Volume 10, Number 10: 7 March 2007
In a recent Science editorial (Pachauri, 2007), the chairman of the Intergovernmental Panel on Climate Change (IPCC) discusses "the challenge of widespread worldwide poverty" and "the threat of serious environmental externalities from unprecedented levels of production and consumption of goods and services," stating - as if it were fact and had already happened - that "among the negative externalities created by human activities, the cumulative emissions of greenhouse gases [of which CO2 is preeminent] have had by far the most serious consequences in the form of global climate change."
We wish Pachauri had mentioned what those already-experienced "most serious consequences" were. Has the earth warmed by a frightening amount? Absolutely not. The increase in temperature over the last century or more is only on the order of 1°C. Has it taken us to an unusual level of warmth? Absolutely not, as evidenced by the fact that the baseline from which modern warming commenced was the uncharacteristic cold of the Little Ice Age, which is judged to have been the coldest interval of the current interglacial, which has itself been deemed to have been colder than all four of the interglacials that immediately preceded it (Petit et al., 1999). Clearly, therefore, we are in the process of emerging from perhaps the coldest interglacial period of the past half-million years; and we may yet have a ways to go before we return to what would be considered a more "normal" interglacial climate.
Have Greenland and Antarctica been losing ice mass at an accelerating rate that has been causing global sea level to rise at an accelerating rate? Absolutely not. In fact, we have recently reviewed two sea level studies that indicate the rate-of-rise of global sea level over the last half of the 20th century was actually less than the rate-of-rise over the first half of the century (Jevrejeva et al., 2006; Holgate, 2007), which is suggestive of a decelerating rate of global sea level rise.
Have droughts, floods and storms of various types been growing more severe over the past century? Or have they been occurring more frequently? Absolutely not, as one can readily verify by perusing the many items we have archived under the corresponding headings in our Subject Index.
So what has been happening?
For one thing, rising temperatures and atmospheric CO2 concentrations have been helping plants almost everywhere grow more vigorously and profusely, as may be verified by reviewing the many items archived under the several continental subdivisions of the Greening of the Earth heading in our Subject Index, plus the voluminous plant growth databases archived in the Data section of our website. This phenomenon has been a great boon to humanity, and especially to "the sustainable well-being of rural communities" that ranks so high on Pachauri's list of important causes he says he supports, and for whom crop growth and vitality are of critical importance. Interestingly, however - and tellingly - he recoils against one of the most powerful forces at work in the world today that is helping to bring about that to which he pays such fervent lip service, and which has a proven track record of impressive accomplishment.
And what is that record? In our editorial of 11 Jul 2001, we describe how the Industrial Revolution's flooding of the air with CO2 has likely already resulted in mean yield increases of 70% for C3 cereals, 28% for C4 cereals, 33% for fruits and melons, 62% for legumes, 67% for root and tuber crops, and 51% for vegetables, all due to the aerial fertilization effect of atmospheric CO2 enrichment and its concurrent anti-transpiration effect, which together greatly enhance plant water use efficiency.
Not only do these phenomena benefit people everywhere, they are also of great benefit to the planet's terrestrial animals, and not only because they enhance the vegetative food base that ultimately sustains all of them, but because without the boost atmospheric CO2 enrichment gives to human agricultural production, in just a few short decades it has been estimated that humanity will have to usurp nearly all remaining cultivatable land and freshwater resources on the face of the planet just to produce the food needed to sustain our own species, leaving next to nothing for what we could call wild nature. See, in this regard, our reviews of Wallace (2000), Tilman et al. (2001) and Foley et al. (2005).
In conclusion, it would appear that Pachauri and the rest of the IPCC political crowd are their own worst enemies - and ours and nature's - when it comes to meeting the true and most pressing needs of the biosphere.
Sherwood, Keith and Craig Idso
Foley, J.A., DeFries, R., Asner, G.P., Barford, C., Bonan, G., Carpenter, S.R., Chapin, F.S., Coe, M.T., Daily, G.C., Gibbs, H.K., Helkowski, J.H., Holloway, T., Howard, E.A., Kucharik, C.J., Monfreda, C., Patz, J.A., Prentice, I.C., Ramankutty, N. and Snyder, P.K. 2005. Global consequences of land use. Science 309: 570-574.
Holgate, S.J. 2007. On the decadal rates of sea level change during the twentieth century. Geophysical Research Letters 34: 10.1029/2006GL028492.
Jevrejeva, S., Grinsted, A., Moore, J.C. and Holgate, S. 2006. Nonlinear trends and multiyear cycles in sea level records. Journal of Geophysical Research 111: 10.1029/2005JC003229.
Pachauri, R.K. 2007. Sustainable well-being. Science 315: 913.
Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.-M., Basile, I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pepin, L., Ritz, C., Saltzman, E., and Stievenard, M. 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399: 429-436.
Tilman, D., Fargione, J., Wolff, B., D'Antonio, C., Dobson, A., Howarth, R., Schindler, D., Schlesinger, W.H., Simberloff, D. and Swackhamer, D. 2001. Forecasting agriculturally driven global environmental change. Science 292: 281-284.
Wallace, J.S. 2000. Increasing agricultural water use efficiency to meet future food production. Agriculture, Ecosystems & Environment 82: 105-119.