Put the acid on Great Barrier Reef doomsayers

There is nothing more symbolic of the natural beauty of Australia than the Great Barrier Reef.

This makes it a powerful emotional tool to strike fear into the hearts of citizens. The "ocean acidification" hypothesis, that corals and shellfish will die due to higher levels of carbon dioxide dissolved in the sea, is often used to stoke those fears.

Here's why I don't believe there is a shred of evidence to support these claims.

When the slight global warming that occurred between 1970 and 2000 came to a virtual standstill, the doomsayers adopted ­"climate change", which apparently means all extreme weather events are caused by human emissions of CO2.

Cold, hot, wet, dry, wind, snow and large hailstones are attributed to humanity's profligate use of fossil fuels. But the pause in global warming kept on and became embarrassing around 2005.

Something dire was needed to prop up the climate disruption narrative. "Ocean acidification" was invented to provide yet another apocalyptic scenario, only this one required no warming or severe weather, just more CO2 in the atmosphere.

The story goes that as CO2 ­increases in the atmosphere the oceans will absorb more of it and this will cause them to become acidic - well, not exactly, but at least to become less basic. This in turn is predicted to dissolve the coral reefs and kill the oysters, clams, mussels and algae that have calcareous shells. It was named "global warming's evil twin".

Seawater in the open ocean is typically at a pH of 8.0-8.5 on a scale of 0-14, where 0 is the most acidic, 14 is most basic and 7 is neutral. Ocean acidification from increased CO2 is predicted to make the ocean less basic, perhaps to pH 7.5 under so-called worst-case projections.

How do I know that increased CO2 will not kill the coral reefs and shellfish? Let me count the ways.

First, contrary to popular ­belief, at 400 parts per million (0.04 per cent), CO2 is lower now in the atmosphere than it has been during most of the 550 million years since modern life forms emerged during the Cambrian period. CO2 was about 10 times higher then than it is today.

Corals and shellfish evolved early and have obviously managed to survive through eras of much higher CO2 than present levels. This alone should negate the "predictions" of species extinction from CO2 levels nowhere near the historical maximum.

Second, due to its high concentration of basic elements such as calcium and magnesium, sea­water has a powerful buffering capacity to prevent large swings in pH due to the addition of CO2.This self-correcting capacity of seawater will ensure the pH will remain well within levels conducive to calcification, the process whereby shells and coral structures are formed. Marine shells are largely made of calcium carbonate, the carbon of which is derived from the CO2 dissolved in the seawater.