You may remember a previous post about the impact of coal-mine fires.
Anyway, this is another one for anyone who thinks that global warming is, basically, caused by Americans driving SUVs, or the Chinese building power stations.
Apparently (this is from New Scientist recently) the average American household creates nearly twice as much greenhouse gas by what they eat, as by their car-driving. (Food 13.5% of their footprint, driving 7.3%).
This is mainly because they eat a lot of beef and cows milk (and things made from them). Raising beef is very greenhouse-gas intensive. It's hard to calculate the impact of a food (or any production process) on the atmosphere: you have to consider not only CO2 but all the gases released (eg methane) and their relative impacts. And you have to consider all stages of the process. For example, with beef, you have to consider the methane the cows produce, but also the impact of land cleared to graze them, grain farmed to feed them, fertiliser made to feed the grain, transport at every stage, processing, heating and lighting...
Beef is apparently twice as bad as pork, which is worse than chicken, and all of them are much worse than a vegetarian diet. Livestock, if I understood the article correctly, amounts for about 18% of humankind's impact on greenhouse gases. (I don't know what the other 82% is.) If an American goes vegetarian, it saves more impact than they can save by driving less or driving a more economical vehicle.
So no, it's not all about how Americans have bigger cars than us, or drive further, or have too-cheap petrol, it's more about how they eat mainly beef. As we do.
And, ultimately, about how there are too many humans on the planet.
(And, the part where food gets transported from where it's grown to where it's sold is only about 4% of the impact of the food, so "buying local" doesn't make a huge difference either.)
