I’d very much like to see a report that is not basically conjecture. A report that experimentally links small changes in ocean pH to massive global plankton decline is the one I want to see. My engine of conjecture probably makes as many RPMs as the next man’s, and probably more than most. The following excerpt from a NOAA report on acidification is representative of sort of thing I see: “Low pH may be a factor in the current oyster reproductive failure; however, more research is needed to disentangle potential acidification effects from other risk factors, such as episodic freshwater inflow, pathogen increases, or low dissolved oxygen. It is premature to conclude that acidification is responsible for the recent oyster failures, but acidification is a potential factor in the current crisis to this $100 million a year industry, prompting new collaborations and accelerated research on ocean acidification and potential biological impacts.”

See: http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F

Notice the report doesn’t mention the facts that atmospheric CO2 and ocean pH is the same along the Texas and Louisiana Gulf Coasts where the unpolluted oyster harvesters are doing just fine. It’s all self-serving conjecture. Only empirical experiments with controls can settle the questions. NOAA is saying, “This possibility could be important; give us more money and we will study it some more.” But I suspect no matter how much money we give to NOAA it will never provide answers that would satisfy a numerate critical mind, and which reduce the need for further study.

Acidification, fertilizer runoff, algal blooms and die offs are contributing to a decline in phytoplankton populations. I will look through my research notes to see if I can find you some source journal references if you like.

Best I can understand, the anthropic CO2 component of the atmosphere accounts for most of the increase over the last century. But it’s not nearly as simple as burning fossil fuel causing global warming. The oceans are playing a major role. A couple of years back “Nature” published an alarming article asserting that a recent Secchi disk study of the world’s oceans shows that phytoplankton has declined some 40% over the last century, and continues to decline at about 1% per year. That’s staggering. The basic principle of the Secchi disk lowered on a rope is standard optical measurement of surface water turbidity. The more phytoplankton, the more turbid the water.

Surface waters are generally defined as the waters penetrated and influenced by solar radiation. Should be obvious that clearer waters allow the suns rays to penetrate deeper than they would in turbid waters. But guess what, it takes longer for infrared radiation and conduction to transport heat out of deep water than from shallow water. The huge decline of phytoplankton means the solar energy absorbed by surface waters penetrates deeper and takes longer to radiate out from the surface at night. Phytoplankton has historically provided “shade” for deeper water, and its loss is responsible for some significant portion of rising ocean surface temperatures. The warmer surface waters can hold less CO2 in solution, and the smaller amount of phytoplankton is removing less CO2 through photosynthesis. A significant, but not well quantified, percentage of carbon incorporated into phytoplankton structure eventually winds up permanently sequestered in the abysmal depths. That process is now sequestering 40% less carbon than it did a century ago.

What we urgently need to discover now is what is causing the phytoplankton decline. The naïve answer is that the warmer temperatures and higher CO2 levels are causing the phytoplankton decline, but all the physics I can understand is suggesting the exact opposite. The phytoplankton decline is causing the warmer temperatures and higher CO2 levels. Since the Nature article was first published, I have seen no report of anything plausible that might account for the decline. The scale of the plankton decline dwarfs the burning of fossil fuels. I haven’t seen any treatment of oceanic heat fluxes as they relate to phytoplankton populations either. I’m a lot more concerned about the ocean’s tiny phytoplankton than I am about great white sharks. I’m guessing it will prove impossible to stabilize atmospheric carbon and global climate without first stabilizing and restoring the phytoplankton population.

Hi Stephen, I edited your reply and hope I did it justice.