The Ocean: A Barometer for Mass Extinction

12/31/2011 10:59 EST | Updated 03/01/2012 05:12 EST

Early in December I was sitting in the middle of Milne Bay, off the coast of Papua New Guinea, eating my breakfast. To my left at the table was Charlie Veron, one of the world's most preeminent scientists on extinction. We were on our way to see ocean vents where pure carbon dioxide is leaking from the ocean floor -- a reminder that we are sitting on the edge of a ring of fire, one of the most active volcanic areas of the world.

It is always true that the future is here for us to see. We only have to look for it.

It is a scientific fact that the oceans are acidifying at an alarming rate and the impact of this will be profound. By looking at ocean vents and seeing what happens to the coral around them, we have a crystal ball for the future. The acidity around ocean vents mimics what will happen to all reefs if the current rate of acidification continues. The ocean is where life began and is the canary in the coalmine for mass extinctions.

Charlie's work has shown that the last four mass extinctions on earth were linked to changes that preceded them in the oceans. By examining the history of oceans we know how mass extinctions occurred and how evolution proceeded. Moreover, we can get clues from the past as to how the earth will evolve.

He paints a picture of reefs covered in algae, of molluscs -- which are one-third of all biomass in the poles -- unable to grow their shells, of monoculture coral reefs, and lots of seagrass everywhere. Not to mention a huge proliferation of jellyfish. He says that we are sitting on top of the "headwaters of biodiversity": From here life flows to the Indian Ocean, the Pacific, the North and South. It is from here that life extinct in one part of the world can be regenerated and flow to the rest of the world.

This might all sound like science fiction, but it is actually objective science. Here are the facts: The concentration of carbon dioxide in the atmosphere is higher today than it has been for the last million years. The oceans absorb a large part of the carbon dioxide we generate and most of this occurs in colder water (just think of how the carbon dioxide in your soft drink bubbles off at higher temperatures). This causes ocean acidification and already has resulted in a 30 per cent scientifically measured increase since the start of the Industrial Revolution.

Back at the breakfast table, Katharina Fabricius, a world expert on ocean acidification who was sitting to my right, showed us how CO2 bubbling through coral actually eats away at the skeleton of entire reefs. We filled a bunch of bottles covering the breakfast table with samples taken from the area around these vents. There are also tiles, which will be left here to collect coral growth and compare it to reefs close by where there is no carbon bubbling out of the earth.

Up until now, scientists have been bringing samples to their labs and testing their responses to CO2. Today, the organisms will be tested in their own habitat. The indigenous elders say that they remember the vents bubbling when they were young children, so we know that coral in this area has been exposed to CO2 for at least 70 years. This provides researchers with a way of testing their hypotheses over long periods.

Branching coral grows faster than massive coral, but is more sensitive to environmental changes. Very few coral species can handle the growing acidity. There is one species that does, Porites coral, and it will be the winner. We can expect coral monoculture when the oceans get more acidic, as has happened before. And because this species does not provide a good home for other marine life, we will see it disappear. We will also see very healthy seagrass with nothing growing on it, looking like a beautiful golf course in the middle of the ocean.

The moral of the story is there will be winners and losers -- more losers than winners.

Peeking 50 years into the future at our current rate of burning fossil fuels, we see extinction of many species and a few sites in the world where diversity of coral will be preserved. We see a world of vastly reduced biodiversity and man's role in all of this will be uncertain. We are truly gobbling up our children's world at an alarming rate.

These scientists are adamant: Once our atmosphere and oceans are acidified there is no way to reverse it, except over millennia.

We need to do what we can to stop it now.