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Hope for the Best, Prepare for the Worst
Volume 14, Number 52: 28 December 2011

As time marches on, and as ever more carbon dioxide accumulates in earth's atmosphere, climate alarmists contend that the planet will experience unprecedented global warming, together with unprecedented increases in all sorts of warming-induced catastrophes, such as floods, droughts, hurricanes, etc. On the other hand, scientists skeptical of climate-alarmist claims contend that the planet will not experience significant CO2-induced global warming, but will instead reap a host of biological benefits provided by the productivity-enhancing and transpiration-reducing effects of atmospheric CO2 enrichment. And this great difference of opinion provides a real challenge for humanity, for no one can know -- with absolute certainty -- what the future will be like; and, as a result, contingency plans must be made, and initial work on them must begin as soon as possible.

For climate alarmists, those plans center around their already-mounted global efforts to curtail -- and ultimately discontinue -- the mining and use of fossil fuels, such as coal, gas and oil, with the stated goal of ultimately reducing anthropogenic CO2 emissions to next-to-nothing, hoping that thereby they can either halt or dramatically curtail the predicted deadly warming and death-dealing consequences that they otherwise foresee occurring. Scientists who are skeptical of this philosophy-turned-policy, however, fear that its implementation could lead to equally dire negative consequences, as several astute researchers have realized that without some extra help from somewhere (such as the growth-promoting, water-conserving consequences of atmospheric CO2 enrichment), mankind will not be able to produce enough food to feed itself before the year 2050 rolls around, without taking all of earth's untapped land and freshwater resources that yet remain for what could be called "wild nature," and thereby consigning the vast majority of the plant and animal species with which we share the planet to the ash heap of history.

So what should be done?

People on both sides of the CO2-climate controversy should realize the need that we have for designing and implementing a contingency plan that both sides of the issue could enthusiastically endorse without the need to abandon their own particular view of the subject; and in an insightful paper in the Journal of Agricultural Science, Shah et al. (2011) describe just such a program, which is currently aimed at the rice plant, but which they indicate could be readily expanded to include other crop plants as well. And the goal of that program is to breed more heat-tolerant and CO2-loving crops.

The seven scientists note, first of all, that "progress in rice breeding has rapidly accelerated due to the availability of the full rice genome sequence (IRGSP, 2005) and intensive quantitative trait loci mapping efforts for a wide range of traits (Ismail et al., 2007)." Therefore, they state that "the availability of high-density genetic and physical maps, expressed sequence tags, genomic sequences and mutant stocks such as T-DNA insertional mutants (Jeon et al., 2000) have established rice as an excellent model plant for the study of heat tolerance among cereals," adding that "the high level of synteny and homology within the Poaceae family will facilitate transfer of identified quantitative trait loci and candidate genes from rice to other cereals (Maestri et al., 2002)." And in this regard, they additionally note that "some cultivars that are not so sensitive to relatively higher temperatures have already been identified," suggesting that when breeding for high-temperature stress, these varieties may be readily used as genetic donors.

With respect to the direct effects of the ongoing rise in the air's CO2 content on crop yields, Shah et al. state that "variation in response of cultivars to CO2 enrichment has already been reported." And in this regard, we note that Ziska et al. (1996) discovered that when seventeen rice cultivars from contrasting ecosystems and origins were exposed to two different CO2 concentrations (373 and 664 ppm), along with two sets of day/night temperatures (29/21 and 37/29°C), rice biomass and yield increases ranged from 10% to 250%, indicative of the great potential for certain rice cultivars to immensely increase their yields in a CO2-enriched and significantly-warmed climate of the future.

And so, we ask again, what should be done?

In light of the several observations and developments discussed above, we suggest that the two sides of the CO2/climate debate continue their separate and divergent analyses of the issue; but let the plant breeders get on with a program of preparing for either the best of times or the worst of times, for whatever earth's future climate turns out to be like, we are going to need a heck of a lot more food than we are currently capable of producing. And we're going to need it just a few short decades from now. Therefore, "because it may take 10-15 years to move from discovery of new advantaged genetics to commercial cultivars of annual grain crops," as the international consortium of Ainsworth et al. (2008) has noted, "developing a robust strategy and supporting the planned work with the best possible facilities should be an urgent priority."

We could not agree more.

Sherwood, Keith and Craig Idso

Ainsworth, E.A., Beier, C., Calfapietra, C., Ceulemans, R., Durand-Tardif, M., Farquhar, G.D., Godbold, D.L., Hendrey, G.R., Hickler, T., Kaduk, J., Karnosky, D.F., Kimball, B.A., Korner, C., Koornneef, M., LaFarge, T., Leakey, A.D.B., Lewin, K.F., Long, S.P., Manderscheid, R., McNeil, D.L., Mies, T.A., Miglietta, F., Morgan, J.A., Nagy, J., Norby, R.J., Norton, R.M., Percy, K.E., Rogers, A., Soussana, J.-F., Stitt, M., Weigel, H.-J. and White, J.W. 2008. Next generation of elevated [CO2] experiments with crops: a critical investment for feeding the future world. Plant, Cell and Environment 31: 1317-1324.

IRGSP (International Rice Genome Sequencing Project). 2005. The map-based sequence of the rice genome. Nature 436: 793-800.

Ismail, A.M., Heuer, S., Thomson, M.J. and Wissuwa, M. 2007. Genetic and genomic approaches to develop rice germplasm for problem soils. Plant Molecular Biology 65: 547-570.

Jeon, J.S., Lee, S., Jung, K.H., Jun, S.H., Jeong, D.H., Lee, J., Kim, C., Jang, S., Yang, K., Nam, J., An, K., Han, M.J., Sung, R.J., Choi, H.S., Yu, J.H., Choi, J.H., Cho, S.Y., Cha, S.S., Kim, S.I. and An, G. 2000. Technical Advance: T-DNA insertional mutagenesis for functional genomics in rice. Plant Journal 22: 561-570.

Maestri, E., Klueva, N., Perrota, C., Gulli, M., Nguyen, H.T. and Marmiroli, N. 2002. Molecular genetics of heat tolerance and heat shock proteins in cereals. Plant Molecular Biology 48: 667-681.

Shah, F., Huang, J., Cui, K., Nie, L., Shah, T., Chen, C. and Wang, K. 2011. Impact of high-temperature stress on rice plant and its traits related to tolerance. Journal of Agricultural Science 149: 545-556.

Ziska, L.H., Manalo, P.A. and Ordonez, R.A. 1996. Intraspecific variation in the response of rice (Oryza sativa L.) to increased CO2 and temperature: growth and yield response of 17 cultivars. Journal of Experimental Botany 47: 1353-1359.