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Algae that live in and under the sea ice play a much greater role for the Arctic food web than previously assumed. In a new study, biologists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) showed that not only animals that live directly under the ice thrive on carbon produced by so-called ice algae. Even species that mostly live at greater depth depend to a large extent on carbon from these algae. This also means that the decline of the Arctic sea ice may have far-reaching consequences for the entire food web of the Arctic Ocean. Their results have been published online now in the journal Limnology & Oceanography.

The summer sea ice in the Arctic is diminishing at a rapid pace and with it the habitat of ice algae. The consequences of this decline for the Arctic ecosystem are difficult to predict. Scientists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research showed the significance of ice algae for the Arctic food web in this context. "A number of studies have already speculated that ice algae are an important energy source for the polar ecosystems. We have now been able to show that not only animals associated with ice meet the majority of their carbon needs from ice algae, but that, surprisingly, so do species that mostly live at greater depths," says lead author Doreen Kohlbach.

Destacados científicos advierten: la contaminación del fósforo es una preocupación importante. Tenemos que acelerar los tratamientos de recuperación de los lagos, o aceptar la mala calidad del agua dulce. En una serie de estudios publicados en un número especial de la revista Water Research, los principales científicos evalúan cómo controlar la contaminación por fósforo en los lagos.

The way clouds cover the Earth may be changing because of global warming, according to a study published Monday that used satellite data to track cloud patterns across about two decades, starting in the 1980s.

Clouds in the mid-latitudes shifted toward the poles during that period, as the subtropical dry zones expanded and the highest cloud-tops got higher.

These changes are predicted by most climate models of global warming, even though those models disagree on a lot of other things related to clouds, says Joel Norris, a climate scientist at the University of California, San Diego.

Combinando los datos del clima y la mortalidad, los investigadores han estimado que 315 muertes en Londres y 735 muertes en el centro de París pueden ser fuertemente vinculados a la ola de calor en 2003, con temperaturas récord en toda Europa. Tomando un paso más allá su análisis, se determina que 64 (± 3) muertes por el conjunto de datos de Londres y 506 (± 51) muertes por el conjunto de datos de París son atribuibles al cambio climático antropogénico

An MIT analysis of how best to reduce fine particulate matter in the atmosphere has brought some surprising results. Due to past regulations, levels of key emissions that form those harmful particles are now lower than they were a decade ago, causing some experts to suggest that cutting them further might have little effect. Not true, concludes the MIT study. Using an atmospheric model, the researchers found that new policies to restrict the same emissions would be even more effective now than they were in the past. Further analysis elucidated the chemical processes — some unexpected — that explain their findings. Their results demonstrate the importance of tailoring air pollution policies to specific situations and of addressing a variety of emissions in a coordinated way.