Ocean acidification may cause dramatic changes to phytoplankton
Oceans have absorbed up to 30 percent of human-made carbon dioxide around the world, storing dissolved carbon for hundreds of years. As the uptake of carbon dioxide has increased in the last century, so has the acidity of oceans worldwide. Since pre-industrial times, the pH of the oceans has dropped from an average of 8.2 to 8.1 today. Projections of climate change estimate that by the year 2100, this number will drop further, to around 7.8 — significantly lower than any levels seen in open ocean marine communities today. Now a team of researchers from MIT, the University of Alabama, and elsewhere has found that such increased ocean acidification will dramatically affect global populations of phytoplankton — microorganisms on the ocean surface that make up the base of the marine food chain. In a study published today in the journal Nature Climate Change, the researchers report that increased ocean acidification by 2100...