Carbon Footprints. Everything You Need To Know
What Is A Carbon Footprint?
A carbon footprint is the amount (in grams) of carbon dioxide (CO₂) emitted in the manufacture, storage, use and disposal of a service or object.
So the carbon footprint of flying to Paris includes the CO₂ from burning the aeroplane's fuel, AND from everything else involved in making the journey happen: manufacturing the plane; electricity for the airports; disposing of the leftover chicken from your airline meal. You name it, it has a carbon footprint
Why Is Carbon (Di-Oxide) A Problem?
CO₂ is one of several gases which are naturally present in our atmosphere and which trap some of the heat from the sun close to the earth's surface. By doing this they act like a blanket for the earth which is essential to keep Earth warm enough for life - without this Earth's average temperature would be a very chilly -18'C.
This process is known as the Greenhouse Effect. It is Good.
BUT as we add more gases to the atmosphere (for example by burning fossil fuels for energy and farming) more heat is being trapped and Earth is getting hotter and hotter. In other words the process is being ENHANCED.
This is known as Global Warming. It is Bad.
Natural vs Enhanced (by man) Greenhouse Effect
OK That Makes Sense. But Why Carbon Footprinting?
It measures the amount of CO₂ and other greenhouse gases* we each emit, showing us our personal contribution to global warming. It also allows us to measure what things give off the most gases, and helps us set targets for reducing our emissions.
On average, globally, we each emit about 7 tonnes CO₂e per year.
To keep global warming to a maximum of a 1.5'C increase we need to reduce that to 3 tonnes CO₂e per person per year. 7 to 3? Sounds easy right? Think again...
The average of 7 tonnes includes all those people in the developing world who use very little energy. In the developed world we use huge amounts: 15 tonnes per person in the UK, and up to 30 tonnes in America and Australia.
And as the developing world gets more developed, using more and more energy, global averages will increase well beyond the ideal of 3 tonnes, leading to a dangerous acceleration of global warming.
Uh Oh. What Can We Do?
In his book How Bad Are Bananas - The Carbon Footprint of Everything, Mike Berners-Lee advocates that we should aim to reduce our footprints to 10 tonnes CO₂e per year. Whilst this is only a modest step along the way to the optimal 3 tonnes, and if the developing world also set 10 tonnes as their target, the result would be disastrous, it is an achievable and realistic starting point (as long as a 3-tonne lifestyle remains a longer term target).
A year's worth of 10-tonne living means limiting ourselves to around 27.4 kg CO₂e per day. The table below show what this could look like.
If you would like to find out more about how you can reduce your footprint see our Guide to Reducing Your Carbon Footprint For Good, coming soon.
*Carbon Footprint is measured in grams of CO₂e not just of CO₂. The 'e' refers to the volume of Carbon Dioxide and equivalent gases and is shorthand for all gases which may be emitted and contribute to the enhanced greenhouse effect (global warming). It is necessary because CO₂ is not the only, nor even the most potent of the gases emitted which contribute to enhanced greenhouse effect. Methane, Nitrous Oxide and even H₂O all play their part. However as CO₂ represents 86% of all greenhouse gases, it is used to represent the others, in order to avoid the complex and lengthy process of writing out the volume of each gas emitted by each process.
Sources: Mike Berners-Lee; Our World: United Nations University; edie.net