Forest carbon does not fully offset fossil carbon

mongabay.com
December 3, 2007

As policymakers meet in Bali, Indonesia to discuss various mechanisms for mitigating greenhouse emissions, a tropical ecologist from Sri Lanka warns that one ton of forest carbon is not equal to one ton of fossil carbon when it comes to using offsets to fight global warming. The implications: considerably larger forest areas (preferably old growth since it has higher carbon values than plantations) would need to be protected and reforested than are presently anticipated by most policymakers.

Dr. Ranil Senanayake, chairman of Rainforest Rescue International, says that fossil carbon, which has been locked up for tens of millions of years, cannot be treated the same as carbon from biotic sources, which is ephemeral by comparison, lasting at most a few tens of thousand of years. Factor in the potential impact of climate change on forest biomass and the likelihood of deforestation or forest fires, and there are few guarantees that carbon presently sequestered in a forest will stay that way. Further, most carbon offset schemes fail to account for differences in longevity of carbon stored in different types of vegetation.

"The longer any material stores sequestered carbon, the more valuable it is to the initiatives that sequester carbon to reduce the atmospheric concentration," Dr. Senanayake told mongabay.com. "Consequently, time must be accepted as a value variable when trading in sequestered carbon. Within the biological system, carbon is taken up in many ways though photosynthesis or carbonate cycles with each having internal processes that operates at different rates. For instance, the photosynthetic activity of plants takes carbon dioxide out of the atmosphere and fixes it as a solid state in organic matter creating biomass. While all plants sequester carbon, trees and woody plants are most efficient in producing resistant compounds such as lignin."

Old growth tropical rainforest stores more carbon than the plantations that often replace it. Rainforest in Uganda

"The sequestering value of wood is in its durability, its capacity to withstand the attacks of decay organisms," he continued. "Archeological finds often demonstrate wooden artifacts dating back about 1000 years. In America, a durability standard has been devised by using White Oak as the standard. In this method of evaluation White Oak is given a rating of (100). Wood with higher scores such as Red Cedar (150-200) or Black Locust (150-250) is more durable. Woods with a lower score such as Hemlock (35-55) or Birch (35-50) are less durable."

A second key point, says Dr. Senanayake, is that "the origin and state of all carbon compounds differ in terms of the contribution to climate change."

"The second problem in the evaluation of carbon can be traced to the work of some modern modelers. They missed or ignored a crucial element in evaluating the dynamics of the carbon cycle discussed above in terms of sources and sinks. Sources are those carbon compounds that decay into carbon dioxide and sinks are carbon compounds made from carbon dioxide," explained Dr. Senanayake.

"This represents a fundamental flaw in the current model. In evaluating relative values of carbon sinks, the source of carbon is critically important. What differentiates the setting value of carbon dioxide is the cycling time of the source of carbon and the retention time of the sink. In this respect, there are two major cycling systems to be considered as carbon sources, the biological and geological," he continued.

"In our rush to create the new carbon economy, this very simple and fundamental fact has been ignored. Carbon that cycles through living systems represents a fixed proportion of the planetary carbon. The planetary carbon is the total found in mineral, organic and inorganic carbon."

Between 2000 and 2005, the planet lost 6 million hectares of primary forests per year. Rainforest in Colombia.

"The carbon that enters the biotic cycle has, in most cases, been a product of photosynthetic activity. In geologic time, carbon is added to the atmosphere through tectonic processes. In an attempt to remove this excess carbon dioxide from the biosphere a small proportion is fossilized and enters the lithosphere never to interact with the biosphere again. This small proportion is translated into vast quantities of fossilized carbon and removed from the biotic/atmospheric cycles. These fossil pools have lifetimes of tens or hundreds of millions of years."

"Thus the value differential produced by these cycles, the biotic and the fossil, must be recognized. The biotic carbon operates on time frames of tens or hundreds of thousands of years. The fossil carbon in tens or hundreds of millions years. Further fossil carbon is not interactive with the living or biotic cycle. Fossil carbon entering the biotic cycle is the fundamental reason as to why there is the accelerating greenhouse effect. the growing of trees to compensate for fossil carbon and paying the same price as biotic carbon is tantamount to 'carbon laundering'. There is no way to compare the carbon from oil and coal with the carbon from a forest. One has a space in the biotic cycle the other does not."

"My concern is that if we allow the laundering of fossil carbon at a mere $10-$15/ton we will not make any change in the resources for response as well as on reducing the impact. If the sequestration value of biotic carbon is $10.00/ton (considering a 100,000 year residence time for any given time pool) the corresponding value of fossil carbon must be $1000/ton at a minimum. To liquidate either must entail a cost equivalent to its value and the price paid for sequestration must reflect this. If we get this discussion into the global bureaucratic agenda, we could make a real change, by empowering the work that we both agree on."

"I have been attempting to get the different carbon pools recognized by the international system for over ten years, but the oil industry and the 'forestry' industry have been blocking it. The attached paper might be of use. If you need a short clear article (or an interview) I will be happy to do so. The logical conclusion to accepting this reality is that the fossil industry will have to pay over $1000- $400.00 ton to get their carbon fixed. Think about it, the carbon in the biotic pool is sequestered for 100,000 years max. So if we are raying $10.00 per ton to fix biotic carbon generated as a result of liquidating the asset (forest clearing, agricultural conversion), Thus if we look at the fossil pool that is sequestered for times exceeding 10-100 million years. The liquidation of this stock and its sequestering must cost at least $1000 a ton."

Carbon Laundering

Dr. Senanayake says that the current system, which treats forest carbon the same as fossil carbon, is akin to "carbon laundering."

"Allowing carbon from fossil sources to gain the same value as biotic carbon by cycling it through a tree is nothing short of 'Carbon Laundering' very much the same as money laundering. Residence times for biotic carbon is measured in hundreds of thousands of years, while fossil carbon is measured in times of tens of millions years. To make matters worse the perverse system adopted today does not recognize time as a value variable. The concept of 'incremented carbon' does not value the time that carbon is sequestered for, only the carbon sequestered through human interventions is. Thus it is profitable to cut down an old growth forest and replace it with a quick growing plantation."

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