Those amazing Idsos who run the Center for the Study of Carbon Dioxide and Global Change review a paper recently published in AMBIO: A Journal of the Human Environment by Mulder et al. (2010), who assess the energy return on water invested (EROWI) of several renewable and non-renewable fuels.
In the paper, provocatively titled “Burning Water,” the Mulder team find that “the most water-efficient, fossil-based technologies have an EROWI one to two orders of magnitude [10 to 100 times] greater than the most water-efficient biomass technologies, implying that the development of biomass energy technologies in scale sufficient to be a significant source of energy may produce or exacerbate water shortages around the globe and be limited by the availability of fresh water.”
The Idsos note that these findings “will not be welcomed” by those who promote biofuels as a means of combating the alleged national security risks of global climate change.
We often hear, for example, that climate change will increase the risk of “water wars” by intensifying summer heat and drought. There’s not much evidence to support this alarm. About 90% of global fresh water consumption is for agriculture. As British scientist Wendy Barnaby found to her surprise when she set out to research a book about the coming “century of water wars,” nations in water-stressed regions typically do not come to blows but instead cooperate and import “virtual water” in the form of grain, leaving more water available for drinking and bathing. Even in the water-stressed, conflict-prone, Middle East, nations do not go to war over water. Nonetheless, to the extent that water stress undermines stability and peace, government policies ramping up biofuel production are likely a “cure” worse than the supposed disease.
In addition, some biofuel policies can increase food prices and world hunger, fostering instability and strife, especially if scaled up enough to make a meaningful difference in global carbon dioxide (CO2) emissions.
Princeton researchers Stephen Pacella and Robert Socolow estimate that avoiding 1 gigaton (gt) of carbon emissions per year by 2050, by replacing gasoline with biofuels, would require 250 million hectares of high-yield energy crop planations, “an area equal to about one-sixth of the world’s current cropland.”
Let’s put this in perspective. One gigaton of carbon = 3.67 gt of CO2. Achieving the EU/UN emission stabilization target of 450 parts per million would require global CO2 emissions to decline roughly 38 gt below the baseline (business as usual) projection by 2050. In other words, the 3.67 gt reduction in CO2 that Pacala and Socolow say we can get via biofuels would achieve less than 10% of the reduction required to meet the target. Not a whole lot of environmental bang for all that land area buck. Indeed, dedicating 250 million hectares to energy crop production would likely squeeze many species out of their habitats.
Source: Stephen Eule, Scale and Scope of the Challenge to Reduce Greenhouse Gas Emissions, Institute for 21st Century Energy, U.S. Chamber of Commerce, February 2009
Note also that significant research indicates that converting grassland and forest land into biofuel plantations increases net greenhouse gas emissions over many decades by releasing the carbon stored in forests and soils. Growing biofuel on 250 million hectares of land might very well emit more CO2 than the gasoline it replaces.
The larger point, though, as Dennis Avery explains, is that the world is not well-fed now, and the demand for food and feed on farmlands is expected to more than double by 2050. Requiring biofuel production on 250 million hectares would be a recipe for disaster. Putting the equivalent of one-sixth of current cropland off limits to food production represents a much bigger decline in global agricultural productivity than is anticipated from drought in high-end global warming scenarios.
Warmists warn that climate change is a “threat multiplier” or “instability accelerant.” However, the national security risks of climate change policy likely exceed those of climate change itself.
For further discussion, see my CEI paper, DOD Should Consider the National Security Risks of Global Warming Policies, and economist Indur Goklany’s comprehensive study, Trapped Between the Falling Sky and the Rising Seas: The Imagined Terrors of the Impacts of Climate Change.
* When I first posted this, I failed to notice that Pacala and Socolow were measuring emission reductions in tons carbon whereas Stephen Eule was measuring reductions in tons CO2.