As it was predicted in various models and observed in many laboratory tests, so it has been demonstrated in the real world. Mimicking the increase in acidity of the world’s oceans in response to the ever increasing CO2 in the atmosphere, marine scientists from Australia and the US have performed a field experiment in circular reefs along the Great Barrier Reef, in which they increased the pH of the seawater to pre-industrial levels. As a result, the corals in those “pre-industrial” reefs were reported to grow some 7% faster than in seawater with a pH that is normal nowadays.
Mussels can adapt to their acidifying ocean by changing the composition of their hard parts. In an ever more corrosive environment, mussels changed the mineralogical makeup of their calcareous shells. Shells normally consist of calcium carbonate which is ordered in a crystalline fashion, with strong and resistant properties. However, under ocean acidification conditions, with a lower pH, the calcium carbonate of these experimental mussel shells consisted of much more amorphous calcium carbonate, leaving the shells more vulnerable to predation by crabs and seagulls and the crushing forces of waves. This is a very strong example of secondary effects of ocean acidification, where organisms suffer from the consequences of climate change in an almost cryptic way. The danger sits in the fact that these changes on an organism level might go by unnoticed, until it is too late.
From Monday 30 November till Wednesday 11 December, the 21st Convention of Parties of the United Nations Conference on Climate Change –COP21 in short- will take place. A lot of attention has been going to this convention. The main reason for this is the fact that the main goal of this convention is to achieve a legally binding and universal agreement on the climate, with the aim of keeping global warming below a global average of 2 degrees Celsius. A very ambitious, but necessary goal indeed. A grand total of 150 heads of state are expected to arrive on 30 November in Paris, making this an international diplomatic conference of unprecedented magnitude. Should the Convention prove successful, we would be looking at a global-scale effort to not only adapt to climate change and bring down global carbon emissions, but actually re-capture carbon dioxide from the atmosphere and store it on a time scale of millenia.
Already in the IPCC reports of 2014, measures such as afforestation, land use change and carbon capture and storage (CCS) have been put forward as parts of the climate mitigation portfolio. In our opinion, far too little attention is spent on mineral weathering and Enhanced Weathering of Olivine (EWO) in particular. This is in part due to the fact that not much is published about EWO. Large-scale EWO may contribute to atmospheric carbon sequestration, and when applied in coastal sediment management programmes, may prove to be relatively simple to implement. We hope that our research may fill some of the knowledge gaps, so that we can contribute to the climate solution.
Now that the human influence on climate change has been firmly and unequivocally established in the newest IPCC Assessment Reports (ARs) that came out in 2014, the new director of the IPCC, dr. Hoesung Lee, has called for a stronger focus on climate solutions. Among these solutions is Enhanced Weathering of Olivine (EWO), which increases seawater pH, buffer capacity (alkalinity) and the CO2 uptake capacity of seawater. In this way, EWO would address the problem from two sides, mitigating Ocean Acidification and enhancing CO2 uptake.
By now, everyone has heard of global warming, or climate change in one way or another. The International Panel on Climate Change (IPCC) has even established that it is caused by humanity’s continuous emissions of fossil fuel-derived carbon dioxide. Global warming would cause more intense and more frequent stormy weather and of course the rising of the global sea level, by melting the polar ice caps.
Another effect of anthropogenic or “man-made” climate change is Ocean Acidification (OA). Both historical and ongoing carbon dioxide (CO2) emissions flow from our smokestacks to the atmosphere. As the atmosphere constantly balances itself with the world’s oceans, any excess of CO2 in the air will quickly (in a matter of one to two years) end up in the surface seawater. If it would not be for our oceans sucking up a LOT of CO2, we would be in real trouble. However, because the oceans store such enormous amounts of CO2, the seawater is slowly acidifying.
Marine organisms have adapted and evolved over millions of years and are dependent on the chemistry of the seawater being within certain bounds. It is difficult for them to respond to rapid changes in its chemistry, such as is happening nowadays. Mainly organisms that produce calcium carbonate, those being calcareous body parts, are threatened by Ocean Acidification (OA). Shellfish and corals are among the best known that suffer from OA, but there are many other organisms that are under threat in an ocean that turns acidic ever more rapidly.
As our seas are souring up, Global Warming’s Evil Twin is not only threatening all sorts of marine organisms, it also decreases the ocean’s capacity to take up (more) atmospheric CO2, so effectively diminishing our planet’s self-regulating carbon-storage.