I agree the quality of these numbers is not brilliant. But the particular problem you allude to (lumpiness of import data) would apply whether it was tonnage or bag numbers. Also, the previous data were built up from both imports (about three quarters of bags) and local production (about one quarter), so there is less scope for this being an issue.

I also agree that there are incentives for these numbers being unreliable - but I still maintain that there expiry of the industry code would be a reasonable explanation for some turn around in the decline (and I do agree that forty percent growth is still a whopping turnaround).

I wonder whether composition is a factor. The original report assumed 5.5g a bag. The ten bags I had in my pantry tonight weighed an average 8g each. So if my (major supermarket) bags were more representative of bags used by Australian we would be using 3.3b now, not the 4.8 they estimate. And if 8g was more representative in 2002, we would have used 4b not 6b bags. Plenty of room for composition effects to distort the trends.

A far more productive target for the reduction of plastic waste is in the packaging industry: so many things are wrapped in heavy plastic shells, contain superfluous non-degradable or recyclable plastic bags, and are then placed in boxes. So unnecessary.

they’re quite popular in some parts of Melbourne (yuppie environment syndrome — the 15.0L/100K Toorak tractor is fine but the bags arn’t — I doubt this exists in Broome), and some places would like to phase them out completely. I’m in the same position as Andrew in that if they don’t give them to me at all (I collect about 50% of my groceries with them — the rest go into my backpack), I’m just going to buy them for my rubbish anyway.

I can’t find this latest report on the web, but it’s clear that the earlier numbers are pretty dodgy, using such methods as extrapolating numbers of bags from bag imports as measured by tonnage. This creates obvious problems in when the imports arrive - if for example a large shipment that would normally have arrived in December 2006 instead arrived in January 2007 that would help explain why 2006 was low and 2007 high, with no implications for actual bag consumption.

Also, it requires an estimate of bag weight. If as is likely the light bags used by supermarkets are declining as a % of all bags the average weight of bags should be increased, leading to a lower total number of bags in the estimates.

However, one input into a theory behind these numbers is that the Australian Retailers Association Code of Practice for the Management of Plastic Bags expired at the end of 2005. This code (http://www.ara.com.au/fileadmin/sitesections/policy/codes/ARABAGCOde.pdf ) aimed to reduce use by 50% by 2005 through retailers undertaking consumer awareness campaigns, promoting re-usable bags and staff training. I don’t think they were obliged to actively do anything after 2005.

Still, a 40% rise in one year is pretty big – but it just returns per capita use in 2007 (on these reported numbers to 230 each) the same level as in 2004 (about 235 per person).

What does all this mean? In spite of greenie propaganda about almost non-existent impacts on sealife (greenmail) and government intervention (greentape), industry self -regulation (greenwash) does the wise old Australian consumer actually like plastic bags?

Based on the numbers in the article and previously published figures plastic bag use in Australia from 2002 to 2007 would be about:

Year bags (billion)
2002 5.95
2003 5.2
2004 4.7
2005 3.9
2006 3.36
2007 4.84

One theory: the numbers are right but the evangelists who run plastic bag policy are trying to whip up hysteria?

Rudd’s team are good at this kind of distraction. The ‘alcohol violence crisis’, the ‘homeless crisis’ and anything else they can find. It’s politically pretty savvy.

It’ll be interesting to see how they handle the larger and more expensive issue of carbon emissions. Presumably by promising something for another government in the future. the Blair/Brown government’s response. Hopefully they’ll read some Bjorn Lomborg.