From New Scientist magazine:
1. If I switch the light on and off every time I enter and leave a room, does this use more energy than leaving it on all evening?
Switching the light on and off does saves energy, but there is a catch. Every time you flip the switch, the bulb takes a jolt of electricity, which shortens its life.
Studies by the Electric Power Research Institute in Palo Alto, California, found that turning low-energy compact fluorescent bulbs on and off at frequent intervals can shorten their lifespan by as much as 75 per cent.
21GREENTIP: Leave energy-saving bulbs ON but only if you will be out of the room for less than 15 minutes.
2. How clean does the pizza box have to be for it to be recyclable?
Likewise cans and bottles?
According to the Waste and Resources Action Programme (WRAP), based in Banbury, UK, pizza boxes are often not recyclable. That’s because grease from the toppings contaminates the cardboard, making it useless to paper mills – though it can still be composted.
Such impregnation is not a problem when it comes to cans and bottles. Nevertheless, they should be rinsed to remove food remnants so as not to attract vermin.
Plastic should also be clean, and lids removed from bottles so they can be squashed flat. WRAP recommends rinsing waste items in old washing-up water to save energy.
3. Are laminated juice cartons recyclable?
Yes – but only if you separate them out. Placing cartons lined with polyethylene or aluminum foil into your ordinary paper recycling devalues the load and, depending on the mill it reaches, may mean it ends up in landfill.
4. What’s the most fuel-efficient way to drive?
Smoothly. Avoid dramatic braking and acceleration and use cruise control if you’ve got it. Move through the gears as quickly as possible, changing up before you hit 2500 revs per minute (2000 rpm for a diesel).
Where possible, drive at a steady 55 miles per hour (90 kilometres per hour). It is up to 20 per cent more fuel-efficient than driving at 75 mph. Check your tyre pressure once a month because underinflated tyres can raise fuel consumption by 6 per cent.
Don’t carry excess baggage. Each extra 25 kilograms decreases fuel efficiency by 1 per cent.
And avoid short trips – a cold engine uses twice as much fuel as a warm one.
5. How environmentally damaging is barbecuing?
Tristram West from Oak Ridge National Laboratory in Tennessee has calculated that on 4 July – when over half of all American households fire up their barbies – the grills release 225,000 tonnes of CO2.
The emissions from these estimated 60 million barbecues would still be less than 1.5 per cent of the nation’s daily output.
That is equivalent to burning 2300 acres of forest. He says that if you do choose to barbecue, the most eco-friendly method is to use charcoal as opposed to the propane burners favoured by most Americans. Food grilled over charcoal made from locally grown coppiced wood may actually have a smaller carbon footprint than if it were cooked conventionally, since sustainably grown wood is carbon neutral and transport is minimised.
More at Dumb Ecoquestions you were afraid to ask
Stumble It!
