Continuing from the previous blog I posted yesterday, here
are three more eco questions and answers:
Can I save the planet
by staying slim?
It is unlikely. A research by Phil Edwards and Ian Roberts,
from the London School of Hygiene and Tropical Medicine, published in The Lancet (vol 371, pg 1661) linked
obesity and global warming. Their argument was that obese people consume
approximately 18% more calories than the average and their greater mass means
their vehicles uses more fuel (remember yesterday's blog mention of heavier
baggage requiring more fuel?). Therefore, policies to encourage walking and
cycling would not only improve people’s health but would also be good for the
planet. In theory, such measures would result in short-term benefits, but in
the long run they would be offset by the fact that people who stay in shape are
likely to be healthier and live longer; this would mean they would be emitting
tonnes of CO2 for every extra year of their lives. Therefore,
staying trim is great for you, but is not likely to benefit the planet.
What is the most
energy-efficient way to defrost my fridge-freezer, and is a self-defrosting
fridge more eco-friendly?
The frost in your freezer forms when warm air condenses and
freezes on the cooling coils. Self-defrosting fridges normally use more energy
than manual models because their coils are automatically heated every few hours
to melt any frost that forms on them. However, a manual defrost fridge is only
better if we defrost it before the frost starts to take over (let’s face it how
many of us do this?). This is because the coils have to work harder to cool the
air if they are covered in ice. How often you need to defrost depends on how
often you open the door and the humidity of the air. As a general rule though,
you should defrost when the ice gets to 5 millimetres thick. The best way to do
this is to turn off the freezer, place pans of hot water inside to speed up
melting and then remove the big bits of ice with a plastic scraper. This means
that, apart from leaving the ice to get 10 times thicker than the recommended,
most of us have been doing it right all along. I gave up on the defrosting
ritual a long time ago and invested in a frost-free fridge freezer. You can buy
these now with energy efficiency A. Fridge-freezers are said to be the
appliances that uses the most energy in a household (around 20% of the total
energy consumption), so well worth investing in an energy efficient model.
damaging is barbecuing?
It has been estimated that on 4th July, when all
American households fire up their 60 million barbecues they release 225,000
tonnes of CO2, which
is still less than 1.5% of the USA’s
daily output. However, this is the equivalent to burning 2300 acres of forest.
Oak Ridge National Laboratory in Tennessee,USA, suggests
that the most eco-friendly way to use a barbecue 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 conventionally cooked food, since sustainably grown wood is
carbon neutral and transport is minimised.
Check out the reports section of Cabi’s Environmental Impact
database for latest reports on man’s impact on the environment.
Source: New Scientist No. 2682, vol 200, Nov 2008.