Learn how plants respond to higher atmospheric CO2 concentrations

How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Food Security: The Real Planetary Problem
Volume 13, Number 51: 22 December 2010

In a paper recently published in the Journal of Proteome Research, Sarkar et al. (2010) write that "increasing population and unsustainable exploitation of nature and natural resources have made 'food security' a burning issue in the 21st century," echoing sentiments much like those expressed by Farrell (2009), who has noted that "the alarming increase in biofuel production, the projected demand for livestock products, and the estimated food to feed the additional 700 million people who will arrive here by 2016, will have unprecedented consequences," among which are likely to be the unsavory facts that "arable land, the environment, water supply and sustainability of the agricultural system will all be affected," and not in a positive manner. Furthermore, when the human population of the globe reaches 8.7-11.3 billion by the year 2050 (Bengtsson et al., 2006), the situation will become truly intolerable, unless something is done, far in advance of that date, to dramatically mitigate the situation. Thus, as Sarkar et al. suggest, "a normal approach for any nation/region is to strengthen its agricultural production for meeting future demands and provide food security." But a major difficulty, which could well spoil mankind's ability to do so, is the ongoing rise in the atmosphere's ozone concentration, which is the subject of Sarkar et al.'s new paper.

In a study designed to elucidate the many ways in which ozone (O3) is harmful to plants, the eight researchers grew two high-yielding cultivars (Sonalika and HUW 510) of wheat (Triticum aestivum L.) out-of-doors at the Agriculture Research Farm of India's Banaras Hindu University. This was done within open-top chambers that they maintained at the ambient O3 concentration and at elevated O3 concentrations of 25% and 50% above ambient during the peak O3 period of the day (10:00 to 15:00 hours local time) for a total of fifty days, during which period they measured numerous responses of the plants to the two levels of ozone enrichment. So what did they find?

Sarkar et al. determined, among several other things, that the moderate increases in the air's O3 concentration resulted in higher foliar injury, a reduction in photosynthetic efficiency, induced inhibition in photochemical efficacy of photosystem II, lowered concentrations of photosynthetic pigments and proteins, plus what they describe as "drastic reductions" in RuBisCO large and small subunits, while noting that major leaf photosynthetic proteins and important energy metabolism proteins were also "drastically reduced."

In discussing the results of their study, the scientists from India, Japan and Nepal remark that anthropogenic activities have made ozone a "major environmental pollutant of our time," while noting that some are predicting it to be an even "greater problem for the future." And adding this dilemma to the problem of feeding the world over the next few decades and beyond, humanity's future is not looking good. In fact, it's incredibly bleak. So what can be done to help us weather this potentially devastating perfect storm?

Sarkar et al. suggest that we focus on "engineering crops for future high O3," concentrating on maintaining "effective stomatal conductance of plants which can avoid O3 entry but not hamper their productivity." We agree. But not knowing to what extent we will be successful in this endeavor, we need to do something else that we know will work; and that is to allow the air's CO2 content to rise, unimpeded by the misguided efforts of climate alarmists who would curtail anthropogenic CO2 emissions in the guise of fighting what they claim is anthropogenic-induced global warming. This contention is largely theoretical and wholly unproven; but we know that atmospheric CO2 enrichment nearly always acts to increase both the productivity and water use efficiency of nearly all plants, as a result of literally hundreds, if not thousands, of real-world experiments, while it often more than compensates for the negative effects of O3 pollution.

Clearly, we are going to need all of the help we can possibly get to make it unscathed through even the first half of the 21st century; and we cannot afford to throw away any of the means we have at our disposal to help us in this great effort. We have got to see carbon dioxide for what it truly is -- the elixir of life: one of the two raw materials (the other being water) that combine during the process of photosynthesis to produce the substances of plant tissues that provide the food for nearly all human and animal life on the planet, either directly, in the case of herbivores, or indirectly in the case of other life forms. And that makes carbon dioxide just the opposite of what the U.S. Environmental Protection Agency has recently declared it to be -- a dangerous air pollutant. Shame on them! ... and on all those who demonize this life-giving molecule that we expel to the air every time we exhale.

Sherwood, Keith and Craig Idso

Bengtsson, M., Shen, Y. and Oki, T. 2006. A SRES-based gridded global population dataset for 1990-2100. Population & Environment 28: 113-131.

Farrell, D. 2009. Feeding the future. Livestock Research for Rural Development 21: http://www.lrrd.org/lrrd21/12/farr21219.htm

Sarkar, A., Rakwal, R., Agrawal, S.B., Shibato, J., Ogawa, Y., Yoshida, Y., Agrawal, G.K. and Agrawal, M. 2010. Investigating the impact of elevated levels of ozone on tropical wheat using integrated phenotypical, physiological, biochemical, and proteomics approaches. Journal of Proteome Research 9: 4565-4584.