"We know that people buy socks, toilet paper, and cat litter, and they can either buy the crappy corporate stuff or the good, green, socially-responsible stuff. That's the choice," he said.
But Ahmadi sees a flaw in this premise. As long as progress is measured and defined by economic growth the neverending requirement of the capitalist system society will continue to fall short of sustainability targets, no matter what kind of products people buy, he said.
"At some point there is a threshold, even for green products, when the net benefits of producing the product will be surpassed," he said. "We need to go back to the framework that the economy is currently based on. At the moment, perpetual growth is the only way to assign value. But this linear way of thinking is dangerous to the sustainability of the planet. We must define value differently."
More than 125 speakers attended the event, including Democracy Now! founder Amy Goodman, nutrition expert Marion Nestle, and Mayor Gavin Newsom. Some even emphasized the tension inherent in staging the festival.
"It's a good thing and a bad thing. People leave more conscious and aware, but they also leave a tremendous footprint getting here and leaving," said CEO of Gather restaurant Ari Derfel, who spoke on the main stage in front of a piece of art made from a year's worth of his own trash. "People do engage in gross consumerist behavior. But they also get engaged with some companies that are doing incredible things."
Although he added that a green future must go beyond that represented at the Green Festival, he acknowledged that it represents the period of transition we now live in. "We can't go from A to Z without touching on all the letters in between. And we are still in a consumer-based, material goods economy. We couldn't make one wholesale swoop in one day."
Yet for Derrick Jensen, environmental activist and author of Endgame a book that questions the inherently unsustainable nature of modern civilization events like the Green Festival don't really address the real problems at the center of the sustainability movement.
"I don't see it as a transition," said Jensen, who made a speech at the event a few years ago. "It is not nearly sufficient. Now there is an attempt to add the word "green" before something and pretend that we're actually going to make a significant difference. But this is problematic."
The problem, as he sees it, is that attendees simply learn to accept the existing economic system and even believe it can become sustainable. They come to think that buying the right socks or toilet paper is helping to save the planet.
"Where is the overtly revolutionary material?" Jensen asked. "Where is the acknowledgement that capitalism needs to come down, or the discussion of the psychopathology of those in power? They talk only of alternative economies, but look what happened to every alternative economy they get taken over and consumed by mainstream culture."
Jensen added that the notion of basing a revolution on changes to personal consumption is not only inherently flawed but dangerously misinformed. "This sort of festival is based on the mistaken notion that personal consumption represents a significant portion of the economy," he said. "In reality, 1,600 pounds of trash are produced per capita. If I reduce that to zero, it's great. But per capita waste production by industries is on average 26 tons. That is 97 percent of all waste.
"This festival can make you feel good for one day, but then you just go back to normal life," he added. "And in some ways, it's a real distraction.