Carbon Credits
Problems
 

Carbon credits seem like a great way to help both developing and developed countries.  However, critics claim that using them might have unintended consequences.  To understand why this might be so, let us review what we have learned over the last several weeks. The main idea behind carbon credits is that trees are a sink for carbon dioxide.  As we saw in last week's lab, plants photosynthesize more carbon dioxide out of the air than they respire back into it while they are alive.  However, once a plant dies, organisms begin to break down the plant, respiring the sugars stored in it back into the atmosphere as carbon dioxide.  Thus, if a tree is allowed to go through its natural stages of seed to sapling to mature tree to a dead tree that becomes nutrients for new trees, then no carbon dioxide is being stored, i.e. trees in a natural forest are a zero sum factor in removing carbon dioxide. Of course, there is a way to make trees be a positive force in carbon dioxide removal: do not let the trees decay back into the soil.  This can be achieved by cutting down the mature trees before they die and using as much of the tree as can be used for lumber or some other commodity that does not allow the carbon to be respired.  This is what causes some of these critics to make their claim.  The economics of the situation will cause developing countries to cut down their natural forests in favor of tree farms, since in is only in this type of forest that carbon is actually being positively sequestered.  They also fear that the tree farms that are created will be of non-indigenous species.  A fast-growing tree, such as eucalyptus, will sequester carbon at a greater rate than most native species, and thus, allow the grower to claim a larger carbon credit.  If this tree is cut before it can decay and used as lumber, then the grower will get more money for its carbon credit, as well as getting money for using the tree as lumber.  For a cash strapped developing country, the economic incentive will not be to preserve the native forest, but to use the land for growing lumber  of non-native species and getting carbon credit dollars, to boot.

Forests as Carbon Sinks

As it currently stands, the U.S. has decided against signing the Kyoto Protocols (although we did sign a non-binding agreement in 1992 that said that we would lower greenhouse gas emissions).  This decision by the Bush Administration has angered many countries, who see the absence of the U.S. in this agreement effectively making it a worthless document.

 

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Topic: Carbon Credits Date: November 17, 2000 Summary: One of the biggest debates emerging from the global warming treaty discussions taking place in the Hague is whether or not the terms of the 1997 Kyoto Climate Change protocol will allow the U.S. to meet most of its obligations by planting or preserving forests that suck up carbon dioxide. As NPR's John Nielsen reports, delegates from Europe and elsewhere are determined that nothing of the kind should happen (http://www.npr.org). (5:00) Link: http://www.npr.org/ramfiles/atc/20001117.atc.08.ram Requires RealPlayer

Capstone Activity
Instructions

For this module's Capstone Activity, we will be examining the idea of Carbon Credits. In the first two weeks of this laboratory module you saw how vegetation can sequester carbon in its tissues, and how the processes of photosynthesis and respiration affect the cycling of carbon dioxide. By integrating these activities with this week's calculator exercise, you will determine the number of trees that would be needed to offset your personal carbon dioxide emissions. Complete the activities and questions on the Capstone Activity sheet.