The Department for Environment, Food and Rural Affairs' (DEFRA's) new packaging recycling targets highlight the growing importance of overall carbon emissions, rather than simply material weight, when assessing the benefits of recovery and broader sustainability.
The targets include an increase for glass from 78% this year to 81% in 2010, and for aluminium from 35% to 40%. This follows a consultation period, prior to which slightly higher figures were discussed for these material streams, says DEFRA.
But alongside these weight-based targets, the new figures spell out the estimated carbon savings that will result if these targets are met.
Waste management consultant David Perchard says: "Moving on to carbon does seem to be a sensible broadening of criteria, although it is not always easy to measure."
He agrees that carbon calculations and lifecycle analyses (LCAs) in general can yield different results. As he puts it: "Few people who commission LCAs are disappointed with the results. But it does at least give you the basis for intelligent debate." And he contends that weight data is equally open to manipulation.
Parts of industry have for some time been claiming that a move away from a purely weight-based focus and towards carbon calculations is overdue. Dick Searle, chief executive of the Packaging Federation, says: "The lightweighting agenda is running out of steam." So the Courtauld Commitment, whereby brand-owners and retailers have undertaken to reduce the weight of their packaging, should instead focus on "net environmental impact", he argues.
The glass industry is especially keen to see a shift away from weight as the exclusive criterion for judging sustainability. According to director general of British Glass David Workman, some of the Courtauld signatories are starting to reassess these criteria. "Energy input and carbon emissions have to be the main considerations," he says.