How does rising atmospheric CO2 affect marine organisms?

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Mr. President, it's NOT "Carbon Pollution," it's the "Elixir of Life!"
Volume 16, Number 26: 26 June 2013

On June 25th, President Obama unveiled his plan to reduce what he refers to as "carbon pollution" -- the emission of gaseous carbon dioxide into the air that primarily results from the burning of fossil fuels. In discussing the rationale for his plan, the President claims that carbon dioxide, or CO2, "causes climate change and threatens public health" and that "cutting carbon pollution will help keep our air and water clean and protect our kids." Unfortunately, President Obama's statements could not be further from the truth. Far from being a "pollutant," carbon dioxide is the Elixir of Life.

Nearly a quarter of a century ago, my father and two of his co-workers grew some water lilies in sunken metal stock tanks located out-of-doors and enclosed within clear-plastic-wall open-top chambers through which air of either 350 or 650 ppm CO2 was continuously circulated (Idso et al. 1990). Over the course of the next two growing seasons, he and his colleagues measured a number of plant responses to these two environmental treatments, the former of which we will call "normal" and the latter of which -- according to the classification scheme of President Obama -- we will call "polluted."

What my father and his associates learned from their experiment was truly amazing. Although the dictionary defines a pollutant as "a harmful chemical or waste material discharged into the water or atmosphere" - and in my father's experiment, the offending substance went into both of these environmental reservoirs - the water lilies in the CO2-polluted enclosures seemed to grow better than the water lilies in the normal enclosures, right from the very start of the study.

Although the first new growth from the original rhizomes that were planted in the layers of soil at the bottoms of the tanks all reached the surface of the water at essentially the same time, the leaves that unfurled themselves in the CO2-polluted tanks were slightly larger than those in the normal tanks. The percent dry matter contents of the leaves in the CO2-polluted tanks were also greater. And these two factors combined to produce leaves in the CO2-polluted tanks that were composed of 68% more dry matter, on average, than leaves produced in the non-polluted tanks.

In addition to being larger and more substantial, the leaves in the CO2-polluted tanks had more company: there were 75% more of them than there were in the normal tanks over the course of the initial five-month growing season (which, incidentally, lasted two weeks longer in the CO2-polluted tanks). Each of the plants in the CO2-polluted tanks also produced twice as many flowers as the plants growing in normal air; and the flowers that blossomed in the CO2-polluted air were more substantial than those that bloomed in the air of normal CO2 concentration. They had more petals, the petals were longer, they had a greater percent dry matter content, and each flower consequently weighed about 50% more. In addition, the stems that supported the flowers were slightly longer in the CO2-polluted tanks; and the percent dry matter contents of both the flower and leaf stems were greater, so that the total dry matter in the flower and leaf stems in the CO2-polluted tanks exceeded that of the flower and leaf stems in the non-polluted tanks by approximately 60%.

Table 1. Mean values of various characteristics of water lilies grown out-of-doors at Phoenix, AZ, over the period 18 August 1987-18 January 1988 at 350 and 650 ppm CO2. Adapted from Idso et al. (1990).

Just above the surface of the soil that covered the bottoms of the tanks, there were also noticeable differences. Plants in the CO2-polluted tanks had more and bigger basal rosette leaves, which were attached to longer stems of greater percent dry matter content, which led to the total biomass of these portions of the plants being 2.9 times greater than the total biomass of the corresponding portions of the plants in the unpolluted tanks. In addition, plants in the CO2-polluted tanks had more than twice as many unopened basal rosette leaves.

The greatest differences of all were hidden within the soil that covered the bottoms of the stock tanks. When half of the plants were harvested at the conclusion of the first growing season, the number of new rhizomes produced over that period was discovered to be 2.4 times greater in the CO2-polluted tanks than it was in the unpolluted tanks; while the number of major roots produced there was found to be 3.2 times greater than the number produced in the normal environment. And as with all other plant parts, the percent dry matter contents of the new roots and rhizomes were also greater in the CO2-polluted tanks.

Overall, the total dry matter production within the submerged soils of the water lily ecosystems was 4.3 times greater in the CO2-polluted tanks than it was in the normal tanks; while the total dry matter production of all plant parts - those in the submerged soil, those in the free water, and those in the air above - was 3.7 times greater in the high-CO2 enclosures.

Over the second growing season, the growth enhancement in the CO2-polluted tanks was somewhat less; but the plants in the CO2-polluted environments were so far ahead of the plants in the normal water lily ecosystems that, in their first five months of growth, they produced what it took the plants in the normal air fully 21 months to produce.

If only all air and water pollutants were as bad as CO2, what a wonderful world it would be. As Shakespeare so obviously and correctly stated before the United States of America and its Environmental Protection Agency were ever dreamt of, "a rose by any other name would smell as sweet." Clearly, government edicts may change the classification of a substance, but they cannot change its nature!

Two years ago, I collaborated with my father in the production of a long-awaited work, a book we entitled "The Many Benefits of Atmospheric CO2 Enrichment: How humanity and the rest of the biosphere will prosper from this amazing trace gas that so many have wrongfully characterized as a dangerous air pollutant!" Using hundreds of references from the peer-reviewed scientific literature, we demonstrated the undeniable fact that, far from being a pollutant, atmospheric carbon dioxide is, in fact, the elixir of life. It is the primary raw material out of which plants construct their tissues, which in turn are the materials out of which animals construct theirs. This knowledge is so well established, in fact (or so we thought!), that we humans - and all the rest of the biosphere - are described in the most basic of terms as carbon-based lifeforms. Nowadays, however, it seems that all we ever hear about atmospheric CO2 are the presumed negative consequences of its increasing concentration.

Time and again, world governments, non-governmental organizations, international agencies, societal think tanks, and even respectable scientific organizations attempting to assess the potential consequences of this phenomenon, have spent multiple millions of dollars writing and promoting large reports about it. Yet, nearly all of these endeavors have failed miserably, by not properly evaluating, or even acknowledging, the manifold real and measurable benefits of the ongoing rise in the air's CO2 content. As a result, the many important and positive impacts of atmospheric CO2 enrichment remain underappreciated and largely ignored in the debate over what to do, or not do, about anthropogenic CO2 emissions.

President Obama's war on CO2 is simply the latest example of such ignorance. It's time to wake up and treat CO2 not as a pollutant, but as it truly is -- the elixir of life!

Craig Idso

Idso, S.B., Allen, S.G. and Kimball, B.A. 1990. Growth response of water lily to atmospheric CO2 enrichment. Aquatic Botany 37: 87-92.