With the economy melting down, it’s been easy to forget about other looming catastrophes. Here's one: Up to 50 percent of the fuels emitted over the past 200 years have been absorbed by the world's oceans, and emissions since the Industrial Revolution have increased the acidity of the sea by about 30 percent. According to British scientist Carol Turley this spike in acidity could lead to a "mass extinction" among underwater wildlife, which would threaten humans' food supply. While some take issue with Turley's claim, saying that overfishing will affect sea animals before Ph levels do, a bay off the coast of Naples, Italy supports her prophecy. The Bay of Naples has been over-acidified thanks to volcanic CO2 vents, and many sea creatures are in short supply. Turley will be chairing a session on ocean acidification at the Copenhagen Climate Change Congress.