When the worldwide Live Earth concerts took place on July 7 this year, critics claimed that the concerts would actually do more harm than good due to their environmental impact, and now, four months on, the extent of that impact has now been revealed with the competition of the Live Earth environmental audit.

The study shows that the concerts emitted nearly 20,000 metric tons of carbon and that 97 metric tons of waste was collected, however, 81% of the waste was recycled or composted, and the carbon emissions were kept to within target levels.

Methods used to keep the carbon footprint down included choosing to host the concerts during daylight hours, using LED lighting, donating banners for reuse (in South Africa, banners went to a rural township to make sunshades for school playgrounds); using biodegradable plastics at concessions stands and using alternative-fuel buses and fuel-efficient cars.

The greatest area of carbon emissions was audience travel, generated by almost one million people who attended the concerts in person. Many of the attendees nonetheless heeded the shows message. In Shanghai and Tokyo, more than three quarters of the audience rode public transportation, but in New York less than a quarter of attendees rode trains and buses to the venue.

The main aim of this environmental report is not to silence the critics, however, but to set a benchmark for the sustainable event industry and show the music industry how the environmental impact of concerts and festivals can be reduced.

As Live Earth organizer Kevin Wall explains: “Some say we could have done more with less, that our method was antithetical to our message. Frankly, you can only reach so many people standing around a campfire singing 'Kumba Ya. Our goal was to educate and inspire billions of people worldwide to take action, and while that effort generated carbon emissions on one day, those impacted by this event have been motivated to reduce their energy use every day.

"From the start we were committed to making the concerts themselves low-impact events and to achieving a high level of transparency in conducting a broad report. We hope that we've not only set the bar high for ourselves, but have set a new watermark in sustainable event production for the industry at large."