martin_e said:
the amount you grow will absorb the carbon dioxide produced by the time you have a crop big enough for your refill ...
An interesting factoid, but I'd like to see how much CO2 is actually consumed, versus the emmissions, as plants only draw in CO2 in the presence of light, for photosynthesis.
Having worked in commercial horticulture (he he...very useful...
) growers run their boilers flat out during the day, primarily to produce CO2, which is piped into the greenhouses, where it is used to enrich the atmosphere and promote crop yeild (usually salad crops). The excess floats up & out the vents...
The massive amount of heat produced is actually a waste product (
... I know) but is stored in large vessels through the day. Then at night, when the plants can't use the CO2, the boilers are shut down, and the hot water stored in the vessels is pumped though the green houses to keep the crop warm.
A slight variation on this theme is for the growers to use gas-powered alternator sets, which produce both heat and power, and the power is pushed into the national grid. These units (CHP = Combined Heat & Power) were also heavilly subsidised for a period of time, as a source of cheap electricity.
I'd be interested to see some of this technology applied to hemp production, which might help balance out the whole circle and realise hemp as a viable alternative.
By comparison, the yellow oil-seed rape, which has now become so prevelant in the production of our margarines, is fuggin 'orrible'!!! Not only is the processing of the stuff a nasty carcinogenic affair (I've also worked in a refinery), the byproduct of which is fed to our cattle, but the crop itself is nasty. I grew up in East Yorkshire, which is nice and flat, and our town was surrounded by arable farming. Over the years I saw wheat crops replaced by this legal yellow weed, for commercial reasons, however, I also saw the number of respiratory related ilnesses, like asthma increase dramatically, in people with no previous history of such problems. Prolonged close contact to the crop will give someone a really bad headache (we used to play hide & seek in the crops), and at crop times, the surrounding towns are flooded with the tiny black flies that live in the crop. These flies are so tiny that they can get between triple glazed windows, LCD screens, and even into microwave door windows. At harvest time it is just like some one sprinkling tea leaves all over you... :sad:
Hemp gets my vote!