Shipping contributes to ocean acidification

The potential effect on surface water pH of emissions of SO X and NO X from global ship routes is assessed. The results indicate that regional pH reductions of the same order of magnitude as the CO 2 ‐driven acidification can occur in heavily trafficked waters. These findings have important consequences for ocean chemistry, since the sulfuric and nitric acids formed are strong acids in contrast to the weak carbonic acid formed by dissolution of CO 2 . Our results also provide background for discussion of expanded controls to mitigate acidification due to these shipping emissions.