Thursday, April 23, 2009

Plastic Bags Get a Qualified Tick

In Australia, the State Government of South Australia intends to ban plastic bags from 2010 [ I think that is the date]. I wrote something recently that took a swipe at that policy........plastic are visible litter but really are relatively less damaging to the environment than some other options.

Now there has been a serious examination of the life cycle impact of various shopping bags here in Australia. The "green bag" is widely used, and I have seen them in many places in SE Asia as well, being used by locals, who probably got them while holidaying in Australia. I used two tonight for some shopping myself. They are great.......but you need to remember to take them with you!

The precis of the report is below. It is VERY interesting reading and sure to be controversial, and I have no doubt will incur the ire of the great unwashed greenies.

Hey fellas, get real........there are a few sides to the story!

Plastic bags better than underused reusable bags
Monday, 20 April 2009
Reusable shopping bags could be worse for global warming than single use plastic bags if they aren’t reused as often as they could be. But single use paper bags have the highest impact across all environmental categories, said a life cycle assessment for Woolworths on the environmental impact of shopping bags.

It also found that, regardless of material, all shopping bags could be diverted from landfill depending on available infrastructure and consumer behaviour.The environmental impacts of shopping bags by the Sustainable Packaging Alliance and RMIT University researchers assessed the impacts of seven different types of shopping bags including single use plastic bags, two types of reusable bags and degradable plastic bags.The bags fared differently according to the environmental impact being considered. For example, although single use paper bags were the overall worst offender, they have “the lowest impact in litter”.

The study examined the impact of the bags through their life cycle over eight categories including land use, water use, solid waste, global warming and fossil fuel use. “The life cycle which was modelled includes the environmental impacts associated with raw material sourcing and production, manufacture of the bags and their disposal at end of life (i.e. landfill, recycling, compost or litter),” the study’s authors say. “A qualitative review of disposal and recovery options for each bag was also undertaken.”

In support of the obvious point that a reusable bag isn’t a greener option unless the consumer actually repeatedly uses it, the study found the benefits of a reusable bag was “highly sensitive” to the number of times it is used because of the resources it consumes in its life cycle.The study assumes reusable bags are durable for use 104 times, or once weekly for two years. If it is only used half that number of times, it’s worse for global warming than single use plastic bags.

“The implication for retailers is that consumers should be encouraged to reuse existing bags rather than continuously buying new bags,” it says.

The researchers said about 3.9 billion single-use plastic shopping bags were consumed in the country in 2007 and many were reused “for shopping and alternative uses, such as bin liners and food storage”. Only some 16% are recycled and most of those that aren’t end up in landfill, but it is “not necessarily an environmental problem, because most landfills are designed to minimise degradation by compressing waste and removing leachate”.

The bags make up less than about 1% of litter, but attract much attention because they are “highly visible and persistent in the environment” and pose a potential hazard to wildlife.
So........if you really want to make difference, use your reusable bag! This report also seriously undermines the SA Government position. The whole approach is a bit odd, as SA has been a great user of recycled plastics for making "plastic timber" - for fence posts, and similar uses as a replacement for some CCA treated pine posts, which now seem less attractive environmentally. Plastic waste including plastic bags went into that process. Surely we can improve recycling of plastic bags!

This whole issue has a long way to go yet!

Saturday, April 11, 2009

Turf Management - Two for One

Older turf areas often need some serious renovation. Typically, one uses verticutting, coring, top dressing, even close mowing, as typical operations to remove excess organic matter, a common problem in the tropics particularly.

There are many pieces of equipment which can do some of this work.

Recently, our local council has purchased a new piece of equipment which seems to be very capable of adding two of these operations together.

With verticutting and a flail mower, it seems to do an excellent job of removing excess organic matter in a single pass.