Archive for March, 2011

Plants to Plastic?

Wednesday, March 16th, 2011

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This week, PepsiCo announced the development of a 100% plant-based PET plastic bottle, of which they will produce several hundred thousand in 2012.  Provided success in their test drive they will eventually use only this technology for their bottles, completely replacing the petroleum-based PET plastic that is currently used.  The bottle is made from bio-materials such as switch grass, pine bark, and corn husks.  A University of Pittsburgh study argues, however, that plant-based plastics are not necessarily more environmentally friendly than petroleum-based ones.  According to the study, plant-based plastics are more biodegradable, less toxic, and make better use of renewable resources than other plastics, but the extremely energy intensive nature of agriculture and the environmental costs from using chemicals to grow the plants, make it questionable as to whether it is actually a good alternative.  In the future, PepsiCo plans to use byproducts from their other brands such as orange rinds (Tropicana) and potato peels (Frito Lay) to make these bottles, which takes away the argument that the bottles are not more environmentally friendly.  Provided this new technology proves to be feasible, the environmental effects will be huge.  For perspective, Coca-Cola has currently produced 2.5 million bottles made of 30% plant materials, which is said to be the equivalent of saving 3 million gallons of gasoline.

With rising prices of oil, bio-plastics alternatives are moving towards becoming the cheaper plastic.  Cereplast, a company that makes such plastics, says that once oil reaches $95 a barrel, their plastics are cheaper to make than regular plastics.  According to http://www.oil-price.net/, oil prices are slightly higher than this already ranging from $97-110 per barrel.  As for the environmental effects, Frederic Scheer, Cereplast’s owner says, “Each time you create one kilo of traditional polypropylene, you create 3.15 kilos of carbon dioxide. When we create one kilo of bio-propylene, we create 1.40 kilos of carbon dioxide, so clearly you have a substantial saving with respect to greenhouse gases, creating a much better carbon footprint for the product.”  A transition from petroleum-based plastic to plant-based may not be as far-fetched as it seems.

-Kelly

The Buzz on Bees

Thursday, March 10th, 2011

In class this week we discussed conventional and sustainable agriculture, and the challenges that prevent sustainable agriculture from becoming more prevalent.  One of the issues we discussed was the fact that conventional agriculture appears to be cheaper than sustainable agriculture; however, this is due to the fact that conventional agriculture doesn’t factor in all of the hidden costs into the price.  One such hidden cost was the billions of dollars a year in environmental damages, health problems, and the loss of wildlife, which reminded me of a research project I worked on last year at Central Virginia Governor’s School.  My group looked at the declining number of honeybees and how if nothing is done, it will affect the biosphere over the next 50 years.

Around the world a decline in honey bee populations has become a pressing environmental issue.  Honeybees are important as they help sustain biodiversity, pollinate approximately one-third of the global food supply, and contribute to approximately 90% of sexual reproduction of angiosperms.  According to this article, “of the 100 crop species that provide 90 per cent of the world’s food, over 70 are pollinated by bees.” Reasons for decline include habitat fragmentation, agriculture, grazing, and Colony Collapse Disorder.  As humans expand further into natural habitats for developments or agriculture, they reduce the number of plants that can function in pollination.  Conventional agriculture is based on the large-scale growth of one species, which displaces native plants and changes the biodiversity of a region.  Grazing destroys the bees’ natural habitats and also decreases native plant diversity as animals selectively feed on certain plants.  Colony Collapse Disorder has been observed in 35 US states so far and is characterized by the sudden death of adult worker bees when they’re away from the hive.  Scientists are still investigating causes for CCD; however, some probable causes include decreased nutritional fitness and chemical contamination.  Nutritional fitness is determined by the number of honey bees that must share food and how healthy the plants are that are available for pollination.  The use of pesticides can lead to a high death rate in bees and herbicides can kill native flora that they rely on for food.

The effects of honeybee decline are costly and far reaching. Currently, commercial pollination by honeybees is a $15-20 billion industry.  As there are less pollinators available to pollinate flowers, fewer get pollinated and as a result there is decreased seed and fruit production, which leads to increased costs of production and greater demand causing market prices to skyrocket.   As part of our project, we did a  mathematical analysis taking into account birth and death rates for a healthy bee population with a starting number of 1.5 million and discovered that in 50 years the number would grow to 2.7 million; however, when using the numbers for the sick bee population, the population drops to 273,000.  Using these numbers, we were able to model the effects on crop production over 50 years, which we found to be a 44% decrease in apples, broccoli, carrots, and onions; a 32% decrease in alfalfa/hay/seed and a 3% of soybeans.

Unfortunately, with conventional agriculture, the human response to a decline in crop yield may be simply to convert more land into farmland to make up for the decrease in crop profits.  This would only make the problem worse as habitat fragmentation and mono-culture increase.  The effects of a decline in bee population are huge and it is only one of many problems conventional agriculture contributes to.  Therefore, it is important to implement sustainable agriculture practices, such as crop diversity and the efficient use of inputs, such as pesticides.

-Kelly