Two of the Church of England's most senior Bishops are today urging people to cut their carbon rather than give up chocolate this Lent.

The Bishop of Liverpool and Vice President of Tearfund, the Rt Rev James Jones, and the Bishop of London, Dr Richard Chartres, are joining with development agency Tearfund in calling for a cut in personal carbon use for each of the 40 days of Lent, which begins tomorrow.

At the same time a Tearfund survey reveals that three out of five adults in the UK are willing to take an energy saving action this Lent.

Tearfund and the bishops have launched the fast because of the urgent need to reduce carbon emissions, and to protect poor communities around the world who are already suffering from the ravages of climate change.

Bishop Jones said: "Traditionally people have given up things for Lent. This year we are inviting people to join us in a Carbon Fast. It is the poor who are already suffering the effects of climate change. To carry on regardless of their plight is to fly in the face of Christian teaching.

"The tragedy is that those with the power to do something about it are least affected, whilst those who are most affected are powerless to bring about change. There's a moral imperative on those of us who emit more than our fair share of carbon to rein in our consumption."

The Carbon Fast is a forty-day journey through Lent, towards a lighter carbon footprint, with a simple energy saving action per day. Actions include snubbing plastic bags, giving the dishwasher a day off, insulating the hot water tank, and checking the house for drafts with a ribbon and buying draught excluders

Participants are asked to begin the Carbon Fast by removing one light bulb from a prominent place in the home and live without it for 40 days as a constant visual reminder during Lent of the need to cut energy. On the final day of the Fast, people are encouraged to replace the missing bulb with an energy-saving bulb. Over its lifetime that one bulb will save 60kg of carbon dioxide per year and up to £60.

Dr Chartres said: "We all have a pivotal role to play in tackling the stark reality of climate change. A whole host of scientific studies have made clear that it is no longer possible to find excuses for doing nothing. Nor it is not enough to point the finger of blame at others and to demand that somebody should act for us.

"Now is the time for individual and collective action in addressing the unsustainable way in which we are exploiting the earth's resources. Together we have a responsibility to God, to future generations and to our own wellbeing on this earth to take action."

An estimated 9.5 tons of carbon dioxide are emitted per person per year in the UK. In Ethiopia the average is 0.067 tons and in Bangladesh 0.24. According to research, the earth can sustain 0.8 per person.

Tearfund is mobilising families, churches and individuals to action on this vital issue, and many church leaders and scientists have thrown their support behind the Carbon Fast, including Joel Edwards, General Director of Evangelical Alliance UK, Dr Rowan Williams, the Archbishop of Canterbury, Roger Forster, Senior Leader of the Ichthus Christian Fellowship, and Sir John Houghton, Co-chair of the Scientific Assessment Working Group of the Intergovernmental Panel on Climate Change between 1988 and 2002.

Sir Houghton, also former chief executive of the MET, advises Tearfund on climate change. He said: "The scientific debate about the basic issue of climate change is over. Climate change is real. Evidence for it is to be seen in every corner of the globe.

"Tearfund have sounded an urgent warning that climate change is already hitting places like Bangladesh, Ethiopia and Niger hard. Climate change shows us that our energy-hungry lifestyles are harming our poorer neighbours across the world, now.

"The moral imperative for us to act is unquestionable and inescapable."

Tearfund is helping communities cope with the impacts of climate change right around the globe. Tadesse Dadi, a Tearfund worker in Ethiopia said millions are already being affected: "Climate change may not yet be a problem for people in Europe, but here in Ethiopia its effects are being felt today by millions of ordinary men and women farmers. These poor communities, who have contributed least to climate change, are suffering the most from its effects."

For a copy of Tearfund's Carbon Fast click on www.tearfund.org