Wednesday, April 16, 2014

Review paper finds effects of ocean "acidification" on corals overblown

A new paper from SPPI and CO2 Science reviews the scientific literature on the response of corals to ocean "acidification" and finds such concerns overblown, and in many cases coral calcification and photosynthetic rates of their symbiotic algae improve with elevated CO2 levels. 

[Illustrations, footnotes and references available in PDF version]
It has been predicted that rates of coral calcification, as well as the photosynthetic rates of their symbiotic algae, will dramatically decline in response to what is typically referred to as an acidification of the world's oceans, as the atmosphere's CO2 concentration continues to rise in the years, decades, and centuries to come. As ever more pertinent evidence accumulates, however, the true story appears to be just the opposite. This summary examines such evidence obtained from field-based studies conducted in the natural ocean.


  1. IPCC agrees, once you dig into the fine print of AR5 reports.

    WGII Report, Chapter 6 covers Ocean Systems. There we find some objective and blunt statements by scientists:

    "Few field observations conducted in the last decade demonstrate biotic responses attributable to anthropogenic ocean acidification" pg 4

    "Due to contradictory observations there is currently uncertainty about the future trends of major upwelling systems and how their drivers (enhanced productivity, acidification, and hypoxia) will shape ecosystem characteristics (low confidence)." Pg 5

    "Both acclimatization and adaptation will shift sensitivity thresholds but the capacity and limits of species to acclimatize or adapt remain largely unknown" Pg 23

    "Production, growth, and recruitment of most but not all non-calcifying
    seaweeds also increased at CO2 levels from 700 to 900 µatm Pg 25

    "Contributions of anthropogenic ocean acidification to climate-induced alterations in the field have rarely been established and are limited to observations in individual species" Pg. 27

    "To date, very few ecosystem-level changes in the field have been attributed to anthropogenic or local ocean acidification." Pg 39

    I am finding much more credible the Senate Testimony of John T. Everett, in which he said:

    "There is no reliable observational evidence of negative trends that can be traced definitively to lowered pH of the water. . . Papers that herald findings that show negative impacts need to be dismissed if they used acids rather than CO2 to reduce alkalinity, if they simulated CO2 values beyond triple those of today, while not reporting results at concentrations of half, present, double and triple, or as pointed out in several studies, they did not investigate adaptations over many generations."

    "In the oceans, major climate warming and cooling and pH (ocean pH about 8.1) changes are a fact of life, whether it is over a few years as in an El Niño, over decades as in the Pacific Decadal Oscillation or the North Atlantic Oscillation, or over a few hours as a burst of upwelling (pH about 7.59-7.8) appears or a storm brings acidic rainwater (pH about 4-6) into an estuary."

    Ron C.

  2. Funny how the IPCC often hides the truth in the fine print, not in the summary for policymakers. Thanks for that summary.


  4. I looked at the oceanic CO2 data contained in the NOAA Ocean Database and found that indeed the ocean's CO2 conc is going up as one would expect from equilibrium partial pressure considerations. However, I did not find a correlation between the annual rate of fossil fuel emissions and annual changes in ocean CO2. For details please see: