 So when we think about carbon uptake by the ocean, in the context of anthropogenic climate change, we've put a lot of CO2 into the atmosphere. About 30 to 40% of that CO2 has been taken up into the surface ocean, and it has a short residence time in the surface ocean, so it can either exchange back with the atmosphere, or some of that carbon can be taken up by the phytoplankton and then transferred to the deeper ocean. Scientists are also thinking about how they might speed up the uptake of carbon in the ocean using the biological carbon pump, and that respect is actually trying to stimulate photosynthesis. In the southern ocean we have an excess of nutrients there for various reasons, but one of the reasons is actually iron is limiting, and so there are proposals to actually fertilize the southern ocean with iron because it's anemic. The idea is that we could stimulate productivity, or stimulate photosynthesis, and it would draw down more carbon, but that comes with consequences. So we need, as scientists, to think very carefully about whether these options are viable, and that we have social license to undertake these sort of experiments, and into the future whether we should be doing it, because it will have consequences for the deeper ocean, which has other organisms in longer residence time, so it will remain there for a longer period of time.