Word: carbonic
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...effects of a major biofuel expansion over the coming century and found that it could end up increasing global greenhouse-gas emissions instead of reducing them. In the second paper, another team of researchers led by Tim Searchinger of Princeton University uncovered a potentially damaging flaw in the way carbon emissions from bioenergy are calculated under the Kyoto Protocol and in the carbon cap-and-trade bill currently being debated in Congress. If that error in calculation goes unfixed, a future increase in biofuel use could end up backfiring and derailing efforts to control global warming, according to the paper...
...problem is that biofuels are treated as if they were 100% carbon neutral, even though they are clearly not. When ethanol is burned, for instance, it still releases CO2 into the atmosphere. After all, the plants that go to make biofuels are made of carbon, just as oil and other fossil fuels are. Further, the use of biofuels would reduce total greenhouse-gas emissions only if their creation were to increase - or at least not displace - existing plant growth, which naturally takes carbon out of the atmosphere. For example, if the wood chips left over from logging were used...
...that's rarely how it works in most biofuel production today. Instead, a long-standing forest might be clear cut in Indonesia and replaced with a plantation of palms to make biodiesel. That's where the accounting error crops up: we should assess the carbon lost in deforestation when we measure the greenness of biofuels, but that's not how it works under Kyoto, which simply exempts all CO2 emissions that come from using biofuels. CO2 emissions resulting from deforestation or other changes in the way we use land are not evaluated at all. The result is a huge...
...effects of that error have been modest so far. But if the U.S. adopts a cap-and-trade system with the same mistake, or if the world agrees to a truly global successor to Kyoto, the blowback could be enormous. As long as biofuels are incorrectly treated as 100% carbon neutral, they'll represent an economical way for companies to offset their greenhouse-gas emissions and comply with a tightening carbon cap. One study estimates that if the world were to meet a 50% "cut" in global greenhouse gases by 2050 under the current calculations, the necessary biofuel-crops expansion...
There are other side effects as well. Melillo's paper points out that if biofuels scale up rapidly, they could end up displacing cropland and pasture, which would impact global food supplies and increase land-based carbon emissions. Melillo found that if biofuels were linked to a global policy to stabilize carbon concentrations in the atmosphere at 550 parts per million - a modest goal - we would need more land for biofuel production by the end of the 21st century than is currently used for all food crops. Worse, all the fertilizer needed to grow those bioenergy crops would increase emissions...