a world map of ecological and human sustainability

Researchers create new calculation models for a more evidence-based debate about sustainability

Clear indicators and evaluation criteria are essential to save the environment. Two Sweden-based researchers hence introduce a new indicator, eco-balance, and a new criterion that takes into account both human and environmental sustainability. The conclusion is that many countries need to reconsider their consumption as well as their population in order to be sustainable.

When we discuss the environmental issues that are becoming more and more noticeable, the debate easily turns black and white. Overconsumption versus overpopulation; developed versus developing countries; North versus South. However, the reality is as gray in different shades as the smoke that rises from forests that are on fire and the water that floods fields and cities.

• Ecological footprint: A measure of how much area of biologically productive land and water an individual, population or activity requires to produce all the resources it consumes and to absorb the waste it generates, using prevailing technology and resource management practices.
• Biocapacity: The capacity of ecosystems to regenerate what people demand from those surfaces. Life, including human life, competes for space. The biocapacity of a particular surface represents its ability to regenerate what people demand. Biocapacity is therefore the ecosystems’ capacity to produce biological materials used by people and to absorb waste material generated by humans, under current management schemes and extraction technologies.
(Source: footprintnetwork.org)

Giangiacomo Bravo, professor of sociology at Linnaeus University in Sweden, and Lucia Tamburino, researcher at IGDORE, therefore present a new criterion for sustainability in the journal Ecological Indicators. This more comprehensive criterion takes into account both the human and the environmental dimensions.

“The criterion consists of two parts: ecological and human sustainability. Ecological sustainability is estimated using a new indicator, the eco-balance, which is based on the proven concept of ecological footprint. Human sustainability is based on the estimated level of biological capacity that each person needs to consume to achieve an acceptable level of human development”, says Giangiacomo Bravo.

Both expected and surprising results

• The researchers first introduce a new concept: population biodensity (PB). PB is the ratio between population and biocapacity for a given area, e.g. a country. In contrast to population density, population biodensity thus takes into account the area's biological productivity.
• The new measure eco-balance (EB) is then defined according to the formula EB = 1 – PB•EF, where EF is the ecological footprint per inhabitant. To be environmentally sustainable, an area must have a value of EB greater than or equal to 0. A positive EB means that the impact of the people in the area is less than the local biological capacity. A negative EB means that people in the area instead use more biocapacity than is available.
• Suriname has the highest EB in the researchers' calculations, which included countries with an area of at least 10,000 square kilometers, with 0.97. Israel had the lowest with -24.45. The world as a whole had an EB of -0.73, which shows that our planet is not ecologically sustainable as a whole.
• The comprehensive criterion for sustainability, called EH, then divides the countries of the world into four groups. 24 countries meet both the ecological and the human sustainability conditions, 23 only the ecological one, 55 only the human one, and 51 neither condition.

The researchers' calculations show that the world as a whole does not meet the new criterion. To a large extent, the results were expected – only 24 countries meet both requirements. One of these is Sweden, even if its eco-balance has declined over the years because of the country's population increase.

Even a small individual footprint can have significant consequences in a populous country. An important question is therefore whether changes in consumption patterns and technological improvements can reduce the environmental impact without reducing human well-being and development too much, or whether the population factor must also be taken into account. The latter is the conclusion drawn in the article.

“We were suprised that not only densely populated, poorer countries but also several highly developed countries should reduce their population, along with their consumption, to reach sustainability”, says Giangiacomo Bravo.

Another surprising result is that if you follow the paths towards sustainability identified in the paper, it would lead to a much more equitable world, the researchers say. Equality would emerge as a result, not a driver, of sustainability.

A contribution to a more evidence-based debate

“Our article's main message is that there are no independent, sustainable levels of technology or individual consumption, but only sustainable combinations of technology, consumption, population and available biocapacity.”

“Our goal has been to contribute to a more evidence-based debate on sustainability and how to reach it. The new indicators can help policy-makers get a more comprehensive picture of current challenges and realistic solutions”, Giangiacomo Bravo concludes.

More information

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IMAGE: World map with countries coloured according to the comprehensive EH criterion.
• E+H+ (green) are countries that satisfy both the ecological (E) and the human (H) sustainability condition.
• E+H− (yellow) satisfy E sustainability only.
• E−H+ (blue) satisfy H sustainability only.
• E−H− (purple) satisfy neither E nor H sustainability.