With the growing global concern over climate change, footprints have become a popular concept. There has especially been increased emphasis on ecological, water and carbon footprints. These footprints provide nations with the information required to make the right decisions on resource management and sustainable development.
What is an Ecological Footprint (EF)?
First coined in 1992 by William Rees, the term ecological footprint refers to the pressure that human activities place on the earth’s ecosystems. It is a measure of the population’s demand of the planet’s natural resources.
Globally, this measure is used as an accounting tool, letting us know if the resources we need can be regenerated as fast as we are using them. An ecological footprint is usually measured in the form of global hectares (globally comparable, standardized hectares with world average productivity) and can be calculated for a person, a country or the entire planet.
In order to properly understand an ecological footprint, you will have to understand the term biocapacity. This refers to the capacity of the area to provide natural resources and absorb waste. For continuous sustainability, the ecological footprint should never be higher than the biocapacity.
In simpler terms, humanity’s demand for natural resources should never exceed the capacity of the earth to continuously provide natural resources and absorb waste. The lower the ecological footprint, the better it is for the planet. Some of the ways to achieve this include:
- Reducing the number of people per unit area
- Reducing consumption of resources per person
- Increasing resource efficiency
To calculate your personal ecological footprint, you can do this short quiz.
What is a Carbon Footprint?
The term carbon footprint first came into use in the early 2000’s and has steadily gained popularity since. This term refers to the measure of the total amount of greenhouse gases (CO2, CH4, HFC, PFC, SF6, N2O) emitted by human activities. It is usually measured in terms of kilograms of gas produced per unit time (usually a year).
A carbon footprint can be calculated for individuals, organizations, processes, products, and countries. Some of the strategies that can be used to reduce carbon footprint include:
- Using green eco-friendly products
- Using renewable sources of energy
- Advocating for the use of clean technology processes
- Practicing carbon offsetting programs
- Promoting the use of good waste management practices
It is worth noting that although the carbon footprint is viewed as an offspring of the ecological footprint, it was born in practice rather than in science. As such, there is no universally acceptable definition for this concept.
As such, the Kyoto Protocol has been used as a comprehensive way to quantify carbon print. This has allowed for calculations based on the various gases measured. This involves weighing of emissions per type of gas against their global warming potential before adding them up.
A carbon footprint has two parts; primary footprint and secondary footprint. While the former deals with direct emissions to the atmosphere, the latter one deals with indirect emissions. Direct emissions include gases produced from the burning of fossil fuels, burning of crops and factory chimneys.
On the other hand, indirect emissions include products or processes that lead to the emission of greenhouse gases (GHS). To calculate your own carbon footprint, you can use this free online calculator from Carbon Footprint Limited.
What is a Water Footprint?
Unlike the carbon footprint, the water footprint was born of science. Developed in the field of water resource management, it is a measure of the total consumption and contamination of freshwater resources and has definite universally acceptable calculation methods.
Like the carbon print, it is derived from the ecological footprint and is regarded as an environment pressure indicator. A water footprint is measured in the form of volume per unit time and can be calculated for individuals, communities, and organizations. It is worth mentioning that any water footprint has 3 important components. These include:
- Green water footprint; total volume of rainwater absorbed by the soil to form soil moisture
- Blue water footprint; total volume of surface of groundwater that has been evaporated for human consumption
- Grey water footprint; total volume of freshwater required to dilute pollutants in order to ensure that the water remains above the existing standards of water quality
Comparison between Water and Carbon Footprints
Due to some similarities between these two footprints, some treat them similarly. However, there are significant differences between them. Below is a table that provides a comprehensive comparison of these footprints.
|Carbon Footprint (CF)||Water Footprint (WF)|
|What is measured?||Total amount of carbon emissions||Total volume of water consumed and contaminated|
|Measurement units||Mass of carbon dioxide / CO2 equivalents per unit time or unit product||Water volume per unit time or unit of product|
|Components||CF per gas type: CO2, CH4, HFC, PFC, SF6, N2O||Blue, green and grey WF|
|Spatiotemporal dimension||Specific location and time don’t matter in the measurement of CF. Units are interchangeable||Specified by location and time. Units aren’t interchangeable|
|Calculation Methodology||· Bottom-up approach
· Top-down approach
· Hybrid approach
|· Bottom-up approach
· Top-down approach
Although environment pressure indicators such as ecological, carbon and water footprints manage to measure the human use of natural resources and the emission of pollutants, they can’t provide any information on how this affects the environment and as a result the human population.
However, they are still very important parameters, especially to policymakers in the environmental sector.