Once in a lifetime all Muslims who can afford it and are well enough should undertake the Harge, the pilgrimage to Mecca.

The Hodge cleanses your sins throughout a year. You go back cleansed from all sins. It's an experience you would love to go through over and over again if you can.

Millions of people go to Saudi Arabia every year for the hudge

and the smaller pilgrimage known as the Umera.

But climate change means that the conditions they find there are already challenging.

It was really hot, super crowded, so I definitely felt the crowd and obviously with the added amount of people it just felt a lot hotter.

Now the Saudi government is aiming to increase the annual number of pilgrims to 30 million by 2030.

So is environmental disaster looming?

The immediate impact is from aviation, so most people are flying into Saudi Arabia.

People get up planes and then they get onto buses and go to the heart and of course those buses are petrol field.

Surridge is an enormous problem.

A lot of that flows out into the Red Sea.

Welcome to the documentary from the BBC World Service.

I'm Zubeda Malik and this is Greening the Hudge.

Scientists warned that the Hodge alone which takes place over five or six days each year

produces over 1.8 million tons of greenhouse gases,

roughly as much as New York City churns out over a two-week period.

In this program I'll be asking what the Saudi authorities, campaigners, religious scholars,

and the pilgrims themselves can do to reduce that

enormous carbon footprint, and what's getting in the way of a greener

pilgrimage. Last year the image.

Last year the extreme temperatures faced by Harge pilgrims in the summer months made headlines,

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