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Webinar: Greenhouse Gas Emissions from Plastics in the Environment
Tuesday, 09 October 2018, 2:00
Tuesday, October 9, 2018. 2:00PM. Webinar: Greenhouse Gas Emissions from Plastics in the Environment. Sarah-Jeanne Royer, University of Hawai'i at Manoa. Sponsored by NOAA. More information here.
Mass production of plastics started nearly 70 years ago and the production rate is expected to double over the next two decades. While serving many applications because of their durability, stability and low cost, plastics have deleterious effects on the environment. Plastic is known to release a variety of chemicals during degradation, which has a negative impact on biota. Here, we show that the most commonly used plastics produce two greenhouse gases, methane and ethylene, when exposed to ambient solar radiation. Polyethylene, which is the most produced and discarded synthetic polymer globally, is the most prolific emitter of both gases. The study demonstrated that as the surface area of the plastic increases due to weathering and break-down in the ocean, there is a tremendous increase in methane and ethylene off-gassing: For example, LDPE powders off-gases methane 488 times more than when the same weight of LDPE is in pellet form. In addition, low-density polyethylene emits these gases when incubated in air at rates ~2 times and ~76 times higher than when incubated in water for methane and ethylene, respectively. Our results show that plastics represent a heretofore unrecognized source of climate-relevant trace gases that are expected to increase as more plastic is produced and accumulated in the environment.