The Earth’s oceans are taking quite the pounding. As a direct result of people’s activities, most of the accumulated warmth has been absorbed by the oceans. CO2 also presents a problem: chemical reactions involving CO2 work to make the oceans more acidic. It doesn’t take too much of a difference from long-term pH values for life-forms to be negatively impacted. The world’s oceans are currently acidifying at a rate that hasn’t been seen for at least 800,000 years. That acidifying rate is projected to further increase during the remainder of this century.
Something the deniers don’t like to discuss is the observed rate is higher than the agreed-upon results presented in the IPCC reports. Not lower, as would be expected if anthropogenic CO2 emissions weren’t wrecking havoc across the climate system, but higher. Stop to think for one moment what higher CO2 emission rates in this century would mean. Deniers might tell you that plants like CO2; that really, it’s good for the biosphere. Wrong. Higher CO2 concentrations with no change in temperature or rainfall or nitrogen and phosphate would mean weeds would grow much faster than they do today while most other plants would only grow slightly faster. As we know from the science, however, temperatures are projected to increase (by 15-18°F in the central US; up to 27.4°F in the Arctic, for example) and annual rainfall increases in some areas and decreases in others but overall comes in more intense periods – which means droughts are more likely. Changes in nitrogen and phosphate aren’t documented as widely, but for the purposes of discussing this news aren’t critical.
But I’m sure that if ocean pH levels fall enough to cause ecosystems to collapse, the deniers will resort to their usual fallback: “It’s all natural anyway; people can’t possibly have an effect on something as big and complex as the climate; and CO2 isn’t … blah, blah blah.”
The science is pretty clear on most aspects of the expected climatic response to the unbelievable amount of CO2 we’re forcing into the system. It’s getting clearer by the day. Most projections underestimate the timing and magnitude of the effects of doing so; they don’t overestimate them. Too many processes remain under-studied and thus haven’t been included in papers that recommend policy. The oceans’ vitality depends on that changing.