Clipping Board » Environmental Pollution & Change ─ How dirty the human heart is, how dirty the environment will be...
Update Date: 2009/04/15 03:11 Yan Jiyu / Comprehensive Report
Biofuels have gained significant environmental fame in recent years, with many believing they can reduce net carbon dioxide (CO₂) emissions. The rationale is that crops like sugarcane, corn, rapeseed, and wheat, which provide the raw materials for biofuels, absorb CO₂ through photosynthesis during their growth. Therefore, burning these fuels would not result in a net increase in CO₂ emissions, helping combat global warming.
However, this may be wishful thinking. According to *The Economist*, a recent report commissioned by the International Council for Science (ICSU)—whose incoming president, starting April next year, is Taiwan’s former Academia Sinica President Yuan-Tseh Lee—reveals that biofuels not only fail to mitigate global warming but may actually exacerbate it. The key lies in another greenhouse gas: nitrous oxide (N₂O).
As early as 2007, Dutch Nobel Prize-winning chemist Paul Crutzen pointed out that the scientific community had severely underestimated nitrous oxide’s role in accelerating global warming. Moreover, cultivating biofuel crops releases large amounts of N₂O, completely offsetting any environmental benefits and even causing negative effects. Dr. Howarth, a contributor to the report, noted that while Crutzen’s calculation methods are controversial, his fundamental conclusions are correct.
Nitrous oxide, also known as "laughing gas," has mild anesthetic properties and is commonly used as a combustion enhancer in modified cars. Though far less notorious than CO₂ in the context of global warming, its greenhouse effect is 296 times stronger per unit mass. Nitrous oxide is a natural byproduct of the nitrogen cycle, but modern agriculture’s heavy use of nitrogen-rich fertilizers has led to rising N₂O emissions. Corn, with its shallow roots and limited nitrogen absorption period, is classified as the top "nitrogen-leaking crop."
Professor Townsend of the University of Colorado is studying human impacts on the nitrogen cycle. Preliminary findings suggest that changes in the nitrogen cycle are occurring faster and more drastically than the widely discussed carbon cycle. Townsend and colleagues have launched the International Nitrogen Initiative to better understand nitrogen cycle changes, mitigate their negative effects, and ultimately manage nitrogen like other pollutants.
Beyond exacerbating the greenhouse effect, first-generation biofuels made from food crops also disrupt food market supply and demand, leading to shortages in some regions. Researchers and industries are now focusing on developing second-generation biofuels using agricultural waste such as discarded wood, rice and wheat straw, corn stover, and recycled dairy products, aiming to create truly sustainable and commercially viable alternative energy sources.
Source: http://tw. news. yahoo. com/ article/ url/ d/ a/ 090415/ 4/ 1hv25. html
Biofuels May Worsen Global Warming
Biofuels have gained significant environmental fame in recent years, with many believing they can reduce net carbon dioxide (CO₂) emissions. The rationale is that crops like sugarcane, corn, rapeseed, and wheat, which provide the raw materials for biofuels, absorb CO₂ through photosynthesis during their growth. Therefore, burning these fuels would not result in a net increase in CO₂ emissions, helping combat global warming.
However, this may be wishful thinking. According to *The Economist*, a recent report commissioned by the International Council for Science (ICSU)—whose incoming president, starting April next year, is Taiwan’s former Academia Sinica President Yuan-Tseh Lee—reveals that biofuels not only fail to mitigate global warming but may actually exacerbate it. The key lies in another greenhouse gas: nitrous oxide (N₂O).
As early as 2007, Dutch Nobel Prize-winning chemist Paul Crutzen pointed out that the scientific community had severely underestimated nitrous oxide’s role in accelerating global warming. Moreover, cultivating biofuel crops releases large amounts of N₂O, completely offsetting any environmental benefits and even causing negative effects. Dr. Howarth, a contributor to the report, noted that while Crutzen’s calculation methods are controversial, his fundamental conclusions are correct.
Nitrous oxide, also known as "laughing gas," has mild anesthetic properties and is commonly used as a combustion enhancer in modified cars. Though far less notorious than CO₂ in the context of global warming, its greenhouse effect is 296 times stronger per unit mass. Nitrous oxide is a natural byproduct of the nitrogen cycle, but modern agriculture’s heavy use of nitrogen-rich fertilizers has led to rising N₂O emissions. Corn, with its shallow roots and limited nitrogen absorption period, is classified as the top "nitrogen-leaking crop."
Professor Townsend of the University of Colorado is studying human impacts on the nitrogen cycle. Preliminary findings suggest that changes in the nitrogen cycle are occurring faster and more drastically than the widely discussed carbon cycle. Townsend and colleagues have launched the International Nitrogen Initiative to better understand nitrogen cycle changes, mitigate their negative effects, and ultimately manage nitrogen like other pollutants.
Beyond exacerbating the greenhouse effect, first-generation biofuels made from food crops also disrupt food market supply and demand, leading to shortages in some regions. Researchers and industries are now focusing on developing second-generation biofuels using agricultural waste such as discarded wood, rice and wheat straw, corn stover, and recycled dairy products, aiming to create truly sustainable and commercially viable alternative energy sources.
Source: http://tw. news. yahoo. com/ article/ url/ d/ a/ 090415/ 4/ 1hv25. html