Answers to everyday questions like these can help WWF and local authorities in the UK find answers to bigger questions. What kind of mark are we leaving on the planet? How can we change to a more sustainable way of living and working in our homes, schools and offices? In short, how big is our "footprint" on the world around us - and how can we learn to tread more softly?

Measuring and reducing our ecological footprint - the impact each of us makes on the natural world and its resources - is the aim of a number of new WWF partnerships that could provide sustainable answers for local authorities throughout the UK.

But why is our footprint so important? Well, with more than six billion people living on the planet - and the number is increasing by 215,000 a day - there is a growing need for everyone to understand how much of the Earth's natural resources are available to share between us. Quite simply, if present trends go unchecked, humans will soon need the resources of three Earth-sized planets to sustain our consumption of energy, crops, meat, fish and wood. WWF's latest Living Planet Index, which tracks trends in populations of hundreds of species of mammals, birds, reptiles, amphibians and fish, estimates that by 2050, humans will over-consume the Earth's biological capacity to such an extent that human welfare will inevitably suffer.

The Ecological Footprint is one way of measuring how our lifestyles impact not only on the planet, but also on other people. It calculates how much productive land and sea is needed to feed us and provide all the energy, water and materials we use in our everyday lives. It also calculates the emissions generated from the oil, coal and gas we burn at ever-increasing rates, and it determines how much land is required to absorb our waste.

Fancy a beer?
Everything we do adds to the size of our footprint. Take, for example, the apparently benign pastime of enjoying a beer. Land is required not only to grow the barley, but also for processing and distributing operations, for housing the brewery's management and administration, and for the pub, bar or restaurant which sells the end product. Additional forest land is needed to absorb the CO₂ released from all the energy that's used during harvesting, processing and shipping the beer. Somewhere on the planet, land was mined to make the metal for the combine harvester and other machinery used in the production and distribution process.

So the footprint can be applied to any product, individual, household, school, business, city, region or country. Using it allows us to see who is over-consuming and taking more than their "fair share" of the Earth's resources - and, at the other end of the scale, who's not getting enough.

Where do we go from here?
WWF has recently gained funding of £520,000 from Biffaward, the landfill tax credit scheme operated by Biffa Waste Services and the Royal Society for Nature Conservation, for a new project called Ecological Budget UK. This will provide the means of enabling the countries and regions of the UK to make positive changes for sustainability, which in turn will reduce their ecological footprint. In addition, £300,000 has been donated by the Scottish Executive and other partners for a local project in Scotland.

In England, WWF is working on two detailed regional projects - one in the West Midlands, which will focus on regional policies, strategies and sustainable homes; and the other in the North-east/Sunderland, which will home in on community strategies and participation. In addition, we are developing a Footprint for every region of England, from Berwick to Penzance.

In Northern Ireland, WWF wants the ecological footprint to be regarded as an indicator of how successful government policies are for sustainable development. Northern Ireland has the biggest ecological footprint of any region in the UK, with energy use and waste production being the two biggest contributors. That's the evidence revealed by Northern Limits, a recent report on the use and disposal of natural resources in the province - and it's why WWF's footprint work is so important.

In Scotland, a partnership between WWF and local authorities in North Lanarkshire and the North-east (Aberdeen City and Aberdeenshire) will calculate the use of natural resources in their areas so that they can find ways of reducing pollution, waste and energy consumption. Scotland's Global Footprint report calculates that every year people in Scotland generate 15 million tonnes of waste and use enough energy to power 950 million television sets for a year. The project will also develop software to enable local authorities and schools to calculate their own footprint, and generate news stories to get the message across to the public.

In Wales, WWF is leading a project with 12 public, voluntary and academic partners to identify strategies for reducing our footprint. We are measuring the impact of two counties - Cardiff and Gwynedd - as well as Wales itself. The project brings together a range of partners including WWF, Cardiff and Gwynedd Councils, Cardiff and Bangor Universities, Stockholm Environment Institute (York), the National Assembly for Wales, and Assembly-sponsored public bodies such as the Environment Agency for Wales.

"It's now essential that we in the west adopt a lifestyle that strikes the right balance between using and protecting the environment," says WWF's Chief Executive, Robert Napier. "If we don't, the predictions are dire - which is why WWF is campaigning for everyone to tread lightly on the planet and develop a sustainable way of life."