Yesterday was a key date for the residents of Birmingham after a leading environmental charity calculated that the date was when the city has already consumed its fair share of the Earth's resources for the entire year.

The experts at WWF-UK believe that this means that for the rest of 2008, residents will be contributing to an unsustainable global debt that is having major impacts on the planet.

Colin Butfield, head of campaigns at WWF-UK, said: "If everyone in the world consumed resources at the same rate as the people of Birmingham, we would need nearly three planets to sustain us.

"Current lifestyles in the UK are depleting the Earth's natural resources quicker than it can replace them and driving rapid changes in the world including climate change, deforestation and the near extinction of many species.

"Birmingham has already witnessed extreme weather events such as the tornado which struck parts of the city in July 2005 and such events are likely to become more frequent as a result of climate change."

There are steps that can be taken to help reduce an individual's impact on the planet - MPs Clare Short and Lynne Jones are among the charity's supporters who are taking the advice.

By calculating their carbon footprint at wwf.org.uk/calculator and using the eco-tips provided they can then devise a personal plan to reduce it.

Clare Short MP said: "Our present way of life, based on greedy materialism, isn't making us happy. We need to change and WWF's suggestions will help."

Colin said: "May 5 highlights the need for us all to reduce our consumption of resources and move from a three-planet to a two-planet lifestyle. The challenge is not just about consumers though - government and business must also play their part."

WWF's One Planet Future campaign report, Ecological Footprint of British City Residents, included calculations about the average ecological footprint of cities' residents. An individual's ecological footprint relates to the land and sea area required to provide food, resources and energy, as well as absorb waste and pollution. The main factors affecting this are housing, food, consumer goods, public and private services and transport.

Birmingham ranks 17th overall out of 60 UK cities but its housing footprint ranked them much lower at 35th position. Other cities also going into eco-debt on the same day include Bradford and Lincoln. In the UK, Winchester uses the most resources while Plymouth and Newport in Wales use the least.

Colin said: "We are likely to experience more extreme weather events such as heat-waves and flooding, increased food prices, caused by flood damaged crops and higher costs of running our homes - domestic energy use on household products has doubled in the last 30 years.

"Native species including hedgehogs are also under threat due to warmer winters and reduced availability of their food supply and many of our trees will also be affected by the changing climate and competition between different species."