To answer this question, Idso and Idso (2000) determined that world population in 2050 will likely be 51% greater than it was in 1998, but that world food production will likely be only 37% greater, even when including anticipated improvements in agricultural technology and expertise that should occur in the interim.  Although these results would normally spell Trouble with a capital T, the Idsos determined the projected food shortfall could be overcome - but just barely - by the benefits anticipated to accrue from the aerial fertilization effect of the concomitant rise in the air's CO2 content.  ... if the air's CO2 content is allowed to continue its upward trend unimpeded by government actions, such as those specified in the Kyoto Protocol.  In this regard, however, the anti-CO2 crowd has branded the colorless, odorless, tasteless - but highly beneficial - trace gas a "pollutant," the aerial increase of which must be stopped at all costs.  And we do mean all costs.

Consider, for example, the study of O'Neill and Wexler (2000), which is described in our Editorial Limiting Life in the Name of Climatic Salvation.  These climate alarmists extraordinaire calculated the externalities or costs and benefits "associated with the birth of a child that fall on society," including "the increased CO2 abatement costs necessitated by an additional birth."  The net result, according to them, is a cost of $4,400 per birth in less-developed countries and $28,200 per birth in more-developed countries.

How serious are these people?  Let us count the ways.  One: O'Neill & Wexler say "externalities cause inefficiencies in the economy, and their existence is often viewed as grounds for intervention in order to improve total social welfare."  Two: they say "efficiency would be served by imposing a tax on births equal to the net value of the externality."  Three: they say "the existence of a greenhouse externality strengthens the case for population policies that lower fertility."  Four: they say "a hypothetical social planner acting in the interests of all parents could increase social welfare by dictating a fertility rate different from the rate parents would choose on their own."

Schneider (2001) is also an advocate of freedom-bashing measures, as we indicate in our Editorial The Crux of the Climate Policy Debate.  He states, for example, that the "real cure" for the ongoing rise in the air's CO2 content involves "curbing the consumption of the rich and the population growth of the poor."  This he proposes to do via institutions with "the authority to enforce responsible use of the global commons," where responsible use would be defined by folks such as he and O'Neill & Wexler.  These institutions, he further says, "would need the resources and authority to make and monitor changes," leading to the necessity of nation states being willing to "cede some national sovereignty to international authorities for the global good."

Fortunately for us, the anti-CO2 hysteria of recent years was not around when the first coal-fired steam engine chugged down the tracks.  Why?  Because many of us would not even be here today if CO2 scaremongers had squelched the Industrial Revolution.  Without the enhancement of vegetative productivity provided by the aerial fertilization effect of the CO2 produced by the engines of industry, there simply would not have been enough food produced to sustain all our forebears.

In our Editorial Hey, CO2!  What Have You Done for Me Lately?, we describe a CO2 depletion study that broaches this subject (Mayeux et al., 1997), in which two wheat cultivars were grown with adequate and less-than-adequate amounts of water.  The results of this experiment demonstrated that the 100-ppm increase in atmospheric CO2 concentration experienced over the past century and a half should have increased the grain yields of the two wheat cultivars by approximately 72% under well-watered conditions and 48% under water-stressed conditions, for a mean all-condition CO2-induced yield increase on the order of 60%.

Based on the voluminous yield-response-to-CO2 data summarized by Idso and Idso (2000) for the world's major food crops, these results suggest that the Industrial Revolution's flooding of the air with CO2 has resulted in mean yield increases of 70% for other C3 cereals, 28% for C4 cereals, 33% for fruits and melons, 62% for legumes, 67% for root and tuber crops, and 51% for vegetables.  These are huge productivity increases, about which most people are totally oblivious; yet without them, the planet would not be able to sustain the population it does today.  And without the benefits that increasing concentrations of atmospheric CO2 can provide for our crops in the years ahead, the earth will not be able to sustain the projected population of the planet less than fifty years hence.

So what is the outlook for the future?  In a study entitled "the end of world population growth," Lutz et al. (2001) foresee the planet's human population peaking at about nine billion people around the year 2070, after which they project a slow decrease in global population.  Based on the tight correlation between atmospheric CO2 concentration and human population noted by Idso (1989), we have calculated - in our Editorial The End of Atmospheric CO2 Growth - that the atmosphere's CO2 concentration would also top out at that time, somewhere in the vicinity of 420 ppm, after which it too would decline.  And this unforced natural CO2 mitigation phenomenon is much more effective than what Schneider and O'Neill & Wexler have claimed is needed.

In closing, we note that (1) rising atmospheric CO2 concentrations pose no threat to the planet's climate, (2) they are responsible for the very existence of a good many of us, (3) they are needed to support projected increases in human population, and (4) as mankind's numbers level out and begin to decline several decades from now, so too will the air's CO2 content decline in like manner.  Naturally.

References
Idso, C.D. and Idso, K.E.  2000.  Forecasting world food supplies: The impact of the rising atmospheric CO2 concentration.  Technology 7S: 33-56.

Idso, S.B.  1989.  Carbon Dioxide and Global Change: Earth in Transition.  IBR Press, Tempe, AZ.

Lutz, W., Sanderson, W. and Scherbov, S.  2001.  The end of world population growth.  Nature 412: 543-545.

Mayeux, H.S., Johnson, H.B., Polley, H.W. and Malone, S.R.  1997.  Yield of wheat across a subambient carbon dioxide gradient.  Global Change Biology 3: 269-278.

O'Neill, B.C. and Wexler, L.  2000.  The greenhouse externality to childbearing: A sensitivity analysis.  Climatic Change 47: 283-324.

Schneider, S.H.  2001.  Earth systems engineering and management.  Nature 409: 417-419, 421.