is vast. A good paper examines a question from multiple angles and find ways to assess the robustness of its conclusions to all sorts of possible sources of error — in input data, in assumptions, and even occasionally in programming. If a conclusion is robust over as much of this as can be tested (and the good peer reviewers generally insist that this be shown), then the paper is likely to last the test of time. Although science proceeds by making use of the work that others have done before, it is not based on the assumption that everything that went before is correct. It is precisely because that there is always the possibility of errors that so much is based on ‘balance of evidence’ arguments’ that are mutually reinforcing.
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Irreversible Does Not Mean Unstoppable Peruuttamaton, ei pysäyttämätönIrreversibile non significa inarrestabileIrreversible no significa imparable

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Susan Solomon, ozone hole luminary and chair of the Nobel Prize winning IPCC, and her colleagues, have just published a paper entitled “Irreversible climate change because of carbon dioxide emissions” in the Proceedings of the National Academy of Sciences. We at realclimate have been getting a lot of calls from journalists about this paper, and some of them seem to have gone all doomsday on us. Dennis Avery and Fred Singer used the word Unstoppable as a battle flag a few years ago, over the argument that the observed warming is natural and therefore there is nothing that humanity can do to alter its course. So in terms of its intended rhetorical association, Unstoppable = Burn Baby Burn. But let’s not confuse Irreversible with Unstoppable. One means no turning back, while the other means no slowing down. They are very different words. Despair not!

Una traduzione in italiano è disponibile qui.
A translation in Finnish is available here
A translation in Chinese is available here.
Una traducción en español está disponible aquí.
[Read more…] about Irreversible Does Not Mean Unstoppable Peruuttamaton, ei pysäyttämätönIrreversibile non significa inarrestabileIrreversible no significa imparable

A global glacier index update Un aggiornamento dell’indice globale dei ghiacciaiActualización del índice glaciar global

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Guest commentary by Mauri Pelto

For global temperature time series we have GISTEMP, NCDC and HadCRUT. Each has worked hard to assimilate global temperature data into reliable and accurate indices of global temperature. The equivalent for alpine glaciers is the World Glacier Monitoring Service’s (WGMS) record of mass balance and terminus behavior. Beginning in 1986, WGMS began to maintain and publish the collection of information on ongoing glacier changes that had begun in 1960 with the Permanent Service on Fluctuations of glaciers. This program in the last 10 years has striven to acquire, publish and verify glacier terminus and mass balance measurement data from alpine glaciers the world over on a timely basis. Spearheaded by Wlfried Haeberli with assistance from Isabelle Roer, Michael Zemp, Martin Hoelzle, at the University of Zurich, their efforts have resulted in the recent publication, “Global Glacier Changes: facts and figures” published jointly with UNEP. This publication summarizes the information collected and submitted by the national correspondents of WGMS portraying the global response of glaciers to climate change, as well as the regional response.

Una traduzione in italiano è disponibile qui.
Una traducción en español está disponible aquí.
[Read more…] about A global glacier index update Un aggiornamento dell’indice globale dei ghiacciaiActualización del índice glaciar global

Warm reception to Antarctic warming story Cálida recepción a la historia del calentamiento de la Antártida

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What determines how much coverage a climate study gets?

It probably goes without saying that it isn’t strongly related to the quality of the actual science, nor to the clarity of the writing. Appearing in one of the top journals does help (Nature, Science, PNAS and occasionally GRL), though that in itself is no guarantee. Instead, it most often depends on the ‘news’ value of the bottom line. Journalists and editors like stories that surprise, that give something ‘new’ to the subject and are therefore likely to be interesting enough to readers to make them read past the headline. It particularly helps if a new study runs counter to some generally perceived notion (whether that is rooted in fact or not). In such cases, the ‘news peg’ is clear.

And so it was for the Steig et al “Antarctic warming” study that appeared last week. Mainstream media coverage was widespread and generally did a good job of covering the essentials. The most prevalent peg was the fact that the study appeared to reverse the “Antarctic cooling” meme that has been a staple of disinformation efforts for a while now.

Una traducción en español está disponible aquí.
[Read more…] about Warm reception to Antarctic warming story Cálida recepción a la historia del calentamiento de la Antártida

Sea will rise ‘to levels of last Ice Age’ Il mare raggiungerà “I livelli dell’ultima era glaciale”

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cogee beachThe British tabloid Daily Mirror recently headlined that “Sea will rise ‘to levels of last Ice Age’”. No doubt many of our readers will appreciate just how scary this prospect is: sea level during the last Ice Age was up to 120 meters lower than today. Our favourite swimming beaches – be it Coogee in Sydney or the Darß on the German Baltic coast – would then all be high and dry, and ports like Rotterdam or Tokyo would be far from the sea. Imagine it.

Una traduzione in italiano è disponibile qui.
A chinese translation of this post is available here
[Read more…] about Sea will rise ‘to levels of last Ice Age’ Il mare raggiungerà “I livelli dell’ultima era glaciale”

Reindeer herding, indigenous people and climate change La cría de renos, los indígenas y el cambio climático

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Lavo The Sámi are keenly aware about climate change, and are thus concerned about their future. Hence, the existence of the International Polar Year (IPY) project called EALÁT involving scientists, Sámi from Norway/Sweden/Finland, as well as Nenets from Russia. The indigenous people in the Arctic are closely tuned to the weather and the climate. I was told that the Sámi have about 300 words for snow, each with a very precise meaning.

Una traducción en español está disponible aquí.
[Read more…] about Reindeer herding, indigenous people and climate change La cría de renos, los indígenas y el cambio climático

State of Antarctica: red or blue? Lo stato dell’Antartide: più caldo o più freddo?

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A couple of us (Eric and Mike) are co-authors on a paper coming out in Nature this week (Jan. 22, 09). We have already seen misleading interpretations of our results in the popular press and the blogosphere, and so we thought we would nip such speculation in the bud.

The paper shows that Antarctica has been warming for the last 50 years, and that it has been warming especially in West Antarctica (see the figure). The results are based on a statistical blending of satellite data and temperature data from weather stations. The results don’t depend on the statistics alone. They are backed up by independent data from automatic weather stations, as shown in our paper as well as in updated work by Bromwich, Monaghan and others (see their AGU abstract, here), whose earlier work in JGR was taken as contradicting ours. There is also a paper in press in Climate Dynamics (Goosse et al.) that uses a GCM with data assimilation (and without the satellite data we use) and gets the same result. Furthermore, speculation that our results somehow simply reflect changes in the near-surface inversion is ruled out by completely independent results showing that significant warming in West Antarctica extends well into the troposphere. And finally, our results have already been validated by borehole thermometery — a completely independent method — at at least one site in West Antarctica (Barrett et al. report the same rate of warming as we do, but going back to 1930 rather than 1957; see the paper in press in GRL).

Una traduzione in italiano è disponibile qui.
[Read more…] about State of Antarctica: red or blue? Lo stato dell’Antartide: più caldo o più freddo?

CNN is spun right round, baby, right round

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With the axing of the CNN Science News team, most science stories at CNN are now being given to general assignment reporters who don’t necessarily have the background to know when they are being taken for a ride. On the Lou Dobbs show (an evening news program on cable for those of you not in the US), the last few weeks have brought a series of embarrassing non-stories on ‘global cooling’ based it seems on a few cold snaps this winter, the fact that we are at a solar minimum and a regurgitation of 1970s vintage interpretations of Milankovitch theory (via Pravda of all places!). Combine that with a few hysterical (in both senses) non-scientists as talking heads and you end up with a repeat of the nonsensical ‘Cooling world’ media stories that were misleading in the 1970s and are just as misleading now.

Exhibit A. Last night’s (13 Jan 2009) transcript (annotations in italics).
[Read more…] about CNN is spun right round, baby, right round