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Global Warming: The Scientific Facts

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(@Anonymous 15703)
Posts: 1312
 

This new govt will be just like it was last time it was in, commit to every protocol, spend every cent on everything, say sorry to the stolen generation when we should be sorry for not taking a pile more out of squalor right now. This govt got in because a pile of current voters didn't have houses or creditcards last time they were in and they all have a job now if they want one. Kyoto is a huge joke it ties modernised countrys already striving for economical reduction in polution so that our products are unviable. What do we do? buy the products from up and comming countrys that are destroying the environment. As for scientists theyre now saying electricity from turbines in dams on rivers produce too much greenhouse gas what a lot of BS


 
Posted : November 26, 2007 9:41 pm
(@wouter)
Posts: 9363
Three Star Admiral Registered
 
Quote
Then explain to me why my brother's gas pickup ... (has) less fuel economy?

Only after you have explained to me why you think it has less fuel economy ?


 
Posted : November 27, 2007 7:14 am
(@wouter)
Posts: 9363
Three Star Admiral Registered
 
Quote
Audi has been pounding the 24 hr Le Mans the last few years with a diesel engine mainly on not having to stop for fuel as frequently.

That is more the result of diesel having a higher energy content per liter (volume) then gasoline ; not that the diesel engine is so much more efficient in energy conversion (although it is a little more efficient). On the other hand diesel also weights more. It is very interesting to note that the 18% higher energy content of Diesel is mirrored by it also weighting 18% more per given volume.

But even more dependable sources are a little bit confused (see the second paragraph)

From wikipedia : http://en.wikipedia.org/wiki/Diesel

The density of petroleum diesel is about 850 grams per litre whereas petrol (American English: gasoline) has a density of about 720 g/L, about 15% less. When burnt, diesel typically releases about 40.9 megajoules (MJ) per litre, whereas gasoline releases 34.8 MJ/L, about 15% less. Diesel is generally simpler to refine from petroleum than gasoline and often costs less ... Also, due to its high level of pollutants, diesel fuel must undergo additional filtration which contributes to a sometimes higher cost. In many parts of the United States and throughout the whole of the UK, diesel is higher priced than petrol.[1] Reasons for higher priced diesel include the shutdown of some refineries in the Gulf of Mexico, and the switch to ultra-low sulfur diesel (ULSD), which causes infrastructural complications.[2]

Diesel-powered cars generally have a better fuel economy than equivalent gasoline engines and produce less greenhouse gas pollution. This greater fuel economy is due to the higher energy per-litre content of diesel fuel and also to the intrinsic efficiency of the diesel engine. While diesel's 15% higher density results in 15% higher greenhouse gas emissions per litre compared to gasoline,[3] the 20–40% better fuel economy achieved by modern diesel-engined automobiles offsets the higher-per-liter emissions of greenhouse gases, resulting in significantly lower carbon dioxide emissions per kilometre.[4][5]

******

First they define fuel economy as per liter of fuel, which will get the author lose his engineering title if he ever tries to pass it as energy conversion efficiency in any scientific publication. Still, a common reader will definate equate the two and thus be errornously informed. Then they produce another gem. Then they say :

... the 20–40% better fuel economy achieved by modern diesel-engined automobiles offsets ...

So first we need to subtract the 15% better fuel economy (as they define it) due to the higher energy content per volume. So we end up with the Diesel engine being 5% to 25% more energy conversion efficient then a gasoline engine which is typically about 20-25% in non stationary operation. Of course this means that a diesel engine will have the following efficiency range in stationary operation : 105%*20% to 125%*25% = 21% to 32%

I know that their

20–40% better fuel economy

sounds alot better (in marketing) but the real SCIENTIFICALLY sound numbers (- energy conversion efficiency) are only 21%-32% for Diesel compared to 20%-25% for gasoline. A difference indeed, but not a huge difference.

I think Hybrid-cars get better ratios then both, mostly because in that setup the engine can be run stationary which will be more efficient still. Even better would be a practical fuel cel setup as that totally circumvents the thermodynamic processes and heat loses that are implicit in combustion engines. As a result a fuel cel is not limited to the max theoretical Carnot energy conversion efficiency of 55%-65%. As a result the practical efficiency can be much higher as well. I had expected a practical fuel cet setup by now but something is holding it up.

Wouter


 
Posted : November 27, 2007 7:33 am
(@flatlander)
Posts: 1108
Master Chief Registered
 

Trucks may be different but, in cars, in the USA, diesel doesn't make sense economically (bottom line). A (~) 15 to 20% boost in mpg is offset by the 15 to 20% higher price of the fuel. Then look at who offers diesel autos, it's Volkswagon, unless of course you'd like a VW. In the US the highest priced auto, maintenance wise, is anything European. Doesn't make fiscal sense to own diesel. My neighbor has a diesel Passat...very nice car, I had to ask what the TDI stood for! I'll stick with second hand, Pacific rim, gas powered for now. Regardless of effect on the planet, I'm moving in what gets me around in the most economical and expedient fashion. I wont ride the bicycle to the market on Saturday morning because the car will get me there and back faster giving me more time to do what I want (sail maybe?).

Call me very lucky, I have a choice, that's were I suppose a lot of us get rubbed the wrong way. Maybe when I retire I'll ride the bicycle to the market. Maybe when I retire it wont be as important to shave a few hours off the regatta commute and I wont mash the gas pedal to the floor at every chance. Then again, maybe I'll be that old man putzing around in that 60's supercar that gets 8 mpg, that I may have to pour lead additive in the tank to get it to run proper. I don't see the majority of Americans wantingly wasting fuel (except for maybe the occasional Karl <img src=

alt=

/>) we just want to have a choice.


 
Posted : November 27, 2007 9:20 am
(@Anonymous 39155)
Posts: 3112
 

http://autoshow.autos.msn.com/autoshow/LA2007/Article.aspx?cp-documentid=5729898

Just for you Karl.


 
Posted : November 27, 2007 9:35 am
(@wouter)
Posts: 9363
Three Star Admiral Registered
 

22 mpg on the highway = 9.4 km/liter

That is pretty unimpressive in absolute sense.

All larger EU and Jananese family cars get at least that mileage without being hybrid or anything. But of course it is much easier to get the town market on sunday in a vehical that is the size and weight of a Patton Tank. Honestly I have no idea how we in Europe and Japan can survive like this.

Basically all technological breakthroughs that many hope for are and will be used by US drivers to drive even bigger and heavier cars, leaving the net gains at zero ! Like that we will be getting nowhere.

Wouter


 
Posted : November 27, 2007 10:51 am
(@Anonymous 39155)
Posts: 3112
 

That's a 30% improvement! We should hit $4/gallon within 18 months (if not sooner). I can already see fewer SUVs on the road here.

The market has spoken! Price is going up, straight up!


 
Posted : November 27, 2007 11:59 am
soulcat01
(@soulcat01)
Posts: 44
Lubber Registered
 
Quote
Trucks may be different but, in cars, in the USA, diesel doesn't make sense economically (bottom line). A (~) 15 to 20% boost in mpg is offset by the 15 to 20% higher price of the fuel.

Your math isn't totally accurate, and it's just recently that your argument could even be entertained. Even with your faulty math it looks like it's an economic wash. And what type of cars are we talking about comparing?

Only in the last 6 months has diesel cost more than gas. Why is that, it's less refined? (There's the scam!) And they don't add any oxygenate like MTBE. That crap is toxic and is in the flesh of every fish you eat.

Just 2 years ago I was paying $1.65 per gal for diesel and gas was $2.30 +or-. Now diesel here is $3.69 and gas is $3.58. Just filled up with biodiesel at $3.25 over at Austin Biofuels. And I get 45 to 50 MPG. Do the math for me, I'm too lazy.


 
Posted : November 27, 2007 1:16 pm
(@flatlander)
Posts: 1108
Master Chief Registered
 
Quote
Quote
Trucks may be different but, in cars, in the USA, diesel doesn't make sense economically (bottom line). A (~) 15 to 20% boost in mpg is offset by the 15 to 20% higher price of the fuel.

Your math isn't totally accurate, and it's just recently that your argument could even be entertained. Even with your faulty math it looks like it's an economic wash. And what type of cars are we talking about comparing?

Only in the last 6 months has diesel cost more than gas. Why is that, it's less refined? (There's the scam!) And they don't add any oxygenate like MTBE. That crap is toxic and is in the flesh of every fish you eat.

Just 2 years ago I was paying $1.65 per gal for diesel and gas was $2.30 +or-. Now diesel here is $3.69 and gas is $3.58. Just filled up with biodiesel at $3.25 over at Austin Biofuels. And I get 45 to 50 MPG. Do the math for me, I'm too lazy.

kansas city gas prices proof of TODAY, not two years ago.

Math for dummies
$2.77/$3.29= 16%
$3.29/$2.77= 19%
figured both ways (depends on how soulcats cook their numbers)

2005 Passat gas 4cylinder 2005 Passat diesel 4 cylinder Think those are flipped, used the combined MPG
22mpg/27mpg= 19%
27mpg/22mpg= 23%

You busted me, I'm at fault, if we average these two figures and balance the book cooking we come up with 21% and 17.5% Excuse me I'm way off in the weeds with these FACTS.

Go to edmunds online and compare

true cost to own

on a (for instance) 2005 Passat, gas and diesel version. You'll find the diesel will cost $1,406 MORE to own over a five year period. Obviously skewed numbers and fuzzy math.

Why did I even waste my time?


 
Posted : November 27, 2007 2:19 pm
soulcat01
(@soulcat01)
Posts: 44
Lubber Registered
 
Quote
Math for dummies
$2.77/$3.29= 16%
$3.29/$2.77= 19%
figured both ways (depends on how soulcats cook their numbers)

Passat diesel 4 cylinder Think those are flipped, used the combined MPG
22mpg/27mpg= 19%
27mpg/22mpg= 23%

Your specific example sort of works out. That's why I asked what cars you were comparing. What if I generalized and plugged the VW Lupo into your formula? It gets over 80mpg on a turbocharged, electronically controlled diesel.

In your first post you generalized diesel:

Quote
Trucks may be different but, in cars, in the USA, diesel doesn't make sense economically (bottom line).

Any 'dummy' can take apples and compare them to oranges and come up with the desired

math for dummies

.

My 2001 Jetta gets 45 -55 mpg all the time, averaging around 50. That's no skewed apples to oranges argument. It has cost me no more than a regular Jetta to own.

To make it fair pick another mid sized sedan, and compare it with the numbers above. If you're talking strictly monetary bottom line, then it's not a huge amount better. I bought my car to run strictly on biodiesel and straight veg oil, which is about an 85% reduction in hydrocarbon emissions. My personal bottom line. And I try to support the troops by not funding terrorists. Plug those variables into your formula.


 
Posted : November 27, 2007 3:49 pm
(@tiger)
Posts: 66
Lubber Registered
 
Quote
Math for dummies
$2.77/$3.29= 16%
$3.29/$2.77= 19%
figured both ways (depends on how soulcats cook their numbers)

2005 Passat gas 4cylinder 2005 Passat diesel 4 cylinder Think those are flipped, used the combined MPG
22mpg/27mpg= 19%
27mpg/22mpg= 23%

Weird math ... Not convinced.

Add a stickshift on these and you get 10% at the minimum better mileage.


 
Posted : November 27, 2007 5:18 pm
 Karl
(@sogncab)
Posts: 3551
Member
 
Quote
Quote
Then explain to me why my brother's gas pickup ... (has) less fuel economy?

Only after you have explained to me why you think it has less fuel economy ?

Because I get 20mpg, and he gets 15mpg running around empty. Throw heavy trailer on and the gap gets bigger.


 
Posted : November 27, 2007 6:39 pm
 wgb1
(@wgb1)
Posts: 100
Member
 

Here is a report by Dr. R M Carter, from the Marine Geophysical Laboratory, James Cook University, entitled
The Myth of Dangerous Human-Caused Climate Change Very good read.


 
Posted : November 27, 2007 8:53 pm
(@wouter)
Posts: 9363
Three Star Admiral Registered
 

Quote
Because I get 20mpg, and he gets 15mpg running around empty.

We have already established that a gallon of gasoline can not be compared to a gallon of diesel as both have different energy contents. Apples and oranges.

We must first equalize both energy inputs when analysing the (conversion) efficiency of the two engines. Looking at volumes (gallons) is not doing that.

But what am I doing here ? I've explained this several times already in my other posts and you still don't get it. Why would you understand it now ?

Wouter


 
Posted : November 27, 2007 9:10 pm
 Karl
(@sogncab)
Posts: 3551
Member
 

I understand what you are saying wouter. It's just not how people, (me), percieve buying fuel for there vehicle. We don't buy it by the BTU, we buy it by the gallon, or liter in your case. And when we use it we do it as a mile per gallon. Or k/l, whatever.


 
Posted : November 27, 2007 9:17 pm
(@flatlander)
Posts: 1108
Master Chief Registered
 
Quote
Here is a report by Dr. R M Carter, from the Marine Geophysical Laboratory, James Cook University, entitled
The Myth of Dangerous Human-Caused Climate Change Very good read.

Communism (has been) replaced by ambitious environmentalism

Hoo-ya, good stuff eh?


 
Posted : November 27, 2007 10:36 pm
(@wlrottge)
Posts: 835
Chief Registered
 
Quote
....which is why it's a difficult for non-scientists to 'believe'.

What about us engineer/science people that work in environmental air emissions and DON'T believe??? is it hard for me?? <img src=

alt=

/>

www.junkscience.com


 
Posted : November 27, 2007 11:25 pm
(@calebtar)
Posts: 756
Member
 

What about us engineer/science people that work in environmental air emissions and DON'T believe??? is it hard for me?? <img src=

alt=

/>

Agree, having spent 40 years in a related field.


 
Posted : November 28, 2007 1:39 am
(@calebtar)
Posts: 756
Member
 

http://macnelly.com/
select the strip Dec.3 <img src=

alt=

/>


 
Posted : December 4, 2007 3:03 am
(@Anonymous 11644)
Posts: 17
 

Timbo you say that the ice caps are melting, did you read that Ice thicknesses are increasing both on Greenland and in Antarctica. Just wondering as you and many others keep missing this point.


 
Posted : December 4, 2007 10:53 am
(@Anonymous 13024)
Posts: 4319
 

Where did you read that? Any pointers?


 
Posted : December 4, 2007 11:06 am
(@Anonymous 11644)
Posts: 17
 

It is on NASA's website and was released by them. From all reports it’s the most accurate record of polar cap measurements. No politics involved just measurements over time. I am not at all worried about Global Warming just like my father was not concerned about global cooling reported in the 1970's. China and many of the 3 world counties are not going to do anything to reduce their negative affects on the environment, but I believe regardless that fact the US can do its part without damaging the economy, etc.


 
Posted : December 4, 2007 6:16 pm
 Karl
(@sogncab)
Posts: 3551
Member
 

I saw something on discovery channel the other night that said the oceans were once about 150ft lower than they are now! Course 3/4 of N. America was covered in ice. I'd have to trade in the FXone for a DN


 
Posted : December 4, 2007 6:43 pm
(@wouter)
Posts: 9363
Three Star Admiral Registered
 

I guess the cave men at that time thought that their global warming was just another hype as well. <img src=

alt=

/>

Wouter


 
Posted : December 4, 2007 8:21 pm
 Karl
(@sogncab)
Posts: 3551
Member
 

When your life expectancy is probably 18 as a caveman I don't think you care.


 
Posted : December 4, 2007 9:52 pm
Gary
 Gary
(@hobiegary)
Posts: 826
Chief Registered
 

Rolf,

Thanks for posting your blogspot link. Now I have finally figured out what your

avatar

is.

GARY


 
Posted : December 4, 2007 11:58 pm
 wgb1
(@wgb1)
Posts: 100
Member
 

I never knew either until I was motivated to check it out after your post.Hand built wood boats of any type are cool. I built a wooden stitch and glue kayak. There is a gentleman that lives near me and told the story of building a 44' catamaran by himself. He said he sailed away with 2500 bucks. After 5 years of sailing around the world, living on remote islands and other unique locations, he returned home. I thought the story seemed a little far fetched, but he has an album of newspaper articles, photos and other documents from around the world as proof. Neat story.


 
Posted : December 5, 2007 10:56 am
(@Anonymous 39155)
Posts: 3112
 

Bjoern Lomborg of Denmark, one of the world's leading climate change skeptics, is cited in my local paper as being accused of a

stealth attack

on mankind.

Anyone know what all the excitement is about?

http://www.lomborg.com/news/

There's a famous claim that somebody told me from Harvard Law School, that if you have a good case you should pound the case, but if you have a bad case you should pound the table.

B.L. <img src=

alt=

/>


 
Posted : December 14, 2007 12:55 pm
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