[ClearCase_guy]

Well, I think the whole GW thing is crap, but I think I can explain part of this thinking. Let me cover animals first. In a state of nature there are X number of cattle on the planet. They pass methane, which is a greenhouse gas. Now, with humans and modern farming methods, the number of cattle on the planet is probably "X times 10,000" and the amount of methane is increased "beyond what is natural".

Just so, with agriculture. If you clear an acre of forest, and plant an acre of corn and harvest and re-grow it annually, I would think that the impact on CO2 levels would be "beyond what is natural".

Let me be clear: I don't think any of this matters. The sun warms the plant. End of discussion. But I think it is still OK to say that human agriculture can have a greater impact than natural vegetation.

[ClearCase_guy]

Although the sun does "warm the plant" I meant to say the sun "warms the Planet".

[Bernard Marx]

I think it is still OK to say that human agriculture can have a greater impact than natural vegetation.

Possibly. The thing is, we don't really know. Ever-increasing human populations contribute humungous amounts of methane as well. How many "cattle" were there in a state of nature? Last I heard there are more trees in the U.S. now than when Columbus arrived in the New World, and forests are extending their ranges northward.

My criticism is based on the fact there are no hard data in the study. If you can quantify and actually compare Mammoth Herd X to Black Angus Herd Y, and so many million acres of Tempskya Fern in the Jurassic to an actual amount of present day sorghum (plus crop rotation cycles) then I might pay attention. But it's all Blue Sky academic posturing.

[Pan_Yans Wife]

Did you hear that in Australia, the farmers are now charged a methane tax, because of environmental impact? :)

[lepton]

Let me cover animals first. In a state of nature there are X number of cattle on the planet. They pass methane, which is a greenhouse gas. Now, with humans and modern farming methods, the number of cattle on the planet is probably "X times 10,000"

Let me cover animals first. In a state of nature there are X number of cattle, and Y number of Bison on the planet. They pass methane, which is a greenhouse gas. Now, with humans and modern farming methods, the number of cattle on the planet is probably "X times 10,000", while numbers of Bison have plummetted to an insignificant fraction - though the flatulence of ill-fed cattle is higher than those that are well fed, and the cattle in India are among the most flatulent of all.