What if humans were always CO2 neutral?

[greenbean36191]

I have no idea how much CO2 the average person exhales per day, but just assuming our average methane belches are a meer one liter per day. that's 6.6 billion liters or 233 MCF of methane per day. or enough to run a 1400 megawatt state of the art combined cycle generating station round the clock. Methane is 21 times more effective as a green house gas as CO2. or equivalent to 5 BCF per day of CO2, plus what we exhale must be much more. Anybody know how much?

We aren't ruminants so we don't belch methane and most farts have little if any.

The C in the CO2 we exhale comes from our food and the C in our food originally came from CO2 via photosynthesis (even if you're eating meat). We exhale less CO2 than the plants originally took up so there is no net increase in atmospheric CO2 as a direct result of respiration unless we eat food faster than it can grow.

Now, land use changes to produce that food can have a big impact on CO2.

 

[kaptken]

Good point GB,
the carbon cycle works fine and neutral as long as things stay in the CO2 to plant to food/fuel cycle. Which is why my fireplace is good. I grow trees out back, cut them down for firewood, and then grow some more. I cant keep up!! the trees are winning!!

But skewing the food chain to cattle, pigs chickens and sheep will also skew waste by product emissions to the more potent GHG, methane. tipping the atmospheric thermal balance. which is what the world is doing by going to meat rich diets.

True, we are not designed to be true ruminants for our sole source of digestion, but we do carry a wide range of bacteria including anerobic Methanogens and can and do produce some methane too.
http://www.microbeworld.org/news/articles/microbiology_farts.aspx
While the amount is not as significant as our domesticated ruminant animals, I was pointing out the cummulative effect of large numbers on seemingly insignificant things we do. I bet everyone knows somebody who has played with matches.

 

[chrissreef]

or 1 cupcake here and there vs 1 at every meal (that darn sweet tooth!) hehe

anyway, great insightful posts!

 

[mfp1016]

I noticed this study has no emphasis on the localization of greenhouse gases. This immediately tells me this study is of little scientific value. Any decent climatologist or physicist would have included those effects, without them its pointless to concoct such graphs.

 

[kaptken]

Well, mfp1016,

While all sources are local, The atmosphere is difuse. California experiences a higher concentration of airborne pollutants from China, because of the hang time, prevailing winds and bcause it takes a while to spread it around the world equally. Yous guys are the first landfall of their effluent.

You are Just lucky, I guess.....