Ecological footprint (EF) is a measure of the demands that an individual or a group of persons make on global natural resources. In 1996, Wackernagel and Rees came up with the concept in a book called Our Ecological Footprint. It provides an overview of the complex concepts of the resources needed to sustain human lives in relation to the rate of resource replenishment, carrying capacity of the Earth and waste disposal, in simpler terms. Since then, the notion has gained popularity around the world and is now a common tool to measure the sustainability or unsustainability of common practices.
Basically, EF measures what is demanded of the Earth compared to what it can produce. The unit used is gha – global hectares (1 ha = 2.47 acres); EF can be used to measure individual, national, regional and global footprints. These values can then be compared to the average bio-capacity of the Earth to know if current practices are sustainable or not.
The EF actually measures the productive land required to produce renewable resources and to absorb the wastes produced. Productive areas are evaluated in terms of:
The EF value thus shows whether an individual or business or government is living sustainably with regards to the carrying capacity of their territory or living outside it. Thus, if they are drawing from the capital of other nations, they become ecological debtors.
EF values vary widely around the world; the larger the value, the less sustainable are the activities. For instance, based on 2014 data, Qatar topped the list with an EF of 15.5 gha/person compared to Haiti at 0.7 gha/person. The values reflect different lifestyles with overconsumption on one hand and poverty on the other hand.
People in Qatar enjoy an extravagant lifestyle and use a lot of energy for pumping water. In this way, they have a far greater impact on the Earth’s resources compared to people in poor regions who do not even have access to food and water. EF values for groups and countries also give an indication of what is going on and where unsustainable practices are being carried out. In Mauritius, for example,  the EF value was 4.5 gha/person in 2010. Although a tiny island, the value is enormous and is mainly attributed to mass tourism and touristic activities.
Globally, there has been an increase in resource demand since the 1970s. We have been using more than the Earth can produce and absorb through industrialization, urbanization and overexploitation of resources. Because of this, we are now in an ecological deficit, called ecological overshoot, which causes the Earth to take more time (instead of one year) to refill and get rid of wastes. Currently, our demand on Earth equals 1.7 Earths leading to more than 80% of countries being in ecological deficits.
You can easily calculate your ecological footprint by using calculators like the Global Footprint Network calculator amongst others. Principally, values regarding certain activities are entered into the calculator and then an estimate is given.
However, there are certain points in the concept that many people do not agree with:
Despite all the critics, ecological footprints are one of the best tools to give an apercu of an individual to global environmental impacts of our daily activities. The method is still being refined and in 2006, proper standards were established to use it. In 2008, a review by the European Commission acknowledged the limitations of the model but concluded that when used with other environmental indicators, the EF can be a good tool. Many businesses like Walmart and governments like the UAE have now embraced the concept and are using it as a measure to decrease their unsustainable practices.