Here's a juicy story for you: PepsiCo has measured the carbon footprint of its Tropicana brand Pure Premium Orange Juice. Working with the Columbia Earth Institute, the company performed a comprehensive cradle-to-grave life-cycle analysis of the product and discovered that each 64-ounce container produces generates about 3.7 pounds of carbon. The finding was certified by the U.K.'s Carbon Trust using the recently-launched PAS 2050 standard for assessing greenhouse gas emissions. It's the first North American-branded product to receive this independent certification.

It's an important step on a number of levels. For one thing, carbon is something of a johnny-come-lately to the world of life-cycle analysis, for one simple reason: climate change is a relatively late bloomer in the garden of eco-anxieties. PepsiCo's move shines a spotlight on how important it is for companies to measure their products' carbon footprint using third-party certifiers.

Second, it helps legitimize the PAS 2050 standard, which was co-sponsored by the Carbon Trust and the U.K.'s Department for Environment, Food and Rural Affairs (Defra), and published by the eminent BSI Group (formerly the British Standards Institute). Companies need respected third-party certification to be credible. This is what the PAS 2050 standard provides, not in spades so much as with a side order of tea and crumpets.

It's also a launching pad for a broader Pepsi initiative, which intends to measure the carbon footprint of other products as part of the company's commitment to reduce its CO2 load.

A Pepsi spokesperson emphasized the extent to which the life-cycle analysis was educational. "We wanted to learn about where we were producing carbon along the entire life cycle. This will enable us to develop effective strategies for reducing our carbon footprint." PepsiCo's move serves as a reminder that with carbon as with everything else, you manage as well as you measure.

It's a new, carbon-sensitive world we're living in. With this announcement, PepsiCo is showing the way.