Al igual que las hojas de los maples de Nueva Inglaterra, el fitoplancton, las microalgas en la base de la mayor parte de las cadenas alimenticias oceánicas, realizan la fotosíntesis cuando se exponen a la luz solar. En el proceso, absorben dióxido de carbono de la atmósfera, convirtiéndolo a hidratos de carbono y oxígeno. Muchas especies de fitoplancton también liberan sulfuro de dimetilo (DMS) a la atmósfera, donde forma aerosoles de sulfato, que pueden reflejar la luz del sol directamente o aumentar la cobertura de nubes y la reflectividad, lo que resulta en un efecto de enfriamiento. La capacidad del fitoplancton para eliminar el dióxido de carbono (CO2) de la atmósfera y producir aerosoles que promueven el enfriamiento adicional ha hecho de la fertilización de los océanos, mediante la dispersión masiva de sulfito de hierro y otros nutrientes que estimulan el crecimiento del fitoplancton, un método de geoingeniería atractiva para reducir el calentamiento mundial.
articles
Diet drinks may not "save" you calories
Want fries with that diet soda? You aren’t alone, and you may not be “saving” as many calories as you think by consuming diet drinks. A new study that examined the dietary habits of more than 22,000 U.S. adults found that diet-beverage consumers may compensate for the absence of calories in their drinks by noshing on extra food that is loaded with sugar, sodium, fat and cholesterol.
Lunar crust found to be highly fractured
Scientists believe that about 4 billion years ago, during a period called the Late Heavy Bombardment, the moon took a severe beating, as an army of asteroids pelted its surface, carving out craters and opening deep fissures in its crust. Such sustained impacts increased the moon’s porosity, opening up a network of large seams beneath the lunar surface.
Now scientists at MIT and elsewhere have identified regions on the far side of the moon, called the lunar highlands, that may have been so heavily bombarded — particularly by small asteroids — that the impacts completely shattered the upper crust, leaving these regions essentially as fractured and porous as they could be. The scientists found that further impacts to these highly porous regions may have then had the opposite effect, sealing up cracks and decreasing porosity.
Air Quality in Scotland continuing to improve
A new report published today shows Scottish emissions of most air pollutants have continued to fall, with significant reductions in emissions of all air pollutants since 1990.
The announcement of the official figures was welcomed by Environment Minister Aileen McLeod who said an updated action plan to tackle nitrogen dioxide would soon be published.
Dr McLeod said: “Air pollution is harmful to human health and can contribute to climate change, and I very much welcome the significant progress that has been made reducing emissions of nitrogen oxides and other air pollutants in Scotland.
Oceanic Phytoplankton contribute to ice formation in clouds
Researchers from the Arctic Research Programme, managed at British Antarctic Survey, have shown for the first time that phytoplankton (plant life) in remote ocean regions can contribute to rare airborne particles that trigger ice formation in clouds.
Results published today in the journal Nature show that the organic waste from life in the oceans, which is ejected into the atmosphere along with sea spray from breaking waves, stimulates cloud droplets to freeze into ice particles. This affects how clouds behave and influence global climate, which is important for improved projections of future climate change.
Why we're wired for laziness
Those of you who spend hours at the gym with the aim of burning as many calories as possible may be disappointed to learn that all the while your nervous system is subconsciously working against you. Researchers reporting in the Cell Press journal Current Biology on September 10 have found that our nervous systems are remarkably adept in changing the way we move so as to expend the least amount of energy possible. In other words, humans are wired for laziness.