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By Robert Rapier on Dec 21, 2009 with 1 response

Let the Data Do the Talking

Although not always successful, my goal is to let data drive my conclusions. Still, we all sometimes find ourselves in debates that are based more on passion and conviction than on data. But if the data are ignored because the conviction is strong, it may be dogma driving the conclusions.

Passionate debates are fine, but passionate debates that ignore data have no business in a scientific discussion. Further, such arguments frequently degenerate because one or both sides is not listening to the other.

During such emotional debates, I have been accused of being a shill for oil and gas, or of being a shill for biomass. In fact, in the debate I will discuss here, I was called both in the same thread! I am pro-biomass. I am anti-biomass. I love the environment. I want to destroy the environment. I am a Conservative. I am a Liberal.

The thing is, my world is not a black and white place. In the right hands, a screwdriver is a handy tool. In the hands of an enraged person, it can be a weapon. Same tool, vastly different outcomes, depending on how it is used.

Biomass is also a tool in which the outcome depends on lots of different factors. And even then the answers to the questions don’t always lead to the same conclusions for everyone.

Here is what I mean by that. People die in car crashes every year. So one reaction to that is “If you don’t want to die in a car crash, then don’t ride in a car.” That is true. That is one response.

But one must then consider the impact of that response:

  • “How would this impact your mobility?”
  • “Would you still travel places, and if so, how?”
  • “Is there a bike path that you could utilize, or would you give up your automobile only to risk your life cycling next to a busy highway?”
  • In other words, what secondary conclusions result based on the response to the initial question? But another approach is to reexamine the initial question:

  • “Why do people die in car crashes?”
  • The answer may be that most people die in car crashes due to very specific issues that can be mitigated. That is not to say that this will eliminate your risk of dieing in a car crash. But if I determine that 63% of the people who die in car crashes were not wearing seat belts, then I can always wear a seat belt and improve my odds of surviving a car crash.

    This is the approach I try to take with science issues. Frequently the answers to questions are not definitive, and instead depend on any number of conditions. And in the end there will still be disagreement. Some people may feel that a 1% risk is acceptable, but that may be 100 times too high for the next person on the very same issue.

    When someone is letting their emotions drive the argument, I try to get them to confront the data. If the answer is “It won’t fit”, then I either want to see that it doesn’t fit, or I want to measure it. This was the approach that I attempted to take with Joshua Frank, the author of – Burn a Tree to Save the Planet? The Crazy Logic Behind Biomass.

    Following my recent critique – Biomass is Not Crazy Logic – Frank dropped by and left a number of comments. Not everyone wades through the comments, and the comments are really not designed for prolonged exchanges. Further, these essays are often picked up and reposted without the comments. So I thought it might be worthwhile to extract some of the comments here. (The complete responses can be found following my initial essay).

    Frank’s argument can be distilled down to this: Citing Professor Tim Searchinger, Frank argues that burning biomass creates a net addition of carbon to the atmosphere. Burning biomass creates the danger that we will cut our forests down and inefficiently turn them into energy. Burning biomass creates emissions. Therefore, the burning of biomass is crazy, and it must be stopped.

    My response can be distilled down pretty easily. I actually agree with Searchinger that there are lots of factors that have to be evaluated in the biomass/bioenergy equation. Searchinger’s point is to show that the improperly used screwdriver can be a weapon. Frank then extrapolates that position to: A screwdriver is a weapon, and therefore we must stop the spread of screwdrivers.

    Frank cites Searchinger, but Frank’s extrapolations are subjective and qualitative. Numbers are missing from Frank’s analysis. Conclusions are sweeping and rigid. He argues that there is only one way to do biomass: The wrong way.

    In the real world, the burning of biomass can present the risks Mr. Frank cites. But where Mr. Frank goes wrong is that he believes that it must present those risks. That logic does not follow. Responsible management of biomass resources can have the opposite impact of what Mr. Frank suggests.

    In the back and forth that ensued, Frank seems to be unaware that the issues he raises are known issues; that while he is bemoaning them as a reason to surrender, some are out there working on solving them.

    A perfect example of this was his frequent argument that “burning biomass creates particulate emissions.”

    JF: “Burning woody biomass produces PM25, the most deadly form of particulate matter. This is a serious public health threat. Even if you believe that biomass is carbon neutral, you cannot skate around this important, well-documented fact.”

    Regarding this issue that Frank kept trying to educate me on, here are some excerpts from a book chapter that I recently completed on Bioenergy and Biofuels from Woody Biomass:

    RR: The majority of the wood used for cooking is done over an open stove. This is an inefficient process, leading to excessive consumption of wood. Open cook stoves also result in particulate emissions. Excessive pollution from wood cooking has been identified as a risk factor in acute lower respiratory infection, the chief cause of death in children in developing countries (Smith 2000).

    So I am well aware of the particulate emission issue with biomass burning. But here was the next paragraph, in which I discussed mitigation of the particulates problem:

    RR: Modern biomass stoves have been developed that are much more efficient with respect to wood utilization. These stoves can mitigate some of the problems associated with cooking over an open fire. By operating more efficiently, the money spent for fuel, and/or the time spent collecting fuel is diminished, as less fuel is required. Because combustion is more efficient, the air pollution associated with open fires is also diminished. Due to the multiple advantages of moving to modern biomass stoves, a number of programs have emerged with the intent of disseminating these stoves to the developing world (Barnes 1994).

    In another section, I wrote:

    RR: As with wood for cooking, one disadvantage from using wood for heating is the high level of particulate emissions. Open fireplaces also suffer efficiency losses from heat exiting the chimney. The development of community advanced combustion systems (AWC) has the potential for allowing increased usage of wood for heating, because of increased efficiency and lower particulate emissions.

    So Frank is aware of a problem, but is unaware that this sort of problem can be mitigated if the framework is in effect to mitigate it. This problem has a solution, albeit many have not adopted the solutions. Frank only sees a problem.

    The biggest hang-up, though, was probably around energy balances. There was quite a bit of “it takes a lot of energy to cut trees down and haul them out of the forest.” Again, there were never any numbers associated with these kinds of comments (except for the ones I provided). I guess if you use phrases like “diesel-powered” a lot, you can infer that the energy balance is bad without ever having to crunch the numbers.

    As I told Mr. Franks, the various energy inputs in the logistical chain of taking a tree from the forest and getting it to a processing facility – or the energy inputs in the conversion process itself – are available and are used in life cycle assessments regularly. “A lot of energy” for me has numbers associated with the claim. So instead of arguing about “a lot of energy used to harvest and transport” and that no biomass process can overcome that, why not attempt to quantify that?

    Back to the chapter I just completed, I wrote a section called “Net Energy Considerations.” Here is an excerpt from that section:

    RR: When calculating the energy that one could extract from a resource, it is important to consider the energy inputs into the process, as well as the types of energy inputs.

    In that section, I spent a bit of time explaining that the net energy of a process can easily be negative, and those processes are not sustainable. I concluded that section with:

    RR: Consideration of energy inputs also highlights one of the shortcomings of biomass relative to petroleum: The energy density for biomass is much lower; less than half the energy density of oil. This is due to the fibrous nature of biomass, and the fact that the moisture content tends to be high. This has implications for recoverability of wood resources. In general, the lower the energy density of the feedstock, the closer it needs to be to the processing facility due to the energy required for transport. Economical technologies that can efficiently increase the energy density of biomass in the field are needed. Some are currently under development and will be discussed in this chapter.

    So yes, I am aware of the relationship that energy inputs have on the sustainability of the system.

    At one point Frank did actually use some numbers to show that it takes longer to grow a tree than it does to burn a tree:

    JF: “A large tree that took 20 years to go (GE trees would be less) may burn in 17 seconds (after chopped to fine pieces).”

    This must be a key concept for him, because he actually pointed it out three different times. At one point he referred to this as a fundamental fact. This leads him to the conclusion:

    JF: “Trees will be burned at a far quicker rate than it takes to replace them.”

    As a rebuttal to his “fundamental fact,” I point out that the tomato it took 60 days to grow is eaten in 5 minutes. Therefore, tomatoes are eaten at a far quicker rate than it takes to replace them and the eating of tomatoes must be stopped before they are wiped out?

    Frank made a number of other unsupported arguments such as:

  • JF: “Biomass in the US means deforestation in our national forests. Period.”
  • JF: “Almost 99% of biomass to electricity plants in the US are also burning coal or trash. That’s a huge problem.”
  • JF: “If we are going to promote biomass as a renewable, we are looking at large scale deforestation.”
  • JF: “Trees simply do NOT make for good sources of biomass for electricity. Woody debris is not a dense energy source like coal (I’m not suggesting coal is the alternative). That’s why, as you know, power plants are using other fuels with biomass to produce energy.”
  • JF: “There is no such thing as good forest management when profit is involved.”
  • It’s like arguing that red is the best color. Put some numbers to it and let’s measure it. Are 99% of biomass to electricity plants really burning coal or trash? What is the source of that claim? Or is that simply hyperbole over coal plants that have started to supplement with biomass?

    I kept wondering if he ever gave any thought to what would happen if we abandoned the use of biomass for fuel. I can tell you what would happen: In the U.S., the future would be coal until we run out of coal. (To be perfectly honest, that’s probably the case anyway). That is reality. Sure, there’s nuclear, but something tells me that this wouldn’t be his preferred outcome. In developing countries, it would eliminate the particulate emissions problem because huge numbers of people wouldn’t have any fuel for cooking.

    At one point Frank brought up the threat of genetically modified organisms (GMO). I pointed out that while my company doesn’t use genetically modified trees, I am not personally opposed to genetic engineering in principle. Nature has been genetically modifying organisms since the beginning of time, and everything we eat has been genetically modified. Every mutation (even those that aren’t expressed) is a naturally-occurring experiment in genetic engineering. This was his response:

    JF: If you are not opposed to GE (and no, cross-breeding and hybridized plants are not genetically engineered, stick to engineering because your biology stinks) then I can’t help you. GE is new to the cycle of evolution.

    That line of argumentation is certainly a tangent, but countless people are alive today as a result of genetic engineering. Incidentally, I appreciate his concern, but it isn’t my biology that stinks. I wrote that nature has been doing genetic modifications forever. That is a fact. Frank was the one who translated that as “cross-breeding and hybridized plants.” He may want to look into genetic mutations, because cross-breeding and hybridization aren’t the only things that have changed the genetics of our food.

    Ultimately when I continued to challenge his replies, it went the way emotional-arguments often go. Because I failed to yield to his subjective arguments, he concluded that I couldn’t be motivated by the science. So he threw out a couple of ad homs -

    JF: You get paid to do it. Makes much more sense why you will not address the real dangers of biomass production.; You are motivated by factors other than hard science. Biomass = paycheck. I get it.

    - and then left. In light of what he actually wrote, I found the phrase “hard science” especially ironic. Maybe I misunderstood and he was simply complaining that the science is hard?

    For the record, I don’t get paid to promote biomass. I don’t get paid to write at all. I write because I like to, and I am focused on biomass because I think it is going to have to play an important role in our energy future. It can’t be the sole solution – and I have argued the point many times that it can only replace a small fraction of our fossil fuel usage – but every analysis I have ever done suggests that it must be a part of the solution.

    At the end of the day, I try to be practical. I frequently hear people suggest that what really needs to happen is to reduce the global population by 95%. My eyes just glaze over. Those are the sorts of things that are not going to happen by politics or decree. It is navel-gazing to sit around and argue about “solutions” like this. Better to focus on solutions in the context of what is likely to actually take place once the politics have been factored in.

    This is how I view biomass. Frank can spend his time dogmatically arguing that it must necessarily be a disaster. But what is likely? It is more likely (in fact, it is certain) that we are going to continue down this path. Therefore, I think a much more productive use of time is to ask “How do we do it right?”


    Barnes DF, Openshaw K, Smith KR, van der Plas R. (1994). What Makes People Cook with Improved Biomass Stoves? A Comparative International Review of Stove Programs. Washington, DC. The World Bank.

    Smith, K., Samet, J., Romieu, I., and Bruce, N. (2000). Indoor air pollution in developing countries and acute lower respiratory infections in children In: Thorax. June; 55(6): 518–532.

    1. By alvonso daniel on August 1, 2010 at 1:27 am

      great information thanks

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