Dear EarthTalk: We’ve been hearing for years how producing red meat is bad for the environment while consuming it is bad for our health. How do other types of meat, fish, dairy and vegetable proteins stack up in terms of environmental and health impacts?     -- Julia Saperstein, via e-mail

Not all forms of protein are created equal as to the environmental and health implications of raising and consuming them. A 2011 assessment by the non-profit Environmental Working Group (EWG) found that “different meats and different production systems have varying health, climate and other environmental impacts.”

The quantity of chemical fertilizers, fuel and other “production inputs” used, the differences in soil conditions and production systems and the extent to which best practices such as cover cropping, intensive grazing or manure management are implemented all affect the amount of greenhouse gas emissions a meat product is responsible for generating. To wit, lamb, beef, cheese, pork and farmed salmon raised “conventionally” (e.g. with inputs including hormones and antibiotics and feed derived from crops grown with chemical pesticides and fertilizers) were determined by EWG to generate the most greenhouse gases.

EWG partnered with the environmental analysis firm CleanMetrics to assess the climate impacts via lifecycle assessments of 20 popular types of meat, fish, dairy and vegetable proteins. EWG’s assessment calculated the full “cradle-to-grave” carbon footprint of each food item based on the greenhouse gas emissions generated before and after it left the farm—from the pesticides and fertilizer used to grow animal feed all the way through the grazing, animal raising, processing, transportation, cooking and even disposal of unused food (since some 20 percent of edible meat gets thrown away by Americans).

According to EWG, conventionally raised lamb, beef, cheese and pork also generate more polluting waste, pound for pound. Of these, lamb has the greatest impact, followed by beef and then by cheese—so vegetarians who eat dairy aren’t off the hook. “Beef has more than twice the emissions of pork, nearly four times more than chicken and more than 13 times as much as vegetable proteins such as beans, lentils and tofu,” summarizes EWG. 

On the health front, EWG reports that “eating too much of these greenhouse gas-intensive meats boosts exposure to toxins and increases the risk of a wide variety of serious health problems, including heart disease, certain cancers, obesity and, in some studies, diabetes.”

Besides cutting out animal-derived proteins altogether, the best thing we can do for our health and the environment is to cut down on our meat consumption and choose only organic, humane and/or grass-fed meat, eggs and dairy. “Overall, these products are the least harmful, most ethical choices,” says EWG, adding that grass-fed and pasture-raised products are typically more nutritious and carry less risk of bacterial contamination. “While best management practices can demonstrably reduce overall emissions and environmental harm, the most effective and efficient way to reduce greenhouse gas emissions and environmental impacts from livestock is simply to eat, waste and produce less meat and dairy.” For more information, check out EWG’s free online “Meat Eater’s Guide.”



CONTACTS: EWG Meat Eater’s Guide, www.ewg.org/meateatersguide.

Dear EarthTalk: I recently saw an article extolling the virtues of natural gas as an abundant, inexpensive and domestically produced automotive fuel. Is this going to be the automotive fuel of the future and how green is it?                    -- Jason Kincaide, New Bedford, MA

It is difficult to say which of the growing number of fuel options will power the cars of the future. But natural gas, given its domestic abundance, low price and lesser carbon footprint, is certainly a contender, at least as far as researchers at the federally funded Argonne National Laboratory are concerned. Some of the same engineers there who developed the batteries now used in electric cars have been tasked with improving natural gas powered engine technologies, thanks to anticipated consumer demand for vehicles powered by something cheaper and greener than gasoline but without the hassles of other alternative fuels.

“Our conclusion is that natural gas as a transportation fuel has both adequate abundance and cost advantages that make a strong case to focus interest in the technology as a real game changer in U.S. energy security,” Mike Duoba, an engineer at Argonne’s Transportation Technology Research and Development Center outside of Chicago, told the Talking Points Memo news blog. “In terms of consumer ownership and use costs, the case to make a switch from current fuels to compressed natural gas (CNG) is much more compelling than for other alternative fuels like ethanol and electricity.”

Given this promise—in addition to a February 2012 Department of Energy announcement of a $30 million competition aimed at finding ways “to harness our abundant supplies of domestic natural gas for vehicles”—Duoba and his colleague have been ramping up vehicle systems analysis and engine research and testing around CNG as a way to wean ourselves off of foreign fuel sources. 

Their goal is to improve the efficiency of the CNG combustion process so that it can fit into a new line of engines that can run on gasoline or CNG equally as well, giving consumers the flexibility of choice without any trade-offs. Duoba thinks such a vehicle would have significant consumer appeal, especially in light of sluggish sales of the latest round of electric vehicles from the major automakers.

“At least for some time, compared to plug-in vehicle batteries, CNG storage offers lower weight, higher energy storage and lower costs—as well as faster refueling/recharging.” And while CNG vehicles would generate emissions from their tailpipes, the Argonne team believes that their overall emissions footprint would be smaller than that of an electric vehicle drawing power from the fossil-fuel-based electric grid. 

But to Duoba the appeal of CNG is more about reducing America’s dependence on foreign oil sources than on saving the planet. “Various technologies have been successful at reducing the environmental impact (criteria pollution) over the decades,” Duoba wrote. “To the extent that consumption of foreign petroleum has not been reduced to acceptable levels, this could be viewed as the principal motivation.”

But CNG faces the same major hurdle to becoming widely accepted as any other challenger to gasoline as king of the road: a lack of refueling stations. Whatever does finally unseat gasoline will no doubt have to have a system for refueling that rivals the convenience we’ve come to expect from our corner gas stations.



CONTACTS: Argonne Center, www.transportation.anl.gov.


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