By burning fossil fuels we are responsible for the increase of carbon dioxide in the Earth's atmosphere. Aside from raising temperatures globally, this is also affecting our oceans. The massive production of CO2 is causing ocean acidification, and the results are frightening.
Researches on this matter are quite recent and very difficult to get into, especially because it is impossible to study acidification in isolation; the results may vary depending on the amount of sunlight, temperature and the presence of oxygen. Nevertheless it has been proven that the impact on marine faune is devastating, especially for the formation of shells and coral reefs.
This growing acidity is killing the marine ecosystem, although researchers in China may have found a way to off-set these effects. They showed that seaweed can represent a valid solution because of its ability to intake CO2. Seaweeds are extremely fast-growing and if produced in big quantities it can take in carbon dioxide, through photosynthesis, which is then removed from water as it is harvested.
Seaweed farms are already a big thing in Asia, but mostly for edible purposes. But this marine crop has many other uses beyond food. It can be used to produce fuels and medicines, not considering the shelter they would provide to those fishes that are under constant threat from augmenting acidification.
Only by covering 9% of the ocean surface with seaweed crops we could be able to entirely replace fossil fuels for the production of renewable and sustainable energy.
As Tim Flannery writes in his book Atmosphere of hope - Searching for solutions to the climate crisis: "One study asserted that seaweed farming could produce enough biomethane to replace all of today's needs in fossil fuel energy, while removing 53 gigatonnes of CO2 per year directly from biogas production [...] A side benefit would be an increase in sustainable fish production, providing 200 kilograms per capita per year of fish for a population of 10 billion".