Thursday 6 September 2012

Rubbish Statistics

An infographic in an article in yesterday's Metro presents the following 'facts':

1. The average waste per person in England has fallen... to 263 kg per person per year in 2010/11.

2. During 2010, regulated waste facilities in England and Wales managed nearly 140m tonnes of waste

OK, glossing over the England-England & Wales-UK distinction:

From 1, 263 kg x 62 million people = 16 million tonnes of waste. So where do the other 124 million tonnes come from to get to the 140 million tonnes in 2?

As a reality check, we have our black dustbin emptied fortnightly with about 50 kg of rubbish in it each time, there are four of us, so that makes 312 kg each.

3. More than 40% of household waste was recycled in England in 2010/11. 50% of local authority collected waste was sent to landfill in 2010/11.

As well as the black bin, we generate probably about twice as much in recycling stuff (mainly newspapers, but also cans, bottles and plastic). So the 263 kg seems very much on the low side, and I'd guess we 'recycle' two-thirds of our waste by weight, considerably more than the 40% figure mentioned in 3. In reality, we do no such thing as recycling of course, we just separate it out nicely, which is futile as our local council does 'co-mingling', but hey, whether it really gets recycled later on, I do not know.

312 kg x 3 = 1 tonne each, times 62 million people gets us to 62 million tonnes a year, I suppose it's possible that there's as much again in industrial waste and from earthworks and construction, which might get us to the 140 million tonnes. But it's not like rocks, bricks, wood, sand and soil are in any way dangerous or harmful, you just chuck them back whence they came.

5. Every minute, 1m plastic bags are used

1 million x 60 x 24 x 365.25 = 526 billion, divide that by 62 million people means eight thousand plastic bags a year, two dozen a day, which is clearly nonsense. Maybe they mean for the entire world, which would be one-and-a-half each per week, which is perfectly plausible, probably on the low side though.

6. It takes 1,000 years for one plastic bad to completely degrade

That's quite simply not true, depending on how you define 'completely'. Or else, where are these umpteen quadzillions of plastic bags we've used over the past fifty years? Largely rotted away, that's where.

7. Each year, we generate 290m tonnes of waste

So is it 290 million or 140 million (from 2)?

8. About 2bn steel cans are recycled in Britain each year.

2,000 million cans ÷ 62 million people = 32 each per year, seems very much on the low side, but not completely unreasonable.

And so on - if the figures they quote completely contradict each other and you have to compare and contrast and do reality checks on each one, then this completely defeats the point of the exercise. I would assume that some of their figures are correct (a painted clock is right twice a day), but which ones?

7 comments:

Anonymous said...

Worstall just said "I know he’s talking about a mansion tax (better dealt with by LVT..."

Now you've done it, Timmy!

http://timworstall.com/2012/09/06/so-how-does-a-wealth-tax-work-then/

Mark Wadsworth said...

RA< I have risen to the bait.

Brian, follower of Deornoth said...

"It takes 1,000 years for one plastic bad to completely degrade"

So ten plastic bags take 10,000 years, then?

Mark Wadsworth said...

BFOD, presumably yes.

Bayard said...

"6. It takes 1,000 years for one plastic bad to completely degrade"

So how come when you try and remove one from your hedge, it just falls into little bits which are impossible to clear up? Perhaps it dates from Saxon times. It's amazing what you learn on the internet; I didn't know King Canute used plastic bags. Perhaps he wore them on his feet when he was doing that trick with the sea.

Mark Wadsworth said...

B, exactly. I often notice plastic bags which have blown into trees and snagged there, they usually disappear after a few days.

If they were that resilient, then all trees would be full of snagged plastic bags by now.

If the buggers said "it takes thirty years for a plastic bag to fully degrade" then I might have believed them (whether that is true or not).

Kj said...

The official statistics for England is here:
The generation of household
waste continued to decrease between the financial years 2009/10 and
2010/11, with a 0.9 per cent reduction to 23.5 million tonnes.


The weight of household
waste generated in the year April 2010 to March 2011 in England, in kilograms per person, was 449 kg per person. Of this total, 186 kg was recycled, composted or reused whilst 263 kg was not.


The total amount of local authority collected waste generated has decreased
by 1.3 per cent to 26.2 million tonnes... In 2010/11, household sources accounted for 89.5 per cent of local authority
collected waste generation.


In 2010, construction and demolition waste was 77,4 million tonnes. And <a href="http://www.defra.gov.uk/statistics/environment/waste/wrfg03-indcom/> Commercial and industrial waste</a> was 47,9 million tonnes. Seem to add up roughly to the given figures, but poor presentation. The Defra-site is full of statistics that are only people like me can appreciate...