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Scientists to Congress & Obama: count the carbon in biomass

Nathanael Greene

Posted May 24, 2010

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Today a group of leading scientists from across the country sent a letter to congressional leaders and Obama officials urging them to carefully count the carbon from biomass burned for energy as part of a comprehensive climate bill or any other leg    islation or regulation.   The letter makes abundantly clear that failing to do so risks sacrificing forests around the globe and putting more pollution into the atmosphere, not less.

As my colleagues have written about (here, here and here more generally), the American Power Act (APA) proposed by Senators Kerry and Lieberman provides a solid framework for reducing our global warming pollution and investing in a cleaner economy. Unfortunately, as proposed, the bill would turn a blind eye towards emissions from biomass combustion, threatening to significantly undermine the bills carbon reduction goals. (For some basic thoughts on how the bill should be amended see this fact sheet put out by NRDC and other groups after the House climate bill passed.)

I did a little video late last year explaining the fundamental flaw in the approach that the APA would take. The letter from the scientists puts it clearly:

Replacement of fossil fuels with bioenergy does not directly stop carbon dioxide emissions from tailpipes or smokestacks. Although fossil fuel emissions are reduced or eliminated, the combustion of biomass replaces fossil emissions with its own emissions (which may even be higher per unit of energy because of the lower energy to carbon ratio of biomass). Bioenergy can reduce atmospheric carbon dioxide if land and plants are managed to take up additional carbon dioxide beyond what they would absorb without bioenergy…. On the other hand, clearing or cutting forests for energy, either to burn trees directly in power plants or to replace forests with bioenergy crops, has the net effect of releasing otherwise sequestered carbon into the atmosphere, just like the extraction and burning of fossil fuels. That creates a carbon debt, may reduce ongoing carbon uptake by the forest, and as a result may increase net greenhouse gas emissions for an extended time period and thereby undercut greenhouse gas reductions needed over the next several decades. 

Like the climate bill adopted by the House last year, APA would explicitly exempt power plants and industry facilities from having to hold emissions permits for the CO2 pollution coming out of their smokestacks when they burn “renewable biomass.” The term “renewable biomass” was defined in the Energy Independence and Security Act of 2007 as part of the updated Renewable Fuel Standard. While that original definition is far from perfect, it does prohibit the most destructive sources of biomass (think clear cutting public forests or plowing under endangered habitat). Unfortunately both the House ACES bill and APA would redefine renewable biomass to mean just about any source of biomass.  That needs to be changed. The proposed APA definition contains absolutely zero protections for at risk habitat, forests, or grasslands on private lands and lacks needed safeguards on our federal forests as well.   For example, under the current definition of biomass chopping down and grinding up forests that are home to imperiled species is not allowed.  Nor is plowing under the few remnants of native praire left in this country (only about 4% of the original remain).  In contrast, under the APA definition, both these activites are not only allowed, they are encouraged.   (For more on what is at stake see this fact sheet.)

So between blowing open the definition and turning a blind eye to the emissions, you end up with a biomass loophole big enough to drive a truck through—a truck loaded with big, old trees that should be keeping carbon out of the air and providing habitat to animals struggling to adapt to the changing climate.

Most importantly, Congress needs to understand that they’re not just creating a biomass loophole, they’re actively encouraging biofuels refiners, utilities and industry to burn more biomass. We have the Renewable Fuel Standard, and I’ve written a lot recently about the corn ethanol tax credit. The House climate bill includes a renewable electric standard that would require the use of renewables, which on the whole is an important step, but the biopower part of this is another big incentive for burning biomass. And then of course the climate bill itself creates a big incentive for burning biomass by holding companies accountable for the pollution caused by burning fossil fuels but not counting the carbon released from burning biomass. It will only be natural for companies to use the stuff they don’t have pay for.

This is like squeezing on a balloon—if we only squeeze on part (the fossil fuel emissions), we’re just going to shift the emissions to the other part (the biomass emissions).

So how big a deal is the biomass loophole? Well the Department of Energy’s Energy Information Administration recently published its Annual Energy Outlook for 2010, and it provides some insight. Unfortunately, taking its lead from Congress, EIA does not count the emissions from the combustion of biomass in its total greenhouse gas emissions, but they do add up these emissions. I’m going to write more about EIA’s data tomorrow, but the scale is eye-popping:

… [I]ncluding direct CO2 emissions from biomass energy combustion would increase the 2008 total for energy-related CO2 emissions by 353 million metric tons (6.1 percent). In the AEO2010 Reference case, including emissions from biomass would increase the projected 2035 total for energy-related CO2 emissions by 813 million metric tons (12.9 percent).

EIA’s number for 2020 is about half a billion metric tons of which 215 million is an increase over 2007, the earliest year they report. For a little context, that increase would be equal over 20% of the total reductions targeted for 2020 by both the House ACES and Kerry-Lieberman APA. And this represents the BAU reference case forecast without the added incentives for biomass combustion in the climate bills.  Now, of course, direct emissions are not the same as the careful net emissions accounting that the scientists are urging Congress to embrace, but changes in soil carbon, nitrous oxide emissions from fertilizer applications, or the limited and slow regrowth of burned up biomass can easily make bioenergy just as polluting as fossil fuels especially over the next 20-30 years.

Bottom line, EIA’s data clearly shows that the carbon emissions associated with bioenergy threaten the very basic goal of climate legislation. We’re talking about a block of pollution equal to roughly half of the reductions the bill is supposed to provide. Biomass sourced carefully could really be part of the solution but, how can we hope to get good biomass or solve global warming if we don’t count all the source of pollution as pollution. You can’t fix a problem if you don’t first acknowledge that it exists.

It’s time for Congress to act and pass a comprehensive climate bill. They should follow the scientists and the science and account for biomass emissions carefully.

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John JamesMay 24 2010 11:55 AM

What about the fact that the plants that produce biomass renewables obsorb the carbon they release and then some in the next growing cycle.

rick johnMay 24 2010 12:11 PM

How about the scientists in sweden?
Ethanol and biogas use in Sweden shows a large climate benefit, performing up to 140 percent better than petrol and diesel, even when so-called direct and indirect soil effects are included, a new research study shows.

I wander who these scientists are associated with, sounds like Big oil trying to prolong their greed more and more, when is enough, enough?

Marie CuratoloMay 24 2010 04:20 PM

I do believe that some biomass energy sources do offer a good alternative to fossil fuels, however, in response to what Rick John said, perhaps it is not the use of biomass energy sources, but more so the scale and the extent to which it could be used if monetary and legal incentives are provided, as in the APA. In other words, it could be hugely beneficial over petroleum, but what happens when big industry takes over and needs to use it on a scale it has yet to see? I think one thing that this article illustrates is the potential of biomass to become the next oil; widely exploited to an equally unsustainable extent.

tony lovellMay 24 2010 05:16 PM

Imagine if we had a process to remove billions of tonnes of CO2 from the atmosphere safely, quickly and cost-effectively - while at the same time building soil, reversing desertification, boosting biodiversity, enhancing global food security and improving the lives of hundreds of millions of people in rural and regional areas around our planet?

We do - it's called changed grazing management and soil carbon.

Please take a look at the presentations on to learn more.

BIObloggerMay 25 2010 11:29 AM

I am amazed at the fossil thinking of these “scientists.”

1) There is a fundamental difference to the carbon content of the atmosphere between using fossil carbon and biogenic carbon sources. Fossil carbon combustion adds GHG that was never part of the carbon cycle before – "carbon positive." Biogenic carbon combustion simply recycles that which is already in the atmosphere – "carbon neutral." We have been pollution our carbon cycle with fossil resource carbon for 150 years - that's the GHG dilemma.

2) GHG emissions is only one scientific reason for replacing fossil fuels with biogenic. Others include: fossil is not renewable (biogenic is); fossil distillation is getting more toxic (biogenic is getting cleaner); direct fossil land and water use change is severely impacting ecology (i.e., oilspills and tar sands)

3) The NRDC needs to embrace biomass conversion facilities. They will provide environmental clean-up and funding for timberland thinnings, reforestation, hurricane knockdown recycling (vs. methane generation from decay), flood demolition, invasive species control, landfill mitigation, etc.

This doesn’t even begin to cover the environment, pollution, and biodiversity costs of present and future strategic commodity resource wars like Iraq.

Someone needs to rethink their carbon accounting to differentiate fossil vs. biogenic impacts on the carbon cycle.

Chris PellerinMay 25 2010 01:31 PM

There is a 47-megawatt biomass electric generating facility that is in the process of getting permitted in the next town over from me. According to the developer's numbers in his permit documents, the plant will burn 500,000 green tons of wood every year. This is the equivalent of about 24 cords of wood per hour (perspective: homes heated by wood might use 7 cords of wood per heating season). Along with many other hazardous air pollutants, fine particulate matter, and NOx, the plant would emit 500,000 tons of CO2 per year from the stack (not including emissions from the chain saws, chippers, and trucks hauling the wood to the plant). Due to the vast amount of energy lost to evaporating moisture from wood, these plants are in the neighborhood of 25% efficient. To me, it seems like a huge waste when you consider that these trees that have been sequestering carbon for decades will be incinerated in the blink of an eye. There are no guarantees that the forests removed for fuel will be replanted.

Harrison PettitMay 25 2010 07:03 PM

Carbon accounting is a complex business, and life cycle analysis makes clear that not all biomass has the same carbon foot print. The science is still very immature when it comes to measurements of indirect land use effects, so broad guidelines need to be created that encourage the use of biomass that clearly provides carbon neutrality. Clear cutting mature forests creates a carbon debt, while harvesting sustainable volumes of wheat straw or corn stover do not. Short rotation woody biomass or plantation energy crops provide a huge benefit over fossil fuels. We should not hesitate to encourage their development and use.

Brooke ColemanMay 28 2010 12:47 PM

People need to really look hard at what NRDC and these scientists (some of whom are not afraid to take oil industry dollars to publish articles and conduct research against biofuels) are saying here.

First, they point out the problem of just assuming that any CO2 emissions coming from burning biomass is absorbed by the growth of the next cycle of biomass. This is a problem, because it's sometimes true and sometimes not true. There should be some credit there, because unlike fossil fuels, producing biomass DOES absorb carbon in the production phase. But right now, it's not treated dynamically.

The absurdity comes in the proposed solution. They then go on to say we need "proper" carbon accounting. Sounds reasonable. Except, the way to make it proper, they say, is to penalize biomass for indirect land use change (this solution is not the focus of the letter, but underlies it in several places). This is Nathanael's balloon youtube, in which the use of biomass for energy in one place theoretically pushes existing food and feed agriculture to a new place. In other words, biomass should pay for the land expansion effect of its use. This is just another way of saying that bioenergy should pay for the land use impacts of the food and feed industry (because they theoretically pushed them there).

No wonder change does not happen. Our change makers want to address the problem of bioenergy not being held accountable for their actual land impacts by making them accountable for someone else's land impacts. Not their own true, direct land use impacts, but someone else's land effects.

That's the answer Nathanael? And people are supposed to be surprised and outraged that bioenergy companies and agriculture opposes this?

Russ FinleyMay 29 2010 12:08 PM


Let me try an analogy. Let's say that you steal a farmer's field from him (as is often done to poor farmers around the world). The farmer is forced by your actions to clear a patch of rainforest or grassland to feed himself and his family.

Applying your argument, you should not be blamed for the 'indirect" land use change caused by the displaced farmer.

John and BIOblogger,

Google "Dunning-Kruger." The reason you don't agree with these "scientists" isn't because you are better informed on the subject.


You make a good point about the link provided by Rick John. The study basically concludes that biofuels don't scale.

Everybody seems to missing the main point. Biofuels only represent about 2% of global energy use today. Expansion of their use is when the problems start:

----"each type of biofuel has different limitations in production volumes. In order to avoid negative effects, it is important to know where this boundary lies. Rapid and significant increases in production of biofuels from food crops could result in negative indirect land use changes, he said. “There is a limit, but we are not there yet.”----

This study only covered fuels used in Sweden:

----"Currently, biofuels made from Swedish raw materials and sugar-cane ethanol imports account for about five percent of total fuel use in Sweden."----

For example, if use climbs to the point that the sugar cane plantations dedicated to Swedish fuel run out of land and have to start clearing new land, the game is over. Thirty thousand square miles of prime farmland was usurped for corn ethanol in the US last year.

"I do believe" is the basis of religion (not to mention a line from the Wizard of Oz). That is why we have science, and scientists.

Brooke ColemanMay 31 2010 08:34 PM

That's not an analogy. That's an example. But ok, let's just agree on a "theft exception," in which the land thief pays for the victim's land use impacts in the specific case of when the land is stolen. But back to how indirect land use is actually predicted and assessed. The models are economic models, in which the choices to convert land to one thing or another are elective, and based on price. In the econometric case, you got me: I think it's absurd to have bioenergy paying for the land use impacts of the food and feed industry. It's like saying that a Prius should pay for the carbon emissions of a Yukon because increased demand for lots of hybrids reduced demand for gasoline, which in turn reduced the price of gasoline, which in turn catalyzed a price-induced response of increased Yukon sales (because gas prices are lower). The question isn't whether proponents of carbon shifting (like NRDC) will fail to sell this concept, it's how long it will take them to fail, and to what degree this bad idea will set the entire carbon agenda back. We need to get back to the idea of responsible supply-chain accountability, and stop trying to finesse the absurd: that we should fix non-accountability by making bioenergy pay for someone else's emissions.

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