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Author Topic: Green Cars. Solution or Aggravation!!  (Read 1696 times)

Offline hamza

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Green Cars. Solution or Aggravation!!
« on: 25/09/2007 08:32:32 »
According to the following wikipedia link
http://en.wikipedia.org/wiki/Greenhouse_effect
; water vapours are thought of causing 36% of the greenhouse effect thus causing global warming, while CO2 contributes far less i.e 12%. So my question is why are the electrical green cars, which work on the principle of emitting water vapours instead of CO2, thought as a solution to greenhouse effect, whereas they are actually aggravating the problem..
« Last Edit: 25/09/2007 08:35:08 by hamza »


 

Offline daveshorts

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Green Cars. Solution or Aggravation!!
« Reply #1 on: 25/09/2007 10:59:47 »
The amount of water vapour in the atmosphere is mostly dependent on the temperature, as the higher the temperature the more evaporates from the oceans. The amount that cars would put out would be a minor issue. It will just fall as rain fairly soon.
 

another_someone

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Green Cars. Solution or Aggravation!!
« Reply #2 on: 25/09/2007 13:54:31 »
The amount of water vapour in the atmosphere is mostly dependent on the temperature, as the higher the temperature the more evaporates from the oceans. The amount that cars would put out would be a minor issue. It will just fall as rain fairly soon.

The saturation point - the amount of water vapour the atmosphere can hold, is dependent on temperature, but a lot of the air is less than 100% saturated, and so factors other than temperature must come into play.

Water added to the air in Singapore would probably make little difference, since the air is already at very close to saturation much of the time; but the same in other parts of the world I would imagine would have a different outcome.

In other respects, ofcourse, the amount of water evaporated from the seas is dependent upon temperature.  On the other hand, at present, most of the water in the atmosphere comes from this source; but if we start pumping more water into the atmosphere, how does this interact with water already in  evaporated from the sea.  Will maritime evaporation be reduced because the air is already more saturated, or will it just increase coastal precipitation?

Ofcourse, as a greenhouse gas, it also has a feedback mechanism of its own - since the more water vapour in the air, so the warmer the air, and so the greater amount of water vapour the air is capable of holding, and so the greater the greenhouse effect.

As for the amount of water cars put in the atmosphere - the problem is that when any technology is new, its usage is light, and its effects are slight (at the start of the motor car era, people would have regarded all aspects of environmental influence of the motor car as slight, because there were not many of them).  The question has to be what happens when you scale things up.
 

Offline McQueen

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Green Cars. Solution or Aggravation!!
« Reply #3 on: 26/09/2007 02:20:10 »
With approximately 500 million cars on the road, not counting two-wheelers, buses trucks and other forms of commercial transport, cars are the most potent source of pollution, followed closely by aeroplanes.  The whole point of green cars is not only to help with environmental problems but also to save what fossil fuels we have in reserve, until a more dependable alternate source can be found. So the development of a green car is important maybe even critical at this stage. As for cars, such as fuel cells, that emit only waters as an end product, they could have a very serious impact, they might in fact lower the temperature enough to bring about another ice age! No kidding, it is possible, every time water is emitted it is taking some heat from the atmosphere, so if you have a couple of humdred million cars, not counting buses and other forms of commercial  transport, it is going to reduce the temperature pretty quickly, even if each car only takes a few calories of heat from the atmosphere, it all adds up. McQueen
 

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Green Cars. Solution or Aggravation!!
« Reply #3 on: 26/09/2007 02:20:10 »

 

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