Since the industrial revolution began, the ocean has absorbed about a third of the we have produced since then and it is estimated that surface ocean pH has dropped by slightly more than 0.1 units on the logarithmic scale of pH, representing about a 29% increase in . It is expected to drop by a further 0.3 to 0.5 pH units (an additional doubling to tripling of today's post-industrial acid concentrations) by 2100 as the oceans absorb more anthropogenic , the impacts being most severe for coral reefs and the Southern Ocean. These changes are predicted to accelerate as more anthropogenic is released to the atmosphere and taken up by the oceans. The degree of change to ocean chemistry, including ocean pH, will depend on the mitigation and emissions pathways taken by society.