Changing ocean chemistry : an introduction to this special issue

Abstract

The modern industrialized and urbanized world, dubbed the "Anthropocene" by Paul Crutzen (2006), includes the past 250 years of multiple human impacts. Nobel Prize winner and atmospheric chemist Crutzen states:

During the past 3 centuries human population increased tenfold to 6,000 million, growing by a factor of four during the past century alone. More than half of all accessible fresh water is used by mankind. Fisheries remove more than 25% of the primary production of the oceans in the upwelling regions and 35% in the temperature continental shelf regions. 30–50% of the world's land surface has been transformed by human action. Coastal wetlands have lost 50% of the world's mangroves. More nitrogen is now fixed synthetically and applied as fertilizers in agriculture than fixed naturally in all terrestrial ecosystems. Many of the world's rivers have been dammed or diverted.