Sleeping Bags: Zero Impact Challenge

5 manufacturers answer our call for eco-friendly sacks.

Let’s face it: Green materials are groovy in packs and water bottles, but sleeping bags? Now you’re messing with a dude’s beauty rest–and that warm fuzzy feeling you get from a tiny carbon footprint ain’t gonna last if your eco-sack sucks. Which is why we focused our second annual Zero Impact Challenge on bags. We wanted to learn whether top manufacturers could develop dependable three-season sacks with lower emissions. Along the way, we also hoped to discover whether down–as many believe–is a greener insulation than petroleum-derived synthetics.

Out of 30 companies invited, five rose to the challenge–Big Agnes, Feathered Friends, GoLite, Sierra Designs, and The North Face. The rules were simple: Send us a bag rated 20°F, plus an encyclopedia of data on materials, shipping, and energy use.

We sent the bags to testers in Colorado, Vermont, Kentucky, New York, and Utah for three months of evaluation. The scientific data went to Cooler, the firm that measured BACKPACKER’s carbon footprint and the packs in last year’s Zero Impact Challenge. Endorsed by three major environmental organizations, Cooler is a pioneer in climate studies and product analysis (learn more at

What We Discovered

The study yielded several key findings–and a few surprises. In the fabric realm, we learned that recycled polyester produces 35 percent less emissions than virgin poly, and 50 percent less than virgin nylon. And here’s a shocker: Goose down does not appear to beat recycled polyester. Many of us thought that down–as a by-product of the paté industry–would have an edge. But Cooler’s analysis showed two things: 1) down bears some responsibility for the carbon cost of raising geese, and 2) that portion–however slight–becomes significant due to the intensity of the methane (produced by the geese) as a greenhouse gas. Another surprise: While our contestants cut emissions by 10 percent compared to traditional bags, that’s significantly less than the 30-percent improvement we saw with packs (which are easier to streamline).

How We Did It

To create a baseline measurement, Cooler’s researchers identified the footprint of a standard 20°F sleeping bag made with no recycled materials (400 pounds of CO2). Then they analyzed the impact of specific choices made by bag makers–not just the type of shell fabric, but how the fabric was transported (truck, ship, or train?), how many miles it traveled, the percentage of renewable energy used at the plant, and other factors. In the end, the lowest footprint belonged to Feathered Friends’ Blue Heron, thanks mostly to its lightweight construction and local manufacturing. The other entries were close behind, and all of the bags delivered outstanding field performance. Bottom line: These green bags are as good as any in their category–and their footprint is smaller. Here are the results, in alphabetical order by company.

Big Agnes Tumble Down 20

Less bag where many hikers don’t need it makes a big difference.

Feathered Friends Blue Heron 20

A winning combo: Make it light and local.

GoLite Starlite 20

Recycled materials and fewer trucking miles trim carbon weight.

Sierra Designs Verde 20

No bag in this challenge incorporated more recycled components.

The North Face Green Kazoo 15

How do you replace a legend? Cut its footprint without cutting warmth.

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