The writer Mark Twain liked to point out that statistics usually are not far from being “damned lies.” But for measuring recycling rates and proposing recycling goals, statistics are seen as useful tools -- though perhaps too much so, since they are so prone to uncertainty, recalculation, or misuse.
One recent example of their use is the change in the way PET recycling rates are measured by the U.S. Environmental Protection Agency. Under its new methodology, the 2010 U.S. PET recycling rate was recalculated to provide an alternative figure to the traditional “gross" rate (29.2% in 2010), which indicates the amount of PET items collected for recycling. The new stat is a lower, “net" rate (21%) reflecting the percentage of PET material that's actually recovered.
The net rate reportedly accounts for the contaminating impact of non-PET bottle caps and other materials commonly collected with PET containers (though some of the discounted caps and lids are themselves being recycled). Even though this recalculation is explainable, the 21% figure may tend to deflate some of the optimism about recycling progress in the U.S.A. (Meanwhile, there’s also a heated argument going on about U.S. film recycling figures.)
In the U.K., there have been issues concerning percentage goals for future recycling. The British Plastics Federation has reportedly questioned how a recent government goal for recycling 57% of plastic packaging by 2017 can be achieved. The BPF argues instead that a 35% target is more realistic, and it does makes sense, especially when recyclers must deal with issues like poor mixed-plastic bale quality.
Calls for much higher recycling rates will always be used to motivate change, but at some point they ring hollow. After all, does anyone remember a recycling target called for five years ago, and how close industry/society came to reaching it? (And does anyone believe that “true” recycling rates can be measured to within even a few percentage points of uncertainty?)
Mike Tolinski is the author of Plastics and Sustainability, published in Oct. 2011 by Wiley-Scrivener, and he is Contributing Editor for Plastics Engineering magazine of the Society of Plastics Engineers in the USA. His views have been shaped by his engineering, university, and journalism experience in the plastics and manufacturing industries over the past 21 years. You can follow Mike and be alerted on blog updates via Twitter.