Carbon footprint is man's quantifiable mark on the planet's ecosystem in terms of greenhouse gas (GHG) emitted to the earth's atmosphere. The types of GHGs have been qualified by carbon reduction governing bodies such as the Kyoto Protocol and the Montreal Protocol in the case of Hydrochlorofloruocarbons (HCFCs).
They are deemed harmful to the environment and add up to global warming. Carbon footprints are measured in terms of these GHG emissions; as quantifiable units to determine the sustainability of mankind's expansion on the planet.
• Carbon footprint as man's “Ecological Footprint”
Carbon footprint came into life with the release of the first academic publication on ecological footprint by William Reese in 1992. It argues that “prevailing economic assumptions regarding urbanization and sustainability of cities must be revised in light of global ecological changes”.
The concept was originally called “appropriated carrying capacity” which was eventually termed “ecological footprint” to improve its mainstream appeal. William Rees and Mathis Wakernagel (co-author) eventually published their studies in the book, “Our Ecological Footprint: Reducing Human Impact on the Earth” which became the founding principle behind what is now known as carbon footprint.
• Qualification of greenhouse gasses and carbon dioxide equivalent (CO2e)
The US Energy Information Administration (EIA) reports that there are six greenhouse gases emitted in the United States and these are: Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O) and Industrial Gases: Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs) and Sulfur hexafluoride (SF6)
These same types of GHGs are also targeted by large governing bodies such as the Kyoto Protocol; and CO2e (for carbon offsets) certifying bodies such as the VCS, CDM and the Gold Standards.
There are other GHGs which are mainly naturally occurring and not included in this list. The GHGs included in this list are categorized as largely influenced by man's expansions and those which are exclusively man-made.
• Sources of greenhouse gas emissions
Carbon footprint is measured terms of pounds, kilograms or metric tons of greenhouse gas (GHG) emissions. There are many types of greenhouse gasses from different chemical compounds found on the earth's atmosphere.
Some of these GHGs are naturally occurring. Some are produced through man's activity while others are exclusive generated by man as a product of his expansion through industrialization.
Water vapor and ozone are greenhouse gasses but they are to a large extent, naturally occurring. CO2 is also partly naturally occurring, but its level has risen considerably since pre-industrial levels; by around 100 ppm. This is mainly due to CO2 produced from fossil fuel combustion and deforestation.
Methane is considered to be more potent than CO2 in terms of its effects on global warming. It has risen by over 1000 ppb since pre-industrial levels. This is mainly due to expansions in the agricultural sector; from livestock and agricultural waste management.
Another important contributor to increasing methane levels in the atmosphere is the growing number of landfills from man's waste.
Nitrous oxide level in the environment has also slightly risen as a result of agricultural expansion involving inorganic fertilizer use. The last three remaining greenhouse gasses are man-made. These gasses are also called halocarbons resulting from industrialization.
The US Environmental Protection Agency (EPA) has also ranks home heating, home cooling, electricity consumption and transportation as the main sources of GHGs that the individual American contributes to the atmosphere.
• Life Cycle Assessment (LCA) and Carbon Tracking as assessment and measurement tools for carbon footprint
There are two important assessment and measurement tools to analyze and quantify the amount of GHGs emitted to the atmosphere. These GHG emissions are produced in the manufacturing of products and coming from every type of human activity which register carbon footprint.
1.) Life Cycle Assessment (LCA) is the cradle-to-grave analysis of the environmental impact of products, processes and activities. LCA also evaluates the technologies supporting these processes - whether products, processes and services are ecobalance or not in their life cycles.
LCA is important to make informed decisions which also aids in quantifying GHG emissions as a component of carbon tracking.
2.) Carbon tracking is use to quantify the carbon footprint produced by individuals, organizations and countries. It is a tool to estimate/determine the GHGs produced by any entity and the carbon dioxide equivalent (CO2e) required to absorb or reduce carbon footprint.
Carbon tracking is also a vital component of carbon offsets and the whole cap-and-trade system of governing GHG emissions.