The Contribution of Fossil Fuels in Feeding Humanity

originally posted by: D8Tee
a reply to: Greven

‘Number of pairs’ refers to the number of comparisons in which replicates of a particular cultivar grown at a specific site under one set of growing conditions in one year at elevated [CO2] have been pooled and
mean nutrient values for these replicates were compared with mean values for identical cultivars under identical growing conditions except grown at ambient [CO2]

The paper shows what is to be expected if they do not increase the Nitrogen fertilizer for the increased C02 rates.

Every year on the farm we would take soil samples and sent them in and fertilize accordingly.

You can't expect to change the C02 variable and not change the fertilizer applied to the crop can you?

I'm not an agrologist, but I suspect the crops were nitrogen limited, and the data indicates that.

The nitrogen fixing legumes and sorghum were not as low in protein as the non nitrogen fixing crops grown.

Isn't that what you've been arguing, though? That - ceteris paribus - CO2 increase would have a fertilization effect?

The increased CO2 levels were, by the way, 550 ppm - the expected atmospheric concentration by 2050.

a reply to: Greven

There's more to the fertilization than just the C02 needed or respiration.

There's the whole N-P-K thing that goes along with it, plus the micronutrients.

Get the fertilization wrong, yields and protein will be down.

Yes, I'm aware of what the levels were, I do in fact read most of the papers that people present to me and try to understand where they are coming from.

I do try to advance my own knowledge via these forums and not just paint myself into a corner of indefensible positioning.

a reply to: Greven

That - ceteris paribus - CO2 increase would have a fertilization effect?

Large scale tests were carried out many years ago with excellent results.
Scientific American

originally posted by: charlyv
It would be interesting if a "fossil fuel" phase is common in most alien civilizations, assuming they are biological.
A kick starter, if you will, to advancing to a stage where it can be replaced before it runs out. Would a coal layer have to be unique to Earth, or a planet much like Earth?

Coal and oil come from trees that fell down and also decomposed or liquified but weren't recycled by anything else like termites, ants, fungi or other plants. This may have been due to tsunami, forest fire, sudden flooding, earthquake and ground liquifaction. Then they got buried under other layers of clay and sand, where the water was eventually squeezed out, leaving behind domes of oil and gas under pressure.

It would depend on the chemical makeup of those planets, but if water is necessary to be in a liquid phase, then some hydrocarbons would be present as liquids and others as gases. Photosynthesis requires infra-red and ultra-violet wavelengths of light. Carbon seems to be the backbone of DNA and amino acids form readily in liquid environments with lightning. Then basic growth patterns like branching would create lifeforms like trees and plants.

a reply to: stormcell

Titan and Europa have methane on them, abiotic in origin obviously.

originally posted by: Greven
a reply to: D8Tee

Looks like it's also here if you want to read it.

An increase to CO2 only helps if it's the limiting factor. Greenhouses generally need CO2 pumped in because the plants within consume the CO2 in the semi-enclosed environment. This happens outdoors as well - corn fields, for example, will have reduced CO2 levels at ground level.

How come no where in that paper do they talk about yields of the crops?

It would be interesting to see how the yields were affected with C02 supplementation.

They seem to have left that dog lay, unless I am missing something?

a reply to: D8Tee

The objective of the paper was to determine nutrient content changes.

You could ask them, I don't know the answer.

originally posted by: Greven
a reply to: D8Tee

The objective of the paper was to determine nutrient content changes.

You could ask them, I don't know the answer.

Yield increase has been studied anyways.

It's very real.

Just didn't fit the papers agenda to mention it.

Link to Scientific American