Introduction

Whole Systems Approach to Ecological Design

Appropriate Technology: Water

Organic Agriculture and Local Food

Appropriate Technology: Energy

Green Building & Retrofitting

Carbon Footprints

A carbon footprint is a measure of the impact our activities have on the environment, and in particular climate change. It relates to the amount of greenhouse gases produced in our day-to-day lives through burning fossil fuels for electricity, heating and transportation, etc.  Our carbon footprint is a measurement of all greenhouse gases we individually produce and typically is in units of tonnes of carbon dioxide equivalent per annum (tCO2pa).

The pie chart aside shows the main elements, which make up the total of a typical person's carbon footprint in the developed world.

A carbon footprint is made up of the sum of two parts, the primary footprint (shown by the green slices of the pie chart) and the secondary footprint (shown as the yellow slices).

1. The primary footprint is a measure of our direct emissions of CO2 from the burning of fossil fuels including domestic energy consumption and transportation (e.g. car and plane). We have direct control of these.
2. The secondary footprint is a measure of the indirect CO2 emissions from the whole lifecycle of products we use - those associated with their manufacture and eventual breakdown.

A Few Facts:

• At start of Industrial Revolution the CO2 concentration in the atmosphere was 280 ppm
• By the late 1950s the CO2 concentration had risen to 315 ppm
• It is now 380 ppm
• And it is rising by 2 ppm annually
• The scientific evidence now states that it needs to be reduced to 350 from 380. We are already too high
• Carbon footprints vary by large amounts between nations.  In the USA it is ~20 tCO2pp/pa (20 CO2 tonnes per person and per annum), while the UK’s carbon footprint is 10.62 tCO2pp/annum and some African countries have footprints of <0.5 tCO2pp/pa.

It is important to measure the footprint either as a consumption number or from production within a country or bioregion or community.  Mixing the two methods can lead to double counting or omissions.

The chart to the side is for 2000.  The footprints for China and India are now rising rapidly.

• Carbon cycle
• Climate change
• Carbon footprint
• Carbon emissions reduction
• Effects of climate change
• Peak Oil

Main elements in the carbon footprint
Click on the image to enlarge

It's now established that when particulate material (e.g. soot and carbon products), generated from vehicle exhausts, aircraft and industry, enters the atmosphere, then less light reaches the ground - this is known as 'Global Dimming'
Source: Carbon Footprint

Carbon footprints in tonnes of CO2 per capita per annum from 0 to 94 tCO2pp/pa
Click on image to enlarge