Oceans are getting more acid

In the global debate about carbon emissions and global warming, it's often assumed that if the link between emissions and warming can be disproved then we are free to emit as much carbon dioxide as we like.

Not so. A clear and undeniable link exists between carbon emissions and ocean acidification - the process that lowers the pH of the world's oceans as they absorb more carbon dioxide from the atmosphere. This has devastating effects for marine ecosystems and, by implication, our ability to feed ourselves.