The ocean pH will drop to 7.8. It was 8.2 in 1800; at the beginning of the 21st century, it is 8.1. A decline of just 0.1 point, using the logarithmic scale, means a 30% increase in acidity. By 2100, the oceans will be 150% more acidic than before the Industrial Revolution. This will likely cause the collapse of marine life and the extinction of a large portion of current living species. The Sixth Mass Extinction, which will cause the extinction of 24% of living species (minimum 9%, maximum 32%) within a century. The extinction rate could be even higher over several centuries, but it will still not reach rates comparable to the other 5 mass extinctions (which reached up to 96% of living species), but it will still be higher than other smaller mass extinctions (such as those of 185 million years ago and 55 million years ago).
