Terracycle is allegedly the first startup with a negative ecological footprint. I seriously doubt it. I'm sure Craigslist has a lower footprint -- think of all the trees that haven't been chopped down, because it's so cheap to put an ad online instead.
But even Craigslist loses to Ford. Pre-Ford, most roads were knee-deep in horse effluvia. Now the worst we worry about is sever asthma and maybe apocalyptic global warming (which might have happened from horse methane, anyway).
Terracycle is impressive, but they're only the first company to achieve what they have if you use some really bad accounting.