Christian Aid Week will celebrate its 50th Birthday this year, 13-19 May, as Britain's longest running door-to-door fundraising week.

The golden jubilee event will kick off by encouraging people of all ages to 'go green' by planting trees in support of the charity's overseas work on climate change projects.

The first Christian Aid Week, in 1957, mobilised residents in 200 towns and villages across Britain, collecting £26,000 for overseas development work. Half a century later Christian Aid hopes to raise £15.5 million from the annual fundraising week.

Christian Aid operates in 700 local organisations across 50 developing countries. Working with poor communities, it trains people to deal with the effects of climate change and prepares them for the threat of natural disasters.

These local organisations also work on HIV, training and education, health and sanitation and peace and reconciliation.

"The world has changed significantly in the past 50 years,'" said Daleep Mukarji, director of Christian Aid.

"Little did we know in 1957 we would be facing the problem of climate change which is already destroying the lives of thousands of vulnerable people across the world.

'"Christian Aid Week remains a vital part of our annual fundraising efforts and as we face new challenges, and our work increases, so too does our reliance on the generosity of the public. Without the incredible support of individuals and churches across the UK and Ireland Christian Aid would not have become the organisation it is today."

This year Christian Aid is encouraging people to plant trees in their gardens, community spaces and churchyards as a way of reflecting on the impact deforestation and climate change is having on poor communities around the world.

Diarmuid Gavin, award-winning garden designer and star of the BBC's hit TV show Home Front, said: '"I travelled to Kenya with Christian Aid last year and saw the devastating impact climate change is having on small-scale farmers who rely on the land.

"Drought is a serious issue there and it's inspiring to see how Christian Aid partners are teaching some of the world's poorest people new agricultural techniques to enable them to make the best use of the little water they have to grow food.

"We plant trees for ornamental reasons, because they look nice in our garden. However in developing countries, such as Kenya, that have been heavily deforested, they take on much greater significance. Trees not only encourage the rains but help prevent soil erosion that can lead to fatal mudslides."