http://breakingnews.ewg.org/meateatersguide/a-meat-eaters-guide-to-climate-change-health-what-you-eat-matters/

The lifecycle assessments are based on conventional rather than pasture-based or organic systems of food production. We focused on conventionally produced, grain-fed meat because that is mostly what Americans eat. Also, we were unable to identify definitive studies and widely accepted methodologies assessing greenhouse gas emissions from pasture-raised, organic or other meat production systems that make use of more environmentally sound management practices (such as cover cropping and intensive grazing). Because climate is just one of many factors to consider, our report also assesses other environmental and health impacts of all kinds of meat and dairy, including conventional, organic and pasture-raised. The analysis included salmon and tuna but focuses mostly on livestock and much less on seafood due to data and resource constraints.

Yawn. It's also clear they have an axe to grind. They say that avoiding meat is a good way to reduce teh ebil saturated fat in the diet.

This would really come down to whether you believe "climate change" to be man made or natural cycles that would occur with or without us here. I hate topics like this here, I don't feel like I can even comment on this without being attacked - as has happened in the past.

Note that the calculation is for emissions per 4oz of each food. But there is a lot more useable protein in steak than in potatoes! I'd like to see how it would look if emissions were plotted as emissions per 80g of useable protein (enough to sustain me for one day).

This graph is very flawed. Nowhere does is mention anything about sourcing local foods which has a LARGE impact on your carbon footprint.

Since when did mercury in fish and over-fishing have anything to do with GHG emissions (obviously besides the diesel boat engines). ANd the fat content of milk has NOTHING to do with GHG emissions.

The author of this chart definitely has an agenda.

I doubt it's fully correct. A lot of the data in some past estimates has been found to be flawed. Also notice that while they recommend grass fed beef over regular, they don't break out the difference in impact. I'll try to track down some of the info on flawed past estimates.

Added: Still hunting. I know one of the issues that came up in the estimates (especially the ones Robbins used) was that water use was estimated as though the cattle had spent their entire life on feedlots, whereas most cattle spend most of their time on pasture and are then moved to feedlots for fattening with grains etc (you don't want to know the etc) In pasture a lot (not all) of water comes from ponds where in feedlots it's all supplied. Can't compare pond water that fell from sky onto pasture and the cattle recycles to the pasture to the hideous pollution etc. of feedlots.

EWG should break the figures out for local, grass fed and finished, esp since much pasture land is not ideal for crops - too sloped, too rocky, too dry.....

The other thing they really should look at is impact of Big Ag versus local, sustainable.

Added: Another thing to take into account: One of the largest sources of waste in raising meat is from growing the grains to feed them. High pesticide use (their grown in huge monoculture fields = lots of pests and disease build up and move from host to host) high irrigation in some areas, high fertilizer use and runoff into streams (big pollution problem), lots of erosion of topsoil in tilled culture and some even in no-till. Our current big ag way of raising meat is where most of the environmental damage comes in. Even small farms can cause damage if overstocked or poor pasture management, but this is nothing compared to big ag damage.