If the ocean is going to stop doing its thing, why should I keep cutting emissions?” says McKinley. Cite this Article: Photo by Mint Images Limited/Alamy Stock Photo, This volcanic ash reflected sunlight and temporarily lowered global temperatures, researchers predict a similar temporary shrinkage, https://www.hakaimagazine.com/news/the-ocean-carbon-sink-has-set-the-next-political-hurdle/. Calcium-containing materials such as coccolithophore, a microscopic one-celled alga, participate in subtracting carbon from the natural cycle. “At the beginning, we thought the important aspect was the increase in atmospheric CO 2 ,” says Le Quéré. This volcanic ash reflected sunlight and temporarily lowered global temperatures. While these dynamics are undoubtedly key to bear in mind, Goldstein cautions that we are still a long way from having to worry about the ocean releasing the carbon it has trapped through this process. The longer it takes to cut emissions, the longer this equilibration phase will take, simply because there will be more carbon in the ocean to balance out. “A well-designed climate policy should be able to incorporate unexpected results and be able to adapt,” Goldstein says. Like a giant sponge, the ocean and the organisms within it have soaked up the carbon dioxide by dissolving it from the air and through photosynthesis. Consequently, it can be destabilized and re-emit carbon into the atmosphere. Actually, in high latitudes water stores CO2 more easily because low temperatures facilitate atmospheric CO2 dissolution (hence the importance of Polar Regions in the carbon cycle). The research shows that as the concentration of carbon dioxide in the atmosphere falls there comes a point when the ocean will start releasing its stored carbon, flipping from a carbon sink to a carbon source. After all, one can easily see the political traps and arguments that could ensue when the ocean stops swallowing carbon dioxide, and even starts spewing it back. The rate at which the ocean absorbs carbon dioxide depends on how much there is in the atmosphere. Ecosystem restoration remains a priority to improve storage of carbon excessively released into the atmosphere and requires ambitious policies. For instance, chalk cliffs are an accumulation of coccolithophores (micro algae covered with plating made of limestone) on the ocean seabed, which have later resurfaced to the continent due to geological movement. The reason for this is simple: when it comes to carbon dioxide content, the ocean and the atmosphere seek equilibrium. These processes form the well-known « ocean carbon pump ». Combined with the fact that the ocean had already sucked up more carbon following the Mount Pinatubo eruption, this lessened the difference between the amount of carbon dioxide in the atmosphere and in the ocean. Once the machine is activated, it will be difficult to stop it. However, the concept of carbon sink is very controversial. There are myriad unanswered questions about how much of our carbon the ocean will continue to take up—and for how long—but answering them has been a central focus of climate research. Miriam Goldstein, a biological oceanographer and the director of ocean policy at the Center for American Progress, agrees that solid science, and investment in scientific research, is key to good climate policy. This uncertainty should encourage us to be more careful and to preserve marine ecosystems. “You can imagine people who will say, Well, these cuts in emissions are hard. Cooling the ocean, even by a smidge, increases the water’s ability to dissolve carbon dioxide—so it absorbed more. It is composed of two compartments: a biological pump* which transfers surface carbon towards the seabed via the food web (it is stored there in the long term), and the physical pump* which results from ocean circulation.