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Floods, Forests, Food and Biofuels
Volume 11, Number 10: 5 March 2008

In our Editorial of 26 Sep 2007, we took the UK's Sir John Houghton to task for promoting the idea that to ward off catastrophic global warming and its predicted negative consequences we need to have "very large growth in renewable energy sources," among which he lists biomass -- as in biofuels -- as one of his favorite renewables. Our primary reason for chastising him in this regard was that given the increase in human population that is projected for the mid-point of this century, there will not be enough suitable land and water to grow the crops we will need to sustain ourselves at that point in time and to simultaneously support the rest of the planet's animal life. Consequently, Houghton's proposal to use even more land and water to grow biofuels will only worsen both of these problems, leading to (1) the total devastation of the world's poor, for with insufficient food to support all of humanity, the cost of simply living (i.e., purchasing basic foodstuffs) will skyrocket beyond the ability of the poor to acquire what they need to survive, and (2) it will lead to the utter destruction (i.e., extinction) of most of what yet remains of "wild nature."

Our solution, of course, was to let the evolution of technology take its natural unfettered course with respect to anthropogenic CO2 emissions, so that the aerial fertilization and water-conserving effects of the resultant increase in the air's CO2 content would enable us to produce sufficient agricultural commodities to support ourselves in the year 2050 without the taking of unconscionable amounts of land and water from "wild nature." In this editorial, we describe how this same course of action also tends to ameliorate one of the major catastrophic consequences that is predicted to accompany global warming, i.e., flooding.

In a paper recently published in Global Change Biology, Bradshaw et al. (2007) report the results of their study of the effects of the presence and absence of forests on the propensity for flooding, using data collected from 56 developing countries for the period 1990-2000. Employing generalized linear and mixed-effects models, they demonstrated that "flood frequency is negatively correlated with the amount of remaining natural forest and positively correlated with natural forest area loss." Based on an arbitrary decrease in natural forest area of 10%, for example, they report that "the model-averaged prediction of flood frequency increased between 4% and 28% among the countries modeled," additionally noting that the "unabated loss of forests may increase or exacerbate the number of flood-related disasters, negatively impact millions of poor people, and inflict trillions of dollars in damage in disadvantaged economies over the coming decades."

So that is what the world will ultimately experience if the biofuels craze continues. But if biofuels are not promoted, and if the air's CO2 content is allowed to continue to rise, we should see just the opposite trend; for not only would we not experience the increase in floods caused by forest area loss to biofuel production, we would experience the decrease in floods caused by forest area increase due to rising atmospheric CO2 concentrations, as described in our many reviews of pertinent scientific papers that we have archived under the headings of Long-Term Studies (Woody Plants) and Range Expansion (Woody Plants) in our Subject Index.

Truly, the route to the future that we have laid out would be immensely beneficial for both man and nature; for as Bradshaw et al. state in the discussion section of their paper, "halting deforestation or reducing the rate of natural forest loss should be beneficial in alleviating the incidence and severity of floods that ultimately cause undesirable societal disruption and damage to human life and property." Just as truly, they hit the nail on the head when concluding in their final sentence that "the concept of conservation of natural habitats needs to extend beyond the notion of saving imperiled biotas to include the welfare of disadvantaged humans around the world." And, we would add, allowing the air's CO2 content to continue to rise allows both man and nature to be benefited together.

Sherwood, Keith and Craig Idso

Bradshaw, C.J.A., Sodhi, N.S., Peh, K.S.-H. and Brook, B.W. 2007. Global evidence that deforestation amplifies flood risk and severity in the developing world. Global Change Biology 13: 2379-2395.