{"id":148939,"date":"2018-05-10T13:57:46","date_gmt":"2018-05-10T12:57:46","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/universo\/?p=148939"},"modified":"2018-05-10T13:57:46","modified_gmt":"2018-05-10T12:57:46","slug":"la-temperatura-del-suelo-y-el-cambio-climatico","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2018\/05\/10\/148939","title":{"rendered":"La temperatura del suelo y el cambio clim\u00e1tico"},"content":{"rendered":"

\"perfil-del-suelo-temperatura\"<\/p>\n

Perfiles de la temperatura del suelo a diferentes escalas y foto extra\u00edda de la nota de prensa original<\/span>.<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <\/span><\/p>\n

Cuando se habla de <\/span>la temperatura del suelo<\/span><\/span><\/strong>, nos solemos referir a la que puede medirse en su superficie, y esta fluct\u00faa <\/span>en estrecha reacci\u00f3n con la del aire<\/span><\/span><\/strong>. <\/span>\u00a0<\/span>Ahora bien, <\/span>las estimaciones son muy distintas de las que se miden a lo largo del perfil ed\u00e1fico<\/span><\/span><\/strong>. La Taxonom\u00eda americana clasifica los suelos hasta dos metros de profundidad, mientras que la WRB tan solo a uno. En cualquier caso el perfil mentado puede prolongarse mucho m\u00e1s en diversos edafotaxa. Debe tambi\u00e9n tenerse en cuenta que <\/span>diferentes tipos de suelos se encuentran constituidos por materiales que poseen diferentes propiedades a la hora de difundir el calor<\/strong><\/span>. Hace ya decenios, mientras hac\u00eda el servicio militar, estuve colaborando con el lamentablemente fallecido <\/span>Aureliano Blanco de Pablos<\/span><\/a> del CEBAS (ahora conocido por el IRNASA) del CSIC en Salamanca. Aureliano era microclimat\u00f3logo y realizamos varias experiencias de campo juntos acerca de la <\/span>temperatura y humedad del suelo a diferentes profundidades<\/span><\/span><\/strong>. Una de las primeras lecciones que aprend\u00ed, es que, por lo general, <\/span>la temperatura desciende r\u00e1pidamente conforme avanzamos desde la superficie hacia la base del solum, siendo las fluctuaciones d\u00eda\/noche \u00a0e incluso las estacionales, escasas conforme penetramos desde arriba hacia abajo, por el consabido amortiguamiento de los materiales ed\u00e1ficos<\/strong><\/span>. De aqu\u00ed mi experiencia para poder discutir la sorprendente nota de prensa de la que hablamos hoy. <\/span>\u00a0<\/span><\/p>\n

\u00a0<\/span>En la Universidad de Berkeley, algunos \u201cexpertos\u201d parecen haberse preocupado por <\/span>el olvido en los estudios de cambio clim\u00e1tico a la hora de medir la temperatura del perfil ed\u00e1fico hasta varios metros de profundidad<\/strong>, y estimar sus<\/span> repercusiones sobre la p\u00e9rdida de carbono, v\u00eda respiraci\u00f3n del suelo<\/strong><\/span>. Por lo tanto, sus indagaciones hubieran estado m\u00e1s que justificadas, si no hubiera sido porque de suelos deb\u00edan saber muy poco mientras que\u00a0de sus microclimas, nada en absoluto, si se lee la nota de prensa. Utilizaron un instrumental muy sofisticado y durante m\u00e1s de un a\u00f1o. <\/span>Los resultados obtenidos eran llamativamente alarmantes: estimaron una gran p\u00e9rdida de carbono al<\/strong><\/span> aumentar artificialmente la temperatura, por lo que: \u00a1c\u00f3mo no!, la nota de prensa advierte al \u201cmundo, mundial\u201d, de los efectos devastadores que se producir\u00edan de aumentar tres o cuatro grados la temperatura de la atm\u00f3sfera, como predicen algunos modelos clim\u00e1ticos (muchas mayores emisiones de CO2 que las previstas hasta la fecha). <\/span>\u00a0<\/span>\u00a0<\/span>Y una vez m\u00e1s: \u00a1c\u00f3mo no!, clamaron que esta grave omisi\u00f3n, repercute seriamente en las estimas y predicciones de los modelos clim\u00e1ticos. <\/span>Eso s\u00ed por su ignorancia en todo lo relacionado con la <\/strong>microclimatolog\u00eda del suelo, calentaron el perfil del suelo por igual (homog\u00e9neamente), desde la superficie hasta m\u00e1s de dos metros. \u00bfUn error sin importancia?. \u00a1Pues va a ser que no!. Se trata de una barbaridad injustificable. \u00a0Reitero que si calentamos el aire tres o cuatro grados, la elevaci\u00f3n de la temperatura a uno o dos metros ser\u00e1 much\u00edsimo menor, no llegando en casi ning\u00fan caso a sobrepasar unas d\u00e9cimas de grado<\/strong><\/span>. En consecuencia <\/span>todos sus alarmistas c\u00e1lculos se vienen abajo<\/span><\/span><\/strong>. Estudiar los efectos de los cambios clim\u00e1ticos sobre un recurso natural demanda trabajar conjuntamente con expertos en el tema. Empero al parecer a los primeros \u00bfexpertos? Les parece irrelevante. Y as\u00ed una gran idea se convierte en un deplorable estudio falazmente alarmante. No me dedico <\/span>\u00a0<\/span>a buscar notas de prensa y menos a\u00fan a leer papers con vistas a criticar a los expertos que trabajan sobre cambio clim\u00e1tico, os lo puedo asegurar. Simplemente me leo las noticias de los boletines a los que estoy inscrito y\u2026.. por cada una de ellas razonable, se publican varias que son para tirarse de los pelos. Y hablamos de la Universidad de Berkeley. \u00a1Pero qu\u00e9 pena!, cu\u00e1nto dinero y esfuerzo malgastado por no leer algo, unos principios b\u00e1sicos, antes de comenzar la investigaci\u00f3n.\u00a0<\/span>\u00a0<\/span>\u00a0<\/span><\/p>\n

Juan Jos\u00e9 Ib\u00e1\u00f1ez\u00a0\u00a0<\/strong><\/span><\/p>\n

Os dejo con la noticia en Suajili, ya que para que voy a traducir tanta tonter\u00eda\u2026\u2026<\/em><\/span><\/p>\n

\u00a0<\/span><\/p>\n

Soils could release much more carbon than expected as climate warms<\/span><\/a>
\n<\/strong>by Staff Writers; Berkeley CA (SPX) Mar 13, 2017<\/p>\n

Soils could release much more CO2 than expected into the atmosphere as the climate warms<\/strong>, according to new research by scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).<\/strong><\/p>\n

Their findings are based on a field experiment that<\/strong>, for the first time, explored what happens to organic carbon trapped in soil when all soil layers are warmed, which in this case extend to a depth of 100 centimeters<\/strong>. The scientists discovered that warming both the surface and deeper soil layers at three experimental plots increased the plots’ annual release of CO2 by 34 to 37 percent over non-warmed soil<\/strong>. Much of the CO2 originated from deeper layers, indicating that deeper stores of carbon are more sensitive to warming than previously thought<\/span><\/strong>.<\/p>\n

The results shed light on what is potentially a big source of uncertainty in climate projections. Soil organic carbon harbors three times as much carbon as Earth’s atmosphere. In addition, warming is expected to increase the rate at which microbes break down soil organic carbon, releasing more CO2<\/strong> into the atmosphere and contributing to climate change.<\/p>\n

But, until now, the majority of field-based soil warming experiments only focused on the top five to 20 centimeters of soil<\/span><\/strong> – which leaves a lot of carbon unaccounted for. Experts estimate soils below 20 centimeters in depth contain more than 50 percent of the planet’s stock of soil organic carbon. The big questions have been: to what extent do the deeper soil layers respond to warming?<\/span> <\/strong>And what does this mean for the release of CO2 into the atmosphere?<\/p>\n

\u00abWe found the response is quite significant<\/strong>,\u00bb says Caitlin Hicks Pries, a postdoctoral researcher in Berkeley Lab’s Climate and Ecosystem Sciences Division. She conducted the research with co-corresponding author Margaret Torn, and Christina Castahna and Rachel Porras, who are also Berkeley Lab scientists.<\/p>\n

\u00abIf our findings are applied to soils around the globe that are similar to what we studied, meaning soils that are not frozen or saturated, our calculations suggest that by 2100 the warming of deeper soil layers could cause a release of carbon to the atmosphere at a rate that is significantly higher than today, perhaps even as high as 30 percent of today’s human-caused annual carbon emissions<\/strong> depending on the assumptions on which the estimate is based,\u00bb adds Hicks Pries.<\/p>\n

The need to better understand the response of all soil depths to warming is underscored by projections that, over the next century, deeper soils will warm at roughly the same rate as surface soils and the air<\/span><\/strong>.<\/p>\n

In addition, Intergovernmental Panel on Climate Change simulations of global average soil temperature, using a \u00abbusiness-as-usual\u00bb scenario<\/strong> in which carbon emissions rise in the decades ahead, predict that soil will warm 4 degrees Celsius by 2100.<\/p>\n

To study the potential impacts of this scenario, the Berkeley Lab scientists pioneered an innovative experimental setup at the University of California’s Blodgett Forest Research Station, which is located in the foothills of California’s Sierra Nevada mountains<\/strong>. The soil at the research station is representative of temperate forest soils, that in turn account for about 13.5 percent of soil area worldwide<\/strong>.<\/p>\n

The scientists built their experiment around six soil plots that measure three meters in diameter<\/span><\/strong>.<\/span> The perimeter of each plot was ringed with 22 heating cables that were vertically sunk more than two meters underground. They warmed three of the plots 4 degrees Celsius for more than two years, leaving the other three plots unheated to serve as controls<\/span><\/strong>.<\/p>\n

They monitored soil respiration three different ways over the course of the experiment<\/span><\/strong>. Each plot had an automated chamber that measured the flux of carbon at the surface every half hour. In addition, one day each month, Hicks Pries and the team measured surface carbon fluxes at seven different locations at each plot.<\/p>\n

A third method probed the all-important underground realm<\/strong>. A set of stainless steel \u00abstraws\u00bb was installed below the surface at each plot. The scientists used the straws to measure CO2 concentrations once a month at five depths between 15 and 90 centimeters. By knowing these CO2 concentrations and other soil properties, they could model the extent to which each depth contributed to the amount of CO2 released at the surface.<\/p>\n

They discovered that, of the 34 to 37 percent increase in CO2 released at the three warmed plots, 40 percent of this increase was due to CO2 that came from below 15 centimeters<\/span><\/strong>.<\/strong> They also found the sensitivity of soil to warming was similar across the five depths<\/span><\/strong>.<\/p>\n

The scientists say these findings suggest the degree to which soil organic carbon influences climate change may be currently underestimated<\/strong>.<\/p>\n

\u00abThere’s an assumption that carbon in the subsoil is more stable and not as responsive to warming as in the topsoil, but we’ve learned that’s not the case<\/strong>,\u00bb says Torn. \u00abDeeper soil layers contain a lot of carbon, and our work indicates it’s a key missing component in our understanding of the potential feedback of soils to the planet’s climate<\/strong>.\u00bb<\/p>\n","protected":false},"excerpt":{"rendered":"

Perfiles de la temperatura del suelo a diferentes escalas y foto extra\u00edda de la nota de prensa original.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Cuando se habla de la temperatura del suelo, nos solemos referir a la que puede medirse en su superficie, y esta fluct\u00faa en estrecha reacci\u00f3n con la del aire. \u00a0Ahora bien, las estimaciones son muy distintas de las que se miden a lo largo del perfil ed\u00e1fico. La Taxonom\u00eda americana clasifica los suelos hasta dos metros de profundidad, mientras que la WRB tan solo a uno. En cualquier caso el perfil mentado puede prolongarse mucho m\u00e1s en diversos edafotaxa. Debe tambi\u00e9n tenerse\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[596,608,590,618,589,587,595],"tags":[46647,47994,46702,47993],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/148939"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=148939"}],"version-history":[{"count":10,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/148939\/revisions"}],"predecessor-version":[{"id":149594,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/148939\/revisions\/149594"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=148939"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=148939"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=148939"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}