By Dr. Sebastian Lüning and Prof: Fritz Vahrenholt
[Translated, edited by P Gosselin]
Five years ago Greenpeace painted climate doom and gloom on the wall. Supposedly ocean acidification was posing a threat to the phytoplankton and thuswas a danger to the food supply for all sea life. In addition to its importance for nourishing sea life, the tiny algae are also one of the most important producers of oxygen. Estimates peg its contribution to the oxygen content of our atmosphere somewhere between 50 and 80 percent. Moreover they absorb huge amounts of carbon dioxide.
In July 2010 Sibylle Zollinger of the Greenpeace website warned:
Climate change: ocean acidification damaging plankton.
For a second time, this summer Greenpeace traveled to the Arctic together with independent scientists. In one of the biggest European experiments, researchers from 12 nations investigated the consequences of ocean acidification over the past 6 weeks. Their conclusion: rising greenhouse gas emissions are having an unexpected powerful impact on plankton. […] At the so-called Mesokosmen – the world’s largest test tube – various degrees of ocean acidification were simulated. Greenpeace ship Esperanza will be bringing it back to Kiel this week. How is sea life in the Arctic coping with the lower pH value? What has been changing in the ecosystem? These were the questions that the largest collection of data concerning ocean acidification is seeking to answer. The results will evaluated and interpreted over the coming weeks. The first results, however, already show huge impacts: The phytoplankton, for example the diatom, is reproducing more slowly when the ocean is acidic Because these plankton are at the very bottom of the food chain, this may have massive consequences for the entire food supply and for the ecosystem.”
It is a good thing that scientists are looking into this. But what is not so good is that Greenpeace already announced “results” from the scientific expedition before any data had been evaluated and interpreted. This is an unscientific approach. Naturally there is a desire to produce big headlines, especially when the expensive Greenpeace ship was made available to the scientists. But that does not mean that proper scientific procedure can be thrown overboard and the title of a press release can claim a result that is not even at hand.
This is especially dubious because since then robust results have become available, and they happen to point to the opposite picture of what Greenpeace hastily claimed. On July 10, 2015, the University of Edinburgh announced the research results in a press release: the phytoplankton have a a far better ability to adapt to rising CO2 concentrations than what was previously assumed. A team of researchers led by C-Elisa Schaum grew more than 400 generations of the tiny algae under CO2 conditions that are projected to be seen in the year 2100. Here the plankton performed splendidly. The paper appeared in the ISME Journal of the Nature family of journals.
Here’s the press release from the University of Edinburgh:
Algae to cope well in climate change
Marine algae with a key role in supporting life on Earth may be better equipped to deal with climate change than expected, research shows.
Scientists investigated the likely future impact of changing environmental conditions on ocean phytoplankton, a microscopic plant that forms the basis of all the oceans’ food chains. Phytoplankton is important for absorbing carbon dioxide from the atmosphere, while generating much of the oxygen needed to sustain life on Earth. The study grew phytoplankton at the high carbon dioxide levels predicted for the year 2100 and beyond. The algae was allowed to evolve through 400 generations, with some exposed to varying levels of CO2 and some kept at constant CO2 levels.
Researchers found that phytoplankton exposed to fluctuating CO2 levels was better able to cope with further changes in conditions, compared with algae grown in stable CO2 levels. The finding suggests that populations of the algae will adapt more to the varied conditions expected in future than was previously thought based on experiments at stable conditions. Scientists found however that the algae developed in changing CO2 conditions evolved more and were smaller than those grown in stable conditions. These factors may impact on how well marine animals can feed off phytoplankton, and how efficiently the algae is able to take carbon out of the atmosphere and sink to the deep ocean.
Plankton in some regions of the ocean may evolve more than others under global climate change, because some regions of ocean are currently more variable than others. The studies, published in the International Society for Microbial Ecology journal and Proceedings of the Royal Society B, were supported by the Royal Society, the European Commission, and the Scottish Universities Life Sciences Alliance.
Dr Sinead Collins, School of Biological Sciences: “Predicting how populations of ocean algae will respond to changing ocean conditions is difficult, but these results suggest that populations from highly changeable environments are better placed to deal with additional environmental change than previously suspected.”