"As we considered the cumulative effect of what humankind does to the oceans, the implications became far worse than we had individually realised.
"We've sat in one forum and spoken to each other about what we're seeing, and we've ended up with a picture showing that almost right across the board we're seeing changes that are happening faster than we'd thought, or in ways that we didn't expect to see for hundreds of years."
These "accelerated" changes include melting of the Greenland and Antarctic ice sheets, sea level rise, and release of methane trapped in the sea bed.
"What we're seeing at the moment is unprecedented in the fossil record - the environmental changes are much more rapid," Professor Rogers told BBC News.
"We've still got most of the world's biodiversity, but the actual rate of extinction is much higher [than in past events] - and what we face is certainly a globally significant extinction event."
This is really bad news which adds to all the other really bad news we've been seeing on the environment generally. While we're dicking around putting in a solar panel here, and a windmill there, we are continuing to deforest, acidify the seas, melt the ice caps and generally fucking up the environment. All the time it seems most people are absolutely blind to this reality, and the abuse being meted out to environmentalists is unprecedented.