I don't understand how some authors claim that forests remove carbon from the atmosphere and so if you use the same land to produce and burn biofuels then that zero-carbon cycle is somehow worse for the environment than the natural cycle. Isn't it obvious that in the long run a forest has to be carbon-balanced, it isn't removing net carbon from the atmosphere but essentially all of the carbon taken up by plants eventually gets returned to the atmosphere when those plants die, decompose, etc.? If there were a net removal of carbon from the atmosphere then over long time periods each forest would be sitting on a huge pile of carbon. Of course, there is some fossil fuel production and thus carbon storage over a period of millions of years, but that seems insignificant on the time scales we're discussing. Can someone who's read these papers explain how they address this?
On Tue Feb 10 2015 at 3:59:40 PM Andrew Lockley <[email protected]> wrote: > Poster's note : Whoops. This would be funny if it wasn't so tragic. > > > http://ns.umich.edu/new/releases/22668-a-closer-look-at-the-flawed-studies-behind-policies-used-to-promote-low-carbon-biofuels > > A closer look at the flawed studies behind policies used to promote > 'low-carbon' biofuels > > Feb 05, 2015 > > Nearly all of the studies used to promote biofuels as climate-friendly > alternatives to petroleum fuels are flawed and need to be redone, according > to a University of Michigan researcher who reviewed more than 100 papers > published over more than two decades. > > Once the erroneous methodology is corrected, the results will likely show > that policies used to promote biofuels—such as the U.S. Renewable Fuel > Standard and California's Low-Carbon Fuel Standard—actually make matters > worse when it comes to limiting net emissions of climate-warming carbon > dioxide gas. > > The main problem with existing studies is that they fail to correctly > account for the carbon dioxide absorbed from the atmosphere when corn, > soybeans and sugarcane are grown to make biofuels, said John DeCicco, a > research professor at U-M's Energy Institute. > > "Almost all of the fields used to produce biofuels were already being used > to produce crops for food, so there is no significant increase in the > amount of carbon dioxide being removed from the atmosphere. Therefore, > there's no climate benefit," said DeCicco, the author of an advanced review > of the topic in the current issue of Wiley Interdisciplinary Reviews: > Energy and Environment. > > "The real challenge is to develop ways of removing carbon dioxide at > faster rates and larger scales than is accomplished by established > agricultural and forestry activities. By focusing more on increasing net > carbon dioxide uptake, we can shape more effective climate policies that > counterbalance emissions from the combustion of gasoline and other liquid > fuels." > > In his article, DeCicco examines the four main approaches that have been > used to evaluate the carbon dioxide impacts of liquid transportation fuels, > both petroleum-based fuels and plant-based biofuels. His prime focus is > "carbon footprinting," a type of lifecycle analysis proposed in the late > 1980s as a way to evaluate the total emissions of carbon dioxide and other > greenhouse gases associated with the production and use of transportation > fuels. > > Numerous fuel-related carbon footprinting analyses have been published > since that time and have led to widespread disagreement over the results. > > Even so, these methods were advocated by environmental groups and were > subsequently mandated by Congress as part of the 2007 federal energy bill's > provisions to promote biofuels through the U.S. Renewable Fuel Standard. > Shortly thereafter, parallel efforts in California led to that state's > adoption of its Low-Carbon Fuel Standard based on the carbon footprinting > model. > > In his analysis, DeCicco shows that these carbon footprint comparisons > fail to properly reflect the dynamics of the terrestrial carbon cycle, > miscounting carbon dioxide uptake during plant growth. That process occurs > on all productive lands, whether or not the land is harvested for biofuel, > he said. > > "These modeling errors help explain why the results of such studies have > remained in dispute for so long," DeCicco said. "The disagreements have > been especially sharp when comparing biofuels, such as ethanol and > biodiesel, to conventional fuels such as gasoline and diesel derived from > petroleum." > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
