Air travel less harmful to the environment than rail travel?

On 14 Aug, 10:08, James Robinson wrote:
mrtravel wrote:
Randy Hudson wrote:

Nelson wrote:

Aircraft leave vapour trails which aid in the reflection of
the sun's radiation back into space.

A study of the no-fly period following 9/11 showed a full extra
degree (Celsius) of cooling over the US during those four days,
apparently due to the lack of contrail vapor, which contributes to
the cirrus cloud layer that reflects nighttime longwave radiation
back to earth.

Can you cite a source for this report showing the entire US dropped
exactly one degree Celsius and that was directly attributable to the
reduction in aircraft?

Here's one article on the effect:

http://www.sciencenews.org/articles/20020511/fob1.asp

There are lots of other examples.- Hide quoted text -

- Show quoted text -

Thank you for the reference

Amtrak uses about half the energy in Btu per passenger-mile than an
aircraft according to http://www.bts.gov/publications/nati...ble_04_20.html
"In recent years, the company has spent millions on track
improvement, including electrification and straightening curves, as
well as $710 million on 20 new trains sets modeled after the French
bullet train, but not as fast. "

That is very interesting. The other half of the energy budget has
gone on infrastructure.
This is why it costs (for two) £408 to get to Madrid by rail and only
£169 to return by air.

Air travel less harmful to the environment than rail travel? My
conclusion is that there is not much in it.

http://socialgoals.com/blog/2006/12/...e-diverse.html

"In June 2004, 'Modern Railways' published an article ("Rail loses the
environmental advantage") pointing out that high-speed rail can consume more
fuel per passenger than cars or even planes."

--
Policy as if outcomes mattered
http://SocialGoals.com
http://SocialGoals.com/blog/blog.html
"Nelson" wrote in message
oups.com...
Air travel is probably less harmful to the environment than rail
travel. Aircraft leave vapour trails which aid in the reflection of
the sun's radiation back into space. As these trails are at high
altitude their shadows cover immense areas. On the other hand vast
quantities of fossil fuels are burnt to produce the electricity (at
only 10% efficiency) to power the railways. If someone would do the
calculations, all things considered (the upkeep of track and bridges
for instance) they would probably find that Aircraft are less of a
cause of global warming than an equivalent railway system.




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On Aug 13, 1:54 pm, Nelson wrote:
altitude their shadows cover immense areas. On the other hand vast
quantities of fossil fuels are burnt to produce the electricity (at
only 10% efficiency) to power the railways.

Trains typically use diesel, not electricity (subways & the monorail
at Disneyland not included).

However, if you're going to make up facts to support your position, I
would suggest you pretend that trains are fueled by burning Sequoia
redwoods and American flags, and all the conductors weigh 300+
pounds. These would operate at -25% efficiency, and would make your
argument even stronger.

On 14 Aug, 20:13, Darryl wrote:
On Aug 13, 1:54 pm, Nelson wrote:

altitude their shadows cover immense areas. On the other hand vast
quantities of fossil fuels are burnt to produce the electricity (at
only 10% efficiency) to power the railways.

Trains typically use diesel, not electricity (subways & the monorail
at Disneyland not included).

However, if you're going to make up facts to support your position, I
would suggest you pretend that trains are fueled by burning Sequoia
redwoods and American flags, and all the conductors weigh 300+
pounds. These would operate at -25% efficiency, and would make your
argument even stronger.

No need to invent facts look at the web site:-
http://www.bts.gov/publications/nati..._statistics/ht...
able_04_20.html

In 2001 long haul flights 3,965 Btu per passenger mile
In 2001 Amtrack 2100 Btu per passenger mile but does not
include laying and maintaining track, signals etc.

And that is of course why air travel is so much cheaper. QED

"Nelson" wrote in message
ps.com...
On 14 Aug, 20:13, Darryl wrote:
On Aug 13, 1:54 pm, Nelson wrote:

altitude their shadows cover immense areas. On the other hand vast
quantities of fossil fuels are burnt to produce the electricity (at
only 10% efficiency) to power the railways.

Trains typically use diesel, not electricity (subways & the monorail
at Disneyland not included).

However, if you're going to make up facts to support your position, I
would suggest you pretend that trains are fueled by burning Sequoia
redwoods and American flags, and all the conductors weigh 300+
pounds. These would operate at -25% efficiency, and would make your
argument even stronger.

No need to invent facts look at the web site:-
http://www.bts.gov/publications/nati..._statistics/ht...
able_04_20.html

In 2001 long haul flights 3,965 Btu per passenger mile
In 2001 Amtrack 2100 Btu per passenger mile but does not
include laying and maintaining track, signals etc.

Though Amtrack doesn't exactly run the world most passenger
efficient railway, does it?

tim

"Darryl" wrote in message
oups.com...
On Aug 13, 1:54 pm, Nelson wrote:
altitude their shadows cover immense areas. On the other hand vast
quantities of fossil fuels are burnt to produce the electricity (at
only 10% efficiency) to power the railways.

Trains typically use diesel, not electricity (subways & the monorail
at Disneyland not included).

Ummm...hate to break it to you, but the vast majority of
railroad engines these days are of the Diesel-ELECTRIC
variety - wherein Diesel fuel (a "fossil fuel") is burned to
make electricity which then makes da wheels go 'round.
And that, pretty much, is what the original comment said,
no?

Those which aren't of the Diesel-electric type would
commonly be straight electrics, picking their power up
from the grid, in which case it's a question of whatever
your nation/region uses to make its electricity in general.

Bob M.

On Tue, 14 Aug 2007 13:03:53 -0700, Nelson wrote:

No need to invent facts look at the web site:-
http://www.bts.gov/publications/nati..._statistics/ht...
able_04_20.html

In 2001 long haul flights 3,965 Btu per passenger mile
In 2001 Amtrack 2100 Btu per passenger mile but does not
include laying and maintaining track, signals etc.

And that is of course why air travel is so much cheaper. QED

Is there no maintenance or infrastructure cost to running aircraft then?

DaveM

On Aug 14, 3:12 am, mrtravel wrote:
Randy Hudson wrote:
In article .com,
Nelson wrote:

Aircraft leave vapour trails which aid in the reflection of
the sun's radiation back into space.

A study of the no-fly period following 9/11 showed a full extra degree
(Celsius) of cooling over the US during those four days, apparently due to
the lack of contrail vapor, which contributes to the cirrus cloud layer that
reflects nighttime longwave radiation back to earth.

Can you cite a source for this report showing the entire US dropped
exactly one degree Celsius and that was directly attributable to the
reduction in aircraft?

I can't find a useful reference through google, but I do agree with
Randy's
post; I remember seeing the same thing in the press. The scientists
thought this was a once-in-a-lifetime chance to study the difference
between temp patterns with normal aviation activity and with all
the planes grounded, and, IIRC, the US was cooler than the
preceding few days. Since it's a single data-point observation,
I can understand your skepticism.

UPDATE: I did find a useful link through slashdot:
http://www.wired.com/science/discove.../2002/05/52512

Cheers,

KevinB

James Robinson wrote:
mrtravel wrote:


Randy Hudson wrote:


Nelson wrote:


Aircraft leave vapour trails which aid in the reflection of
the sun's radiation back into space.

A study of the no-fly period following 9/11 showed a full extra
degree (Celsius) of cooling over the US during those four days,
apparently due to the lack of contrail vapor, which contributes to
the cirrus cloud layer that reflects nighttime longwave radiation
back to earth.

Can you cite a source for this report showing the entire US dropped
exactly one degree Celsius and that was directly attributable to the
reduction in aircraft?


Here's one article on the effect:

http://www.sciencenews.org/articles/20020511/fob1.asp

There are lots of other examples.

Maybe I misunderstood. I thought your post was indicating the
temperature was 1 degeee (Celsius) cooler. What the article says is that
the DTR (difference between the high and low temperatures) was one
degree WIDER. The article doesn't say it was 1 degree cooler, only that
the difference between high and low temperatures increased by one
degree. In fact, the report claims the temperatures increased due to
lack of contrails. "—areas of the country typically blanketed with
aircraft contrails in mid-September—showed the largest changes in
diurnal temperature range, mostly from increased daytime high temperatures"

Please explain your "extra degree of cooling"?
Contrails WARM the surface of the earth, according to the article.

The 1 degree WIDER DTR, according to the article, was due to HIGHER high
temperatures, not lower low ones. This seems contrary to your report
that there was an extra degree of cooling.

Darryl wrote:
On Aug 13, 1:54 pm, Nelson wrote:

altitude their shadows cover immense areas. On the other hand vast
quantities of fossil fuels are burnt to produce the electricity (at
only 10% efficiency) to power the railways.


Trains typically use diesel, not electricity (subways & the monorail
at Disneyland not included).

Well, quite a few of them use diesel to create electricity, hence the
name diesel-electric.