How green is my household?

Disasterous week

Hi Hilary here, feeling much better (in spite of the title of the blog). Many thanks to all who wrote or posted such encouraging messages in response to my 'Negative thoughts' post. It was certainly a turnaround for the Cadman-Gall household for Bruce to be posting positive thoughts, I'm usually the cheery one, whereas he frequently behaves as though he's auditioning for 'Grumpy old men'.

We've had a frustrating week in terms of our carbon emissions. First, Bruce and I managed to double our emissions on a trip to the Southern Highlands last Saturday. We went up to visit an elderly relative, but that morning the owner of the B&B we had booked rang and persuaded us that we'd best take Bruce's gas-guzzling 4-wheel drive rather than my little Echo, because they were experiencing such wild weather. In the end we encountered nothing more drastic than heavy rain, and would have been fine in the Echo!

On Sunday afternoon I decided to water one of the circles in my permaculture garden. I drip-irrigate the garden using a tank of water that's filled from our dam via a petrol-driven pump. When the tank is full (as it was), it takes about 2 hours of watering to get about 2 litres flowing from each dripper, which is all the plants need. Three days later Bruce went out to feed the chooks and found he was standing in a bog - the whole tank had been emptied onto the one circle, wasting water and petrol, and not doing much good to the plants.

Finally, Bruce and I heat our studies using flat radiant heaters (advertised as 'a hot water bottle for the office'). They use very little energy, because they just heat the person not the room. However, the downside of this is that it's really easy to forget to turn them off. Last week Bruce left one running all night, so it was busy radiating heat while he slept. All of this has been increasing our carbon footprint unnecessarily, which is most frustrating.

On a positive note, a colleague and I had to go up to Sydney this week for work. Rather than both flying there and back, I went up by bus and my colleague joined me the next day, driving up in the company Echo. This meant that once our work was finished we could drive back together. So we not only saved the company some money  but also generated substantially less greenhouse gas emissions. It certainly created some discussion with our clients, none of whom had considered the bus as an option for travelling between Sydney and Canberra.

Positive thoughts

Hi, Bruce here, I thought I should put a more positive spin on our efforts after reading Hilary’s ‘Negative thoughts' post.

The thing I’m feeling positive about is our food. Most carbon calculators only address easily measured and monitored items such as petrol, electricity and gas usage. However, research by Professor Manfred Lenzen of Sydney University, shows that fossils fuels only account for 25 % of our per capita carbon emissions. What about the other 75%?

Professor Lenzen has developed a personal greenhouse gas calculator, from which he calculates that the production, packaging and transport of food causes 20% of our carbon emissions. He identified seven food and one drink category, and allocated a ‘greenhouse price’ per dollar spent to each of these. Beef products have the highest ‘price’ at 8.9 per $ spent, while fruit and vegetables have the lowest at 1.4.

To calculate your food ‘greenhouse’ budget, you need to know your annual expenditure on each of these categories. I did this for a month (March) and extrapolated to get an (approximate) annual figure. I then compared our results with Lenzen’s national averages for each category.

I was appalled to find that our food emissions were 5.2 tonnes — above the national average of 4.9 tonnes.  We don’t eat beef, we shop locally, rarely buy imported foods, grow a lot of veggies, buy mainly organic food and don’t over eat, all of which should have lowered our emissions, so how could we be higher than average?

I then remembered that Prof Lenzen’s work was based on 1994/95 prices, and I was using 2007 prices, thus inflating the results (his calculator is currently being updated). Since the CPI has increased by 36.5% since 1995, I adjusted our expenditure for each of the categories, and came up with a revised figure of 3.3 tonnes, well below the national average — what a relief, and something to feel really positive about!

But wait, there’s more. The organic food we buy doesn’t use high-energy inputs such as fertilisers, herbicides and pesticides, so will produce less emissions than non-organic food. This is not factored into the calculator. Also, our low food miles will reduce emissions relative to the national average, so I’m giving us a 10% reduction in emissions for both food miles and organic shopping, which brings our annual food-based emissions down to a mere 2.6 tonnes.

I’ll do another month’s recording and take an average, just to make sure we have got it right, but I’m pleased to report that Hilary cheered up enormously on hearing the results so far.

Negative thoughts

Hi, Hilary here, under a bit of a cloud. When we started this exercise last October it seemed fairly straightforward — we'd work out our carbon dioxide emissions, reduce them as far as possible and then offset the rest, probably by planting trees on our property. The reality has been more complicated.

In spite of Bruce's herculean efforts, we haven't managed to put a figure on our emissions, even down to the nearest tonne of CO2.

Reducing emissions has been a bit more positive, in that we've managed to reduce our energy use (at least in summer) and our petrol consumption (mostly by using Bruce's gas-guzzling truck less and my little Echo more). Food is still a challenge — we haven't been able to answer some basic questions. For example:

• Is it more environmentally friendly to buy milk in 1-L cardboard containers lined with foil or in 2-L plastic recycleable containers?
• In making our own yogurt, is it better to buy milk (in whatever type of container!), heat it and use live yogurt to make a new batch; or to buy a foil packet of dried milk with culture (imported from NZ) that simply needs to be mixed with water and then left in a thermos overnight?
• When buying rice, is it better to buy Australian-grown rice, which is almost certainly unsustainable, given the crop's high need for water in this dry continent; or to buy Thai-grown rice, with its accompanying food miles? (Or should we just stick to potatoes?).

However, what has really made me feel depressed is a talk on carbon offsetting that I gave to my work colleagues. In investigating the topic, I found that the carbon accounting process used in offsetting is based on the type of economic accounting that Enron was using, and is about as dodgy. I was even more alarmed when I discovered the amount of carbon being released into the atmosphere through deforestation. Basically, in the time it's taken me to write this post, logging has released about as much CO2 as 150,000 people flying from London to New York. This makes the issue of how to make planet-friendly yogurt pale in comparison!