why not save energy by simply running in the park? You do some shopping on the way home. Are you concerned to choose food that is in season, has not had to be kept frozen for months and is not over-packed in climate-

Reducing GHG emissions from waste is about capturing methane generated in the landfill through the decomposition of organic materials such as food scraps, garden waste and paper. Sewage and wastewater treatment plants also release methane when they break down waste. Reduction of GHG emissions from waste can be achieved by utilising the anaerobic digestion (AD) process caused by bacteria in the absence of oxygen, for biogas production. Biogas consists mainly of methane (around 60 per cent) and CO2 (around 40 per cent) (with traces of hydrogen sulphide and ammonia). The process is exactly the same as occurs in the landfi ll anyway, but under controlled conditions. The biogas can be used for electricity and heat generation. The main limitations of such a process are high capital and operating costs, especially at large scales. Successful energy generation depends on providing a continuous supply, adequate storage and reduced transport requirements (so the schemes should
be mainly local). In theory, well-managed waste incineration plants and biogas production from disposal sites are valuable energy sources. But the technology needs to be applied more widely until uncontrolled dumps disappear. What is more worrying is excessive waste generation itself: finite resources are transformed into single-use, GHG-emitting goods that all too quickly end up in landfills.

hostile material? Home for dinner, and you may decide it is simpler and quicker to thaw some frozen vegetables, instead of cooking fresh ones on the stove. Doing the laundry means still more decisions: do you use a high temperature wash or choose a lower one that takes less power? Do you use the tumble dryer or leave the washing to dry on a clothesline? The evening is for watching TV. Hopefully it has not been on stand-by all day long, together with the DSL modem, the DVD player and the stereo. Before bed you check your emails: perhaps you have read the warning from one industry fi gure, that worldwide internet usage alone needs the equivalent of 14 power stations for the necessary computers and servers.

The net result of the exercise is perhaps surprising. Someone who does not think about the climate impact of the way they live would be responsible for emissions of about 38 kg of CO2 for a day like this. Yet somebody who thought hard could enjoy virtually the same level of comfort for a much more modest CO2 burden of 14 kg. Often that is all it takes – a conscious effort to think about the impact we are having.

THE CYCLE – REDUCE KICK THE HABIT 107