Last updated on November 21st, 2015
Fizzy Oceans Spell Doom
As an almost instananeous follow up (the interconnectedness of all things?) to my recent disappointment about the launch failure of the OCO satellite, the BBC, Guardian, Telegraph etc have all been reporting some recent climate work from Plymouth.
An Italian Bay
There’s now so much CO2 being absorbed by the oceans that their pH is being significantly lowered. A sea bay off Italy is giving us, in a microcosm, a glimpse of real possible future conditions in the Earth’s oceans if the current accelerating rate of carbon dioxide climate forcing is continued.
The bay is volcanically located and CO2 bubbles up through the sea floor. In all other respects, it’s a normal bit of the Mediterranean. So it’s got a standard mix of fish, molluscs and vegetation, and the standard mix of predator-prey species.
Identified many years ago by Sir John Murray, the CCD is the ocean depth where dissolving calcium carbonate (like sea shells) matches the rate that calcium carbonate of either type (organic or non-organic) is deposited. In the remote past it was very shallow and produced the huge beds of limestone and chalk like the white cliffs of Dover. Or the Alps! (the beds in the old Tethys Sea are over 30km thick!)
Now its quite a way down (over 4km!)
However, in the Italian bay, there’s so much CO2 that the sea is so acidic that it makes the CCD effectively zero! The plants grow as a monoculture of sea grass on the abundant CO2. The shell creatures (like limpets) can’t make their shells fast enough and they have no real protection. Of course, for sea birds and similar predators, it’s a short term food bonanza. But what happens when all the limpets are gobbled up and gone? And what if you are a creature that can’t eat sea grass?
This, in a nutshell, is the problem we face with our whole world. What will we eat when things don’t grow very well any more? What will we do when we’ve gobbled up all our fossil fuels?