Religious pilgrimage is an important component of all religions. Pilgrimage sites are usually chosen in some part due to their natural beauty, and this (in addition to biodiversity and wildlife) stands to be damaged by large pilgrimages as well. The largest human gathering in recorded history was the 2001 Maha Kumbh Mela — a festival held every 144 years in Allahabad, India — which attracted more than 60 million Hindus. The confluence of so many people in one spot can mean a dramatic environmental impact. Religious sites are now feeling the strain on their resources and infrastructure, particularly when it comes to energy, water use, sanitation and waste.

Green pilgrimage is combination of all actions that strive to initiate changes in religious pilgrimage behavior and reduce climate change impacts with due emphasis on the belief that humans have a responsibility to protect our planet. This includes developing sustainable solutions for pilgrim cities for greening waste, sanitation, buildings, transport, food and accommodation and strategies to make the hosting of large scale pilgrimage more sustainable and environmentally friendly.