If 100,000 people travel to Edinburgh for the summit, they will be collectively responsible for emitting something in the order of 2,000 extra tonnes of CO2 into the atmosphere. That's in just a few days. To put this in context, it would take one Sudanese person 8,000 years to produce the same effect.
Anyone taking a plane from London will rack up nearly 100kg of CO2 emissions each way, while those making the same journey by car will emit about 12kg each. This pales in comparison to the damage done by George W Bush as he flies from Washington to Edinburgh and back: he alone will be responsible for churning out two tonnes of CO2.
On the evidence of Glastonbury, the Edinburgh crowd will drink, wash and flush a million gallons of water. The city council is laying on 1,750 portable loos. Things are not always so simple: when a hundred families in Namibia received donor-funded flush toilets, most of them reverted to buckets within weeks because they couldn't afford the water to flush them.
Again judging by Glastonbury, the protesters are likely to generate roughly 60 tonnes of plastic waste in the form of food and drink containers and packaging. As no recycling facilities are planned, this will all go into landfill sites.