Seven elements that rule the waves

摘要

Even in iron-rich regions of the oceans there is just 30 nanograms of it per kilogram of seawater. It is so critical that it is the main factor limiting life in one-third of the ocean-all living things need iron to survive, and it is essential to photosynthesis. This has led to suggestions that we should fertilise the oceans with iron to promote plankton growth and stem climate change. Since the industrial era, oceans have sucked up roughly 40 per cent of the carbon dioxide we have emitted, and are absorbing more and more each year. Some CO_2 simply dissolves into the water, but the rest is taken up by phytoplankton during photosynthesis.