阅读下列短文,从每题所给的四个选项中,选出最佳选项。
How often do you travel by plane?
How much electricity do you use?
These days everyone is worried about the size of their carbon footprint.In order to reduce global warming we need to make our carbon footprints smaller.But how much CO 2 are we responsible for?
A new book by Mike Berners Lee(a leading expert in carbon footprint)might be able to help.How bad are bananas? The Carbon Footprint of Everything looks at the different things we do and buy and calculates the amount of CO 2 all of the following created: the ingredients the electricity used in the brewery the equipment the travel and commuting of the beer and the packaging.It's amazing how many different things need to be included in each calculation.And it's frightening how much carbon dioxide everything produces.
But all of this can help us decide which beer to drink.From Berners-Lee's calculations it's clear that a pint(568ml)of locally-brewed beer has a smaller carbon footprint than a bottle of imported beer.This is because the imported beer has been transported from far away and it uses more packaging.The local beer only produces 300g of CO 2 but the imported beer produces 900g! So one pint of local beer is better for the environment than three cans of cheap foreign lager from the supermarket.
Berners-Lee has even calculated the carbon footprint of cycling to work.Nothing is more environmentally-friendly than riding a bike surely? Well it depends on what you've had to eat before.To ride a bike we need energy and for energy we need food.So if we eat a banana and then ride a kilometer and a half our footprint is 65g of CO 2 .However if we eat bacon before the bike ride it's 200g.In fact bananas are good in general because they don't need packaging they can be transported by boat and they grow in natural sunlight.
So does this mean that cycling is bad for the environment? Absolutely not for a start if you cycle you don't use your car and the fewer cars on the road the fewer traffic jams.And cars in traffic jams produce three times more CO 2 than cars traveling at speed.Cycling also makes you healthy and less likely to go to a hospital.And hospitals have very big carbon footprints!
So maybe it's time for us all to start making some changes.Pass me a banana and a pint of local beer please.