Air-tight argument on carbon dioxide

Oceans make waves in man-made climate change debate

- DAVID A HUGHES

OVER the past 250 years, as we have burned coal, oil and gas, we have generated about two trillion tonnes of carbon dioxide.

Most of this was dumped directly into the atmosphere, which contains a total of some 3.5 trillion tonnes. Yet measurements of carbon isotopes in the atmosphere show that less than 700 billion tonnes (< 20%) is man-made. Therefore at least 1.3 trillion tonnes of all the carbon dioxide we have produced has disappeared from the atmosphere.

CO2 emissions have increased but still only amount to 0.6% of the oceans’ capacity to absorb gas

Let's investigate the possible ways in which this huge amount of carbon dioxide could have found its way out of the atmosphere.

The atmosphere is bound above by space, where only the very lightest gases, such as hydrogen and helium, are being lost at a significant rate. The loss of heavier gases such as carbon dioxide is exceedingly slow, so we can rule out that it might have escaped into space.

The lower boundary includes rocky parts of the earth's crust, living objects and bodies of water. All of these interact with carbon dioxide and with one another, depending upon the physical conditions, such as light levels, temperature, pressure and humidity.