The author of today’s post, Sheryl Canter, is an Online Writer and Editorial Manager for the Climate 411 blog.at Environmental Defense.

When it’s apple season here in New York and the green markets are overflowing, for a store to ship in apples from Washington State or New Zealand burns fuel for no good reason. Local food is fresher, tastes better, and supports the community. And locally produced food often results in lower greenhouse gas emissions - but not always. The greenhouse gas calculation is complicated, and you can’t assume that if a crop is produced locally, greenhouse gas emissions are lower.

For starters, the term "food mile" is itself problematic. A mile travelled by a large truck full of groceries is not the same as a mile travelled by a mini-van carrying a crate of carrots. A report published by DEFRA [PDF], Britain’s environment and farming ministry, says it’s more useful to think in terms of "food-vehicle miles" (the miles travelled by vehicles carrying food) and food-tonne miles (which considers the tonnage being carried).

The DEFRA report contains several counterintuitive findings:

• Trucking in tomatoes from Spain during the winter produces less greenhouse gas emissions than growing them in heated greenhouses in Britain.
• A shift towards local food systems might actually increase the number of food-vehicle miles travelled. This is because supermarket-based food systems have central distribution depots, short supply chains, and big full trucks. In local food systems, food is distributed in a larger number of smaller, less efficiently packed vehicles.

But the DEFRA report is not the last word on the subject. The Leopold Center for Sustainable Agriculture found different results in its 2001 study "Food, Fuel and Freeways." They reported that conventional food systems used 4 to 17 times more fuel and emitted 5 to 17 times more CO2 than local and regional food systems, depending on the system and truck type.

A Lincoln University study [PDF] included elements they called "factor inputs and externalities" in analyzing the impact of food miles - for example, the amount of water and fertilizer used, harvesting and storage techniques, means of transport, and dozens of other aspects of cultivation. They found that lamb raised on New Zealand’s lush pastures and shipped 11,000 miles by boat to Britain produced 1,520 pounds of CO2 per ton, while British lamb produced 6,280 pounds. The reason? British pastures provide poorer grazing, forcing farmers to use feed. They found similar results for dairy products and fruit.

There’s a push for "food miles" labeling in both the U.S. and Europe. North Carolina State University’s Center for Environmental Farming Systems is working with FoodLogiQ to develop a pilot program in North Carolina with an eye towards national implementation. Local food is fresher and supports the community, so a locale label can tell you that much. But "local" doesn’t necessarily mean lower greenhouse gas emissions. That depends largely on how the food is produced and transported. Just knowing where the food was produced doesn’t tell you that.

Read more posts on Environmental Defense’s Climate 411 blog.

By Dr. Lisa Moore, Environmental Defense scientist. (Cross posted from Climate411.org.)

Photo: Green OptionsLast week, Yahoo! launched a new site that can calculate how much your carbon dioxide (CO₂) emissions go down when you try their energy saving tips. It's fun to use, and I especially appreciate the snazzy interactive features because I know how hard people worked to build it. My colleagues and I provided the Yahoo! design team with the data they use in their calculations.

I hope you'll visit the site to see how simple changes in your house and car can save energy and lower emissions. But first, let me take you behind the scenes to the complicated world of carbon calculation.

Read the rest of this entry »

By Erica Rowell, Environmental Defense Writer, Editor, ProducerCFL and incandescent bulbs side by side

Quality was spotty in the 70s, but this is a new millennium

Apple computers. Punk. Compact fluorescent light bulbs (CFLs). What do they have in common? They were introduced in the 1970s and are now back in style.

CFLs have improved dramatically from their inauspicious beginnings. They took a while to come on, flickered as they lit and gave off an unpleasant green hue. That was then. CFLs not performing well today is a myth—as fictitious as the urban legend that says Mikey from the Life cereal ad died from noshing on Pop Rocks. He's alive. CFLs rock.

Brighter, whiter, faster

Thanks to improved technology, CFLs are now like familiar old-fashioned incandescent bulbs (ICs) in just about every way. CFLs can be as bright, come on as quickly and provide warm white, eye-pleasing hues. They can even be dimmable and used in 3-way sockets. If you haven't tried a new-fangled CFL, go on, "Try it—you'll like it."

Plus, as their prices have come down and energy rates have ticked up, the savings keep improving. CFLs slash global warming pollution, too.

How CFLs save money and global warming pollution

Turning on a light taps electricity from your local utility. About half our electricity comes from coal-burning power plants and another 20 percent comes from from natural gas, so powering things on generally means spewing lots of heat-trapping pollution. These greenhouse gases drive climate change. So using less electricity means less global warming pollution—and lower electricity bills.

How much savings CFLs rack up

Crunching the numbers is eye-opening. Let's compare a 25-watt CFL costing $3 (a good average price) to a 60-cent, 75-watt IC.

Now, let's turn on both our 10,000-hour CFL and our 750-hour IC bulb at 12:01 a.m. on January 1 and keep them running 24/7 for a year. On December 31, our CFL has racked up extraordinary savings in cash and pollution.

What to look for in energy-saving bulbs

To replace a 75-watt bulb look for a CFL with these specs:

• 20 to 25 watts. CFLs use roughly a quarter of the energy to produce the same light.
• 1200 lumens. This minimum level of brightness provides what you're used to.
• Warm white (or 2700-2850 degrees Kelvin). This color temperature mimics an incandescent light.
• Energy Star symbol. This label indicates high-standards and ensures that the CFLs' claims (brightness, longevity, power used, etc.) are real.
• Get more CFL tips

Time to switch to CFLs and save

Bottom line: CFLs save you money and cut heat-trapping pollution. How much of each depends on things like your electricity rate, the energy mix your utility uses, and which CFLs you buy. (See our chart for info on other bulbs.)

Check out the Environmental Defense CFL guide to get started and see which CFLs are right for your needs. And then turn on your new Mac, crank up the Ramones, and dim your new dimmable CFL.