# The effect of CO2 concentration on the pH of the ocean

I'm confused about how increased $$\ce{CO2}$$ concentration in the atmosphere affects the pH of the ocean.

The increase in $$\ce{CO2}$$ concentration means the pH of the ocean will decrease (by several chemical reactions). However, as there is more $$\ce{CO2}$$ in the atmosphere, ocean temperatures will rise meaning the ocean will absorb less $$\ce{CO2}$$, likely slowing down ocean acidification.

In short, the rise in $$\ce{CO2}$$ seems to have two contrasting effects on the pH of the ocean. Am I interpreting this correctly? If so, how is ocean acidification a problem?

For reference, the article I read is Barker and Ridgwell (2012), Ocean Acidification, Nature Education Knowledge.

• I'm voting to close this question as off-topic because it is about mechanisms in earth or environmental science rather than biology itself. – David Feb 25 at 8:17
• Best move this to Earth Science stack its a classic environmental science question of global economic processes. – aliential Feb 25 at 9:02
• CO2 acidifies sea water. I had a saltwater tank ( 75 gal) with a large amount of green plants ( calurpa). Water parameters were correct for sea water ( alkalinity , etc). The pH would drop ( 8.2) when the lights were off and rise ( 8.5) when the lights were on and the calurpa was absorbing CO2 and making O2. The numbers are from memory; My log book is not presently handy . I found the pH shift surprising because as ,with all salt tanks, it had substantial water movement facilitating exchange with air. – blacksmith37 Feb 25 at 17:32
• I think this is a reasonable question ... the answer, I believe (see below), hangs on an understanding of the solubility of CO2 in the oceans and the fact that they are not currently saturated. This is a really important issue in climate research. – M Juckes Feb 25 at 18:36
• Being aware of the rate of the processes would help you. There are essentially thousands of processes having opposite effect in any complex system. – y chung Feb 26 at 23:32