I just posted the following comment on Chris Mooney's excellent blog "The Intersection", at its new home on the Discover Magazine website. Here's the discussion thread that prompted this. See there for a video clip of George Stefanopoulos' interview with Rep. John Boehner (R-Ohio) (whose House homepage currently leads off with "Ohio’s coal industry employs about 3,000 people ... Coal and the Ohioans who depend on it are also quietly under attack, courtesy of the federal government" - because of the proposed CO2 cap-and-trade legislation, which he opposes.)
Chris wrote an editorial in response to Boehner's remarks, and in the blog entry he follows some of the response to his position. You might want to view the 2 minute clip and read the blog post as context for the following.
Here's what I posted on Chris' blog:
I’ll second the notion that Boehner’s red herring about CO2 not being a “carcinogen” is more revealing than his mentioning cows as a source of CO2. Technically, it’s true that cow “eructation” can include some CO2, but the video clip makes it clear Boehner was trying to deflect George’s question of whether climate change is a serious problem by tossing up the meme that CO2 is natural (yes) - implying that it can’t then be harmful (no!) - that’s the point of Mass. v. EPA and the new Finding of Risk: spiking GHG concentrations pose large environmental risks from drought, severe weather events, sea level rise and ocean acidification; these not based on any claim of toxicity of CO2, and Boehner ought to know that. He’s just playing a rhetorical card - one that I’m sure plays well for his base.
When it comes to cows, a key point missed in many of these superficial debates is that the US population of cattle is around 100 million - one cow per every three Americans - and we fatten them on subsidized ADM corn in CAFOs (Confined Animal Feeding Operations), not on grass. This is entirely unnatural for cattle; corn is much harder for cattle to digest than the grasses on which they are naturally adapted to ruminate. This causes them to “eructate” a lot more methane than cows grazed on grass. Here’s a recent article on cows and GHGs:
http://www.sciam.com/article.cfm?id=the-greenhouse-hamburger
Fattening cattle on corn instead of grass also gives them acid indigestion, promoting growth of dangerous e-coli, requiring lots of antibiotics not needed for grass-fed cows, greatly increasing the risk of antibiotic resistant strains. Some of these really nasty e-coli find their way into our food supply, leading to food poisonings and mass recalls. This is documented in detail in the compelling bestseller _The Omnivore’s Dilemma_ by Michael Pollan - highly recommended reading!
But getting back to climate change, methane is indeed the #2 greenhouse gas (pardon the expression) after CO2. Concentrated feedlots can’t recycle the volumes of manure they yield, so it stews in manure “ponds” (devastating if they spill into waterways, as seen recently) where it ferments into yet more methane.
Rice farming, landfill garbage, and leaks from natural gas pipelines are other significant human sources of excess methane; wetlands and peat bogs are natural sources. Thawing of permafrost in the tundra is expected to add lots more methane as the climate warms (a big temperature-to-greenhouse-effect positive feedback.)
One methane molecule has some 21 times the greenhouse warming effect of one CO2 molecule; it takes around eight to ten years for methane in the atmosphere to oxidize into CO2 (adding yet one more CO2 molecule that will persist for on average 100 years).
Methane concentrations today are almost triple their pre-industrial levels. While those in denial about climate used to crow about a recent “plateau” in this very elevated level, there is recent evidence of levels starting to rise again, such as here:
http://earthobservatory.nasa.gov/Newsroom/view.php?id=35856
Anyway, it’s clear that Boehner did not want to answer George’s persistent questions (props to George for focusing on the real issue). Boehner kept jumping ahead to “we shouldn’t act if China won’t” - which completely fails to answer the question about CO2!
I believe this illustrates the problem we are up against: many conservatives have already decided that capping CO2 will be too costly, will push jobs overseas, etc. From that point, they work backwards to choose talking points that cast doubt on the science
