Words by

Alex Elliott

You’d need to have pretty big feet to walk in our shoes. Our footprint is 25% bigger than the whole planet. However: it may be big, but it’s not clever.

The footprint in question is a metaphorical one: it is our ecological footprint. The tally of the renewable resources humanity takes from the planet against what the planet can regenerate. We have exceeded the planet’s annual sustainable bounty by some time in September each year.

Ecological footprinting is a theoretical science, but it is measured in the most tangible and physical sense possible: land area (usually given as gha, or ‘global hectares’). An ecological footprint analysis can be carried out for individuals, communities, nations and all of humanity, but also for things like factories, offices and even clubs and hobby groups. We can all find out our environmental impact in the form of a tangible gha number.

Notably, the ecological footprint does not include our use of non-renewable resources such as fossil fuels, metals and quarried goods – it is concerned solely with renewable resources. The Global Footprint Network sums it up thus: “how much land and water area does a human population require to produce the resources it consumes and to absorb its wastes under prevailing technology?”

1.9 gha per Person
Let’s put this into context. The amount of land needed to provide food, drink and all other renewable consumables – and to absorb the resultant waste – is 9.5 gha for every American. That figure is 5.45 for the British, 4 for the Swiss and just 1.5 for every Chinese person. At the present population level and with present technology, the planet can allow each human about 1.9 gha.

With increasing wealth and aspirations, the ecological footprint of the Chinese is growing rapidly – and so is the global population. But how are we able to live the way we do if there aren’t the resources available? After all, you can’t have what doesn’t exist.

The question is not just one of available resources, but more about the sustainability of those resources. We are still lucky enough to have the resources to live as wastefully as we want, but ecological footprinting aims to encourage us to leave enough for future generations. Deforestation, over fishing, species extinction and carbon-induced climate change are just some of the issues that underline our lack of sustainability.

Worryingly, the over-exploitation of natural resources can actually be an exponentially increasing problem – as taking a tonne of fish from a healthy stock will have less of an impact and be replaced quicker than taking a tonne of fish from a depleted stock. Just as there may not be ‘plenty more fish in the sea’, so too might we ‘not be able to see the trees for the (dead) wood’. The more we damage our tropical forests, the less able they are to regenerate.

Simplified Equation
Of course, measuring the impact of all human activity on all aspects of the natural world is incredibly difficult, if not impossible. A certain amount of simplification inevitably happens when turning Mother Nature into a mathematical equation, and as a result there are critics.

Figures based on crude estimates are often used and little notice is taken of geographical circumstances – as a hectare of intensive arable land may be given the same value whether in Iceland or in the middle of the Amazon. It is also difficult to account for multiple land uses, where a forest is considered a carbon sink and not a source of food and the food production and carbon absorption of residential areas are not considered.

Also, one person is considered to have a lower impact as a member of a family household of ten people than say one of three people. While true on a basic level, this fails to account for their possible contribution to over-population.

Does this hair splitting actually matter though? Supporters of ecological footprints think not. They argue that the figures are accurate enough to show that we are consuming far too much, far too quickly – and that’s all that matters.

Calculate Your Own Footprint
It is worth mentioning that ecological footprints are just one of several footprints available to the environmentally conscious – or to be forced upon the environmentally ignorant. For example, ecological footprints take account of climate change, because of the atmosphere’s status as a changing system and part of the carbon cycle – with carbon contributors and carbon sinks. It doesn’t take account of where the carbon is coming from though. For that you need a carbon footprint.

The carbon footprint is the amount of carbon emitted by each person, company, nation or other community through their use of fossil fuels. It is most commonly measured in tonnes per year.

You may also hear tell of such notions as bio-productivity footprints and biodiversity footprints. These are more accurate ways of looking at the impact of specific land usage and our impact upon the natural habitat in a given ecosystem.

And so ends ‘The Grapevine Lecture Series: Footprints 101’. We hope you find it useful. For more information, visit www.footprintnetwork.org.