Now in its ninth year, Earth Hour's goal is not to achieve measurable electricity savings, but to raise awareness of the need for sustainable energy use. But how much of an impact do the activities in our daily lives really make?
The carbon footprint of some common activities:
Email and internet
Even a short email is estimated to have a footprint of 4g of CO2e (gCO2e) - including greenhouse gases produced in running the computer, server and routers and a part of their manufacture.
An email with a large attachment emits about 50gCO2e, and a spam message, not even opened by the recipient, is responsible for 0.3gCO2e.
The annual global footprint of spam is equivalent to 3.1 million passenger cars on the road using 7.6 billion litres of petrol.
A web search on an energy-efficient laptop leaves a footprint of 0.2gCO2e, and on an old desktop computer some 4.5gCO2e.
A mobile phone SMS costs about 0.014gCO2e.
Shopping
A plastic carrier bag leaves a footprint of 10gCO2e, and a paper bag 40gCO2e.
Drinking
A pint (473ml) of water from the tap generates 0.14gCO2e compared to 160gCO2e for a 500ml store-bought bottle.
A large cappuccino comes at 235gCO2e, compared to 21gCO2e for a cup of black coffee or tea for which just enough water was boiled.
Leisure
An hour of TV watching on a 38cm LCD screen yields 34gCO2e, compared to 88gCO2e on an 81cm LCD screen and 220gCO2e on a 61cm plasma screen.
1.6km of cycling powered by a meal of bananas would be responsible for 65gCO2e, compared to 260gCO2e for a mile powered by cheeseburgers.
- Total global emissions in 2010 were estimated at 49 gigatonnes (Gt or billion tonnes) of CO2 equivalent (CO2e).
- Sources: How Bad Are Bananas by Mike Berners-Lee; Fifth Assessment Report of the UN's Intergovernmental Panel on Climate Change; McAfee's Carbon Footprint of Spam study.
AFP
source: newshub archive
