Ocean fertilisation as a climate change mitigation measure was first proposed in the 1980s. The idea is this: phytoplankton—the equivalent of land plants in the sea, the base of the food chain—can remove CO2 from the atmosphere through photosynthesis, but in many marine areas they don’t grow because of nutrient limitation. The solution: add nutrients to the sea to boost the phytoplankton, leading to more marine life and less CO2. But more than 30 years later, this geoengineering approach to climate change has not gained much traction, and remains controversial because of its possible direct and indirect effects.
In this TEACHING UNIT we offer you the opportunity to analyse whether ocean fertilisation is a valid potential future strategy against climate change or more of a dead end.