{"id":563,"date":"2008-05-08T13:55:30","date_gmt":"2008-05-08T18:55:30","guid":{"rendered":"http:\/\/www.realclimate.org\/index.php\/archives\/2008\/05\/global-cooling-wanna-bet\/langswitch_lang\/sp"},"modified":"2010-11-14T10:51:31","modified_gmt":"2010-11-14T15:51:31","slug":"global-cooling-wanna-bet","status":"publish","type":"post","link":"https:\/\/www.realclimate.org\/index.php\/archives\/2008\/05\/global-cooling-wanna-bet\/","title":{"rendered":"Global Cooling-Wanna Bet? Enfriamiento Global, \u00bfQuieres apostar?<\/lang_sp>Raffreddamento Globale – scommettiamo?<\/lang_it>"},"content":{"rendered":"
\n

By Stefan Rahmstorf, Michael Mann, Ray Bradley, William Connolley, David Archer, and Caspar Ammann<\/small>
\nPor Stefan Rahmstorf, Michael Mann, Ray Bradley, William Connolley, David Archer y Caspar Ammann (Traducido por Angela Carosio)<\/small><\/lang_sp><\/p>\n

Dieser Beitrag erscheint zeitgleich auf deutsch auf KlimaLounge<\/a><\/lang_de>
\nUna traduzione in italiano \u00e8 disponibile qui<\/a><\/lang_it><\/p>\n

Global cooling appears to be the \u201cflavour of the month\u201d. First, a rather misguided media discussion erupted on whether global warming had stopped, based on the observed temperatures of the past 8 years or so (see our post<\/a>). Now, an entirely new discussion is capturing the imagination, based on a group of scientists from Germany predicting a pause in global warming last week in the journal Nature<\/em> (Keenlyside et al. 2008<\/a>).<\/p>\n

Specifically, they make two forecasts for global temperature, as discussed in the last paragraphs of their paper and shown in their Figure 4 (see below). The first forecast concerns the time interval 2000-2010, while the second concerns the interval 2005-2015 (*). For these two 10-year averages, the authors make the following prediction: <\/p>\n

\u201c… the initialised prediction indicates a slight cooling relative to 1994-2004 conditions\u201d<\/p><\/blockquote>\n

Their graph shows this: temperatures in the two forecast intervals (green points shown at 2005 and 2010) are almost the same and are both lower than observed in 1994-2004 (the end of the red line in their graph).<\/p>\n

\"Fig.Keenlyside et al ’08” align = “left” width=90%\/>
\nFigure 4 from Keenlyside et al<\/em> ’08<\/b><\/p>\n

The authors also make regional predictions, but naturally it was this global prediction that captivated most newspaper stories around the world (e.g. New York Times<\/a>, BBC News<\/a>, Reuters, Bloomberg and so on), because of its seeming contradiction with global warming. The authors emphasise this aspect in their own media release, which was titled: Will Global Warming Take a Short Break?<\/a><\/p>\n

That this cooling would just be a temporary blip and would change nothing about global warming goes without saying and has been amply discussed elsewhere (e.g. here<\/a>). But another question has been rarely discussed: will this forecast turn out to be correct?<\/p>\n

We think not \u2013 and we are prepared to bet serious money on this. We have double-checked with the authors: they say they really mean this as a serious forecast, not just as a methodological experiment. If the authors of the paper really believe that their forecast has a greater than 50% chance of being correct, then they should accept our offer of a bet; it should be easy money for them. If they do not accept our bet, then we must question how much faith they really have in their own forecast.<\/p>\n

The bet we propose is very simple and concerns the specific global prediction in their Nature<\/em> article. If the average temperature 2000-2010 (their first forecast) really turns out to be lower or equal to the average temperature 1994-2004 (*), we will pay them \u20ac 2500. If it turns out to be warmer, they pay us \u20ac 2500. This bet will be decided by the end of 2010. We offer the same for their second forecast: If 2005-2015 (*) turns out to be colder or equal compared to 1994-2004 (*), we will pay them \u20ac 2500 \u2013 if it turns out to be warmer, they pay us the same. The basis for the temperature comparison will be the HadCRUT3 global mean surface temperature<\/a> data set used by the authors in their paper.<\/p>\n

To be fair, the bet needs an escape clause in case a big volcano erupts or a big meteorite hits the Earth and causes cooling below the 1994-2004 level. In this eventuality, the forecast of Keenlyside et al. could not be verified any more, and the bet is off.<\/p>\n

The bet would also need a neutral arbiter \u2013 we propose, for example, the director of the Hadley Centre, home of the data used by Keenlyside et al., or a committee of neutral colleagues. This neutral arbiter would also decide whether a volcano or meteorite impact event is large enough as to make the bet obsolete.<\/p>\n

We will discuss the scientific reasons for our assessment here another time \u2013 first we want to hear from Keenlyside et al. whether they accept our bet. Our friendly challenge is out \u2013 we hope they will accept it in good sportsmanship.<\/p>\n

(*) We adopt here the definition of the 10-year intervals as in their paper, which is from 1 November of the first year to 31 October of the last year. I.e.: 2000-2010 means 1 November 2000 until 31 October 2010.<\/p>\n

Update<\/strong>: We have now published part 2 of this bet<\/a> with our scientific arguments. <\/p>\n

_______________________
\nUpdate<\/b>: Andy Revkin has weighed in<\/a> at “dot earth”.
\n<\/small>
\nUpdate 5\/11\/08<\/b>: so has Anna Barnett<\/a> at Nature’s<\/em> ‘climate feedback’ blog
\n<\/small><\/p>\n

<\/p>\n

El enfriamiento global parece ser el sabor del mes. Primero, ha brotado una discusi\u00f3n descarriada en los medios de comunicaci\u00f3n sobre si el calentamiento global se ha detenido, bas\u00e1ndose en las temperaturas observadas en los pasados 8 a\u00f1os (ver nuestro correo aqu\u00ed<\/a>). Ahora hay una nueva discusi\u00f3n que est\u00e1 capturando la imaginaci\u00f3n, basada en un grupo de cient\u00edficos alemanes que predijeron una pausa en el calentamiento global la semana pasada en un art\u00edculo en la revista Nature (Keenlyside et al. 2008<\/a>).<\/p>\n

En dicho art\u00edculo se hacen dos pron\u00f3sticos de temperaturas globales, y se discuten en los \u00faltimos p\u00e1rrafos y se muestran en la Figura 4 (ver abajo). El primer pron\u00f3stico se refiere a los a\u00f1os 2000-2010, mientras que el segundo se refiere a los a\u00f1os 2005-2015 (*). Los autores hacen las siguientes predicciones para estos dos intervalos promedio de diez a\u00f1os:<\/p>\n

\u201cla predicci\u00f3n inicial indica un leve enfriamiento con respecto a las condiciones en los a\u00f1os 1994-2004\u201d<\/p><\/blockquote>\n

El gr\u00e1fico muestra lo siguiente: Las temperaturas en los dos intervalos pronosticados (los puntos verdes muestran 2005 y 2010) son casi iguales y son ambas m\u00e1s bajas que las observadas en 1994-2004, correspondiente al final de la l\u00ednea roja en el gr\u00e1fico.<\/p>\n

\"Fig.Keenlyside et al ’08” align = “left” width=90%\/>
\nFigura 4 extra\u00edda del art\u00edculo de Keenlyside et al, 2008<\/b><\/p>\n

Los autores tambi\u00e9n hacen pron\u00f3sticos regionales, pero fue, naturalmente, el pron\u00f3stico global el que cautiv\u00f3 la mayor\u00eda de las historias en diarios alrededor del mundo (ej.: BBC Noticias http:\/\/www.nytimes.com\/2008\/05\/01\/science\/earth\/01climate.html?_r=1&>New%20York%20Times,%20\u00bfEl Calentamiento Global, se Tomar\u00e1 unas Cortas Vacaciones? <\/a> <\/p>\n

No es siquiera necesario explicar que este enfriamiento es solo un peque\u00f1o parpadeo y que no cambiar\u00e1 nada del calentamiento global. El tema ha sido ampliamente discutido en otros sitios (ej. aqu\u00ed<\/a>). Pero hay una pregunta que se ha discutido poco: \u00bfSer\u00e1 correcto el pron\u00f3stico?<\/p>\n

Nosotros pensamos que no, y estamos dispuestos a apostar una importante suma de dinero por nuestra postura. Hemos verificado dos veces con los autores: ellos insisten en que su art\u00edculo es un pron\u00f3stico serio y que no se trata de un experimento metodol\u00f3gico. Si los autores realmente piensan que su pron\u00f3stico tiene una chance de ser correcta mayor al 50%, entonces deber\u00edan aceptar nuestra apuesta; ser\u00eda una oportunidad de ganar dinero f\u00e1cil. Si no aceptan nuestra apuesta, deber\u00edamos cuestionar, entonces, cuanta fe realmente tienen en su pron\u00f3stico.<\/p>\n

La apuesta que proponemos es muy simple y concierne su pron\u00f3stico espec\u00edfico en el art\u00edculo de la revista Nature. Si la temperatura promedio de 2000-2010 (su primer pron\u00f3stico) resulta ser m\u00e1s baja o igual que la temperatura promedio de 1994-2004 (*), les pagaremos \u20ac 2500. Si resulta ser m\u00e1s alta, ellos nos pagan \u20ac 2500 a nosotros. Esta apuesta ser\u00e1 decidida a fines del 2010. Ofrecemos lo mismo para el segundo pron\u00f3stico: si la temperatura promedio de 2005-2015(*) resulta ser m\u00e1s baja o igual comparando con la temperatura promedio de 1994-2004(*) les pagaremos \u20ac 2500, si resulta ser m\u00e1s alta, ellos nos pagan a nosotros esa cifra. Tomaremos el HADCRUT3, conjunto de datos del promedio de la temperatura de superficie global, como base para comparar las temperaturas, que es la misma base de datos utilizada por los autores en el art\u00edculo.<\/p>\n

Para ser justos, necesitar\u00edamos una cl\u00e1usula de salvaguardia, por si un gran volc\u00e1n hace erupci\u00f3n o si un gran meteorito golpea la tierra y causa un enfriamiento menor al del promedio de 1994-2004. En este caso, el pron\u00f3stico de Keenlyside et al. no se podr\u00eda verificar y por lo tanto la apuesta ser\u00eda inv\u00e1lida.<\/p>\n

La apuesta tambi\u00e9n tendr\u00eda que tener un \u00e1rbitro neutral, proponemos, por ejemplo, el director del Hadley Centre, donde se albergan los datos utilizados por Keenlyside et al., o un comit\u00e9 de colegas neutrales. Dicho \u00e1rbitro neutral tambi\u00e9n decidir\u00e1 si una eventual explosi\u00f3n volc\u00e1nica o un impacto de meteorito son lo suficientemente grandes para invalidar la apuesta.<\/p>\n

Discutiremos pronto las razones cient\u00edficas de nuestra evaluaci\u00f3n, primero queremos ver si Keenlyside et al. acepta nuestra apuesta. Nuestro amigable desaf\u00edo ha sido propuesto y esperamos que sea aceptado con buen esp\u00edritu deportivo.<\/p>\n

(*) Adoptamos aqu\u00ed la misma definici\u00f3n de intervalos de 10 a\u00f1os que en su art\u00edculo, que va del 1 de noviembre del primer a\u00f1o al 31 de octubre del \u00faltimo a\u00f1o, ej.:2000-2010 significa 1 de noviembre de 2000 hasta 31 de octubre de 2010.<\/small><\/p>\n

Actualizaci\u00f3n:<\/strong> Ya hemos publicado la segunda parte<\/a> de esta apuesta con nuestros argumentos cient\u00edficos.
\n<\/lang_sp><\/p>\n\n<\/div> ","protected":false},"excerpt":{"rendered":"

By Stefan Rahmstorf, Michael Mann, Ray Bradley, William Connolley, David Archer, and Caspar Ammann Por Stefan Rahmstorf, Michael Mann, Ray Bradley, William Connolley, David Archer y Caspar Ammann (Traducido por Angela Carosio) Dieser Beitrag erscheint zeitgleich auf deutsch auf KlimaLounge Una traduzione in italiano \u00e8 disponibile qui Global cooling appears to be the \u201cflavour of […]<\/p>\n","protected":false},"author":10,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[5,1],"tags":[],"class_list":{"0":"post-563","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-climate-modelling","7":"category-climate-science","8":"entry"},"aioseo_notices":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/563","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/comments?post=563"}],"version-history":[{"count":1,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/563\/revisions"}],"predecessor-version":[{"id":5360,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/563\/revisions\/5360"}],"wp:attachment":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/media?parent=563"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/categories?post=563"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/tags?post=563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}