Peter Hannam, Environmental Editor of the Sydney Morning Herald writes
Just when you thought you had most of the threats from climate change covered.
We are looking on now as warming oceans stress the world's coral reefs, prompting them to turn white, including our Great Barrier Reef.
We also know that our oceans have become about 30 per cent more acidic since pre -industrial times as they absorb the billions of tonnes of carbon dioxide released from our burning of fossil fuels and forrests, making it harder for shellfish and crabs to form shells.
But now, some of the first evidence is emerging of what scientists have been expecting for decades: oxygen levels in some oceans are beginning to fall and widespread evidence of the trend should be evident from 2030 onwards.
Warming seas absorb less oxygen at the surface. Another effect of a changing climate is that oceans turn over less, so that oxygen at the surface has less chance of moving deeper.
So it goes on. Meanwhile there is nothing to see here really. We have an election going on.