Ecological footprinting has been around for half a decade or more and is growing in popularity. It calculates the area of land required to maintain current resource and energy consumption. It has been applied at local and national level in the US, the Netherlands, Scandinavia and Mexico, and some recent studies have derived footprints for products, processes and companies.
The Isle of Wight project is one of 25 mass balance studies funded by Biffaward which are looking at resource use and waste generation across different sectors, material streams and community groups. The project was first mooted in 1998, but was delayed because Entrust - the body which regulates landfill tax funding - could not see the link between materials flow analysis and waste minimisation.
The final report was published in November. It was carried out by ecological footprinting specialists Best Foot Forward, the Isle of Wight Council and Imperial College.
The study found that the Isle of Wight has a footprint of 648,808 hectares - more than double its actual area. This equates to a per capita footprint of 4.47ha, slightly lower than that of the UK as a whole, but around double the global average of 2.2ha. Previous studies have put the available global productive area at 1.9 ha per capita.
The study collected data on the volume and nature of the island's material and energy flows. It found that the island consumed 753,000 tonnes of materials in 1998/99 - or around 5.3 tonnes per head. Some 170,000 of this ended up as waste, while the remainder either remained on the island as "stock" - for example as buildings - or left as gaseous or liquid emissions.
The island used around 624GWh of energy over the year - 13GWh of which came from its refuse-derived fuel plant. It also consumed around 11,700Ml of water.
These figures were used to calculate the island's ecological footprint. The materials were split into different categories, including ferrous metals, non-ferrous metals, timber, glass, plastics and food, which were themselves subdivided. Different factors were applied to each category to convert the material quantities into hectares.
The process takes into account the amount of land required to supply the materials; the land degraded in the process of extraction, transportation and manufacturing; and the embodied energy in materials. Additional factors were applied for waste - recycling and waste-to-energy has a smaller footprint than landfill - and energy.
The energy factors take into account the land used and degraded to generate electricity along with the amount of land required to act as a sink for carbon dioxide emissions.
The strength of footprinting, said Nicky Chambers of Best Foot Forward, is that it allows comparison within and between sectors and areas and is a good tool to explain sustainability.
"It is applicable at all levels, from the micro level of products and lifestyles, up to the macro global level, and the corporate and national levels in between," she said. "It truly makes the link between thinking globally and acting locally."
The study highlighted options ranging from waste minimisation, energy efficiency and switching to renewable energy for reducing the island's footprint. It also identified areas of significant impact.
The island has a relatively good record on recovering domestic waste - around 43% is diverted from landfill by recycling, composting and energy recovery. But the picture for the commercial sector, which generates 64% of the island's waste, is not so rosy. All but 3% of commercial waste goes to landfill.
The research also uncovered some bizarre situations such as island-grown produce like tomatoes and milk being exported to the mainland for packaging before coming back. The additional transport and packaging increases the island's footprint by more than 300ha.
Best Foot Forward is talking to three or four other councils about measuring their footprints and has worked on a project for the Association of Certified Chartered Accountants on using the approach as a business indicator. A number of firms, including Anglian Water, are already using the approach and the European Commission has commissioned a review of the technique.