Glastonbury - Eco-Festival?

Glastonbury has long presented itself as the greenest festival on offer and it was under this assumption that I made the trip down for a weekend of fun as well as learning.
Surely 160,000 people camping in fields would damage both the local environment and emit thousands of tons of carbon dioxide (and other gases) into the atmosphere? Or does the fact that these people have stopped using their homes, cars and most electrical appliances for a few days signal a notable drop in personal emissions? A closer look into the workings of the festival should give me an answer.
Accomodation - everyone (bar a few posh campers) sleeps in tents so no little need for lights or heaters. People do bring butane stoves and portable heaters but the warm weather renders these obselete.
Toilets - the ammonia and methane released into the atmosphere by the almost open communal toilets will precipitate a big rise in emissions from the festival goers. However, minimal toilet paper was used thus saving trees and decent toilets were available for the price of a small contribution to Water Aid, who provided the service.
Showers - all the shower units provided hot water that was from solar power (Solar Century provided this service) and therefore required no gas to be burnt. Also, the units were self contained meaning that the water used by purified and reused.
Electricity - I found out that the generators were run on biodiesel and not the sort that uses crops which could be food but the sort that is made from leftover oils and plants.
Food and drink - I was impressed by the range of vegetarian food on offer as this is the most ecological way to eat, and I was equally surprised by the popularity of these food stands. Even the stands which did serve meat also had a good range of vegetarian options. However, on meeting my fellow campers I found the highest percentage of veggies to carnies outside of posh London wholefoods shops which was unsurprising given the nature of Glastonbury. As for the drinks, they were all served in biodegradable cups and the ciders and ales were all locally produced and much of the wine was fair trade. There were still the usual options but also lots of organic drinks were available.
Transport - many people did choose to drive but the number of buses going on the road was huge, even casuing a large traffic jam as I left on monday morning. The people I did ask about driving said that they were offering lifts to people and had cars full of people and equipment. So, not exactly one person per car.
Recycling - this was a big issue given the amount of rubbish that was generated. Glastonbury had three recycling bins available and these were places all around the site. One was for plastics, one for food waste (including the cups and plates) and one for all other waste. Most items would have gone into the first two but such was the extent of it that these bins constantly overflowed and due to the difficluty fo moving trucks through the crowd they were only emptied when people went to sleep. The issue of littering was a major one and the cleanup at some of the main stages would need several days to be complete. I hope that all the rubbish pressed into the mud would have ended up in the recycling bins.
The festival was both a great success and a green success both in its message and in its mechanisms. My only conern was that this might be a case of preaching to the converted.