Have ever thought of the effects of oceans’ pH level on the environment? The rising level of acidity in the oceans and other water bodies will worsen the condition of global warming, scientists have said.
According to the scientists, a link between the world’s oceans’ pH and climate change, that has remained unnoticed until now, could dramatically speed up global warming by lowering production of a smelly molecule important for cloud formation. This means that humanity’s CO2 emissions could warm the Earth by an additional 0.5°C by 2100.
Carbon dioxide soaked up by seawater will cause plankton to release less cloud-forming compounds back into atmosphere, according to the study conducted by Katharina Six and her group of the Max Planck Institute for Meteorology, Germany. As the oceans absorbs excess CO2 produced by humans, they are becoming more acidic, which affects the biology of marine ecosystems.
Acidification would lead certain marine organisms to emit less of the sulphur compounds that help to seed the formation of clouds and so keep the planet cool.
Atmospheric sulphur, which mainly comes from the sea, is a check against global warming. Phytoplankton — photosynthetic microbes that drift in sunlit water — produces a compound called dimethylsulphide (DMS). Some of this enters the atmosphere and reacts to make sulphuric acid, which clumps into aerosols, or microscopic airborne particles. Aerosols seed the formation of clouds, which help cool the Earth by reflecting sunlight.
Six says that the factors affecting dimethyl sulfide production are very complex. The trend of lower pH leading to lower dimethyl sulfide production is real but ‘how strong it is is an open question’, she adds. ‘We definitely need more datasets, especially from the subtropics and tropical areas. On the other hand the datasets we have [in the polar and temperate regions] are in the areas where we expect the biggest change in pH, as the polar oceans are absorbing most of the CO2.’
All agree that it is important to recognize that marine organisms will be affected by environmental changes and that this may impact the climate in return. “CO2 that is absorbed by the ocean is still climate-relevant”, says Six.