A Sea Change in a Changing Sea The oceans, seas and coastal areas encompass over 70% of the earth s surface. They are a critical driver of the earth s hydrologic cycle and climate system, important for c- merce, transport, and tourism, a source of economically important living marine resources, minerals such as hydrocarbons, as well as new pharmaceutical compounds. The marine environment provides essential habitats for thousands of marine living 1 2 resources, which in turn contribute significantly to global food security, employment, 3 and trade. Overall, the sea s contribution to human...