[sooyeah]

When I lived in Uganda I could have made 3 times as much by changing from growing matoke (cooking bananas - a staple foodstuff) to coffee. I could have paid my workers more too. However, all the coffee would have been exported and there would have been over 1000 acres less food production for local consumption (not just by my workers). Considering I was getting approximately 35,000-40,000lbs of bananas per acre, that's a lot of food to lose. Get a few dozen producers doing that and suddenly you have a problem.

So do you think, poor countries should give incentives to local farmers to grow staples for home consumption?

[VAlibrarian]

according to all I have read, there are two main causes for the observed rise in the prices of corn, wheat, and rice. first cause is the diversion of large quantities of grains into biofuels. second cause is the change in eating habits of many humans from vegetables and grains to Meats. It takes tremendous amounts of grains to feed cattle to a point that they can be slaughtered. As more and more humans choose to eat more meat, and gain enough money to do so, the human race requires more grain production to feed the cattle, pigs and other livestock. This is a very simple supply and demand situation. If you desire to reduce your impact on our planet it terms of greenhouse gases and the preservation of ecosystems for other species, it is important to eat as little meat as possible (and in the western world most of us eat far more than we need, and far more than is healthy). It is also important to reduce the amount of fuel we use, be it fossil fuel or biofuel. Most biofuel uses a large amount of fossil fuel in production anyway, other than ethanol from sugar cane. The benefits of biofuels were oversold, and the potential negative impacts were undersold, because we feel our oil addiction and see biofuels as a magical answer. the true magic answer is to use renewables such as solar and wind to fuel battery vehicles and public transit.

[m40]

"electric cars are much more efficient and less polluting."

More than three quarters of all electricity in N.America is generated from COAL. Are you therefore advocating coal powered cars, which are made incredibly inefficient by the inherent loss in the electrical distribution system along with the loss of storing to and drawing from batteries? Also, what are you going to do with all those batteries?

"Solar panels that can use UV radiation as well as visible light that is present even with a heavy cloud cover are quite sensible."

Really? You do realize that this is supposed to be a SCIENCE forum, yes? Solar panels are at the most about 30% efficient (under laboratory conditions) and in economically feasible production form, about 10% efficient. With the current pricing of solar panels and their active field life, they are a net negative. This means that electricity from the grid is still cheaper. Nobody has produced a manufacturable, marketable panel that reaches parity with the grid... even in sunny places!


Geothermal energy from ALL parts of the earth is already developed. WHY CAN'T PEOPLE READ THE DATA?

I DO read the data. Most of the geothermal energy in use worldwide is captured via steam generators. This dumps massive amounts of water vapor into the atmosphere, which by all accounts is about 4 times worse than CO2 as a 'greenhouse' gas. You're better off with fossil fuels.

[peppercorn]

Oooo! A reanimated thread! - Super!

More than three quarters of all electricity in N.America is generated from COAL. Are you therefore advocating coal powered cars, which are made incredibly inefficient by the inherent loss in the electrical distribution system along with the loss of storing to and drawing from batteries? Also, what are you going to do with all those batteries?

Not unless you can make a fuel-cell (suitable to fit in a car) run directly off the coal.  What these arguments often seem to take into account is the suitability of a particular fuel for the job in hand. BTW there are such things as 'Direct-Carbon Fuel Cells', but I don't think they are workable in a vehicle-suitable package (they are big!).
Comparing an ICE burning Petroleum with Battery-Electric (even if it is exclusively generated from coal) is still (Well-to-Wheel) a more extensive contributor of CO2 overall.

"Solar panels that can use UV radiation as well as visible light that is present even with a heavy cloud cover are quite sensible."

Really? You do realize that this is supposed to be a SCIENCE forum, yes?
....

None of what you go on to say disproves the previous poster, so why the 'Really?', huh?
That is, if you're building a solar panel (one assumes you are sensible enough to know there is a market for your panel) then making it able to generate some power under cloudy conditions (rather than none at all) makes good sense (provided it's still economic to add this ability).

[peppercorn]

Geothermal energy from ALL parts of the earth is already developed. WHY CAN'T PEOPLE READ THE DATA?

I DO read the data. Most of the geothermal energy in use worldwide is captured via steam generators. This dumps massive amounts of water vapor into the atmosphere, which by all accounts is about 4 times worse than CO2 as a 'greenhouse' gas. You're better off with fossil fuels.

1. I think it depends where (at what strata of the atmosphere) you release the water vapour as to what effect it has on the greenhouse effect.
2. The water vapour that is released in the case of generated steam is already part of the atmospheric cycle - it came out of rivers, etc. It is not like Carbon or Hydrogen freed in burning FFs as they are unbalancing the system (our atmosphere) with a net addition of CO2 and water.

[Geezer]

Most of the geothermal energy in use worldwide is captured via steam generators. This dumps massive amounts of water vapor into the atmosphere,

No, it doesn't. The steam is condensed into water and is reused. But even if it was not, it would still be a minute drop in the bucket compared to the amount of water vapour that the Sun continuously lifts into the atmosphere.