Yay,
bush
Peg: “It WOULD be nice to give GWB a plug for
something he did quite well. I’m talking about his home that is
conservation in action. Here
is a link to the snopes post about it.”
☞
Kudos to him for his energy-efficient Crawford house. The reader may supply
his or her own devastatingly caustic follow-on line.
TRIANA’S
MEDS
Clare
D.:
“Triana mentions
Procrit and Advair. There is a generic for Advair. There is not one for
Procrit, but it’s a relatively new drug which has to be injected.
I’d be curious if appeals could not be made to the manufacturer for mercy
dosage. I would hope that any med bill would include some way for people to
easily check for themselves, the generics and the efficacy of various new
drugs. Relying on doctors to do so is foolish in this day and age; doctors
are encouraged to prescribe expensive drugs. Even doctors at Kaiser Permanente,
I’m sure. Drug companies try to fool you: Caduet is the (more expensive,
in-patent) version of Lipitor plus Norvasc. Norvasc has a generic
equivalent and Lipitor has a similar generic, non-equivalent. Arthrotec
is two generics combined into a non-generic one, the better to charge you
more. With age, I’ve gone from essentially no pills to many for me and
equally as many for my demented husband. Since I’m NOT demented, I
have to keep track of them for both of us and stay as far short of the donut
hole as possible. I have to be constantly on guard. Not all doctors are
interested in saving money for their patients and frequently they just
don’t KNOW the costs! I’ve learned that a lot of times the
people who want to keep their aged parents on expensive drugs, at the expense
of anyone BUT themselves, are people who have trouble with the idea of parents
dying.”
☞
Leaving aside that most people have trouble with the idea of their
parents’ dying, there’s a lot to what Clare says.
white
DRIVEWAYS
Worried
about your carbon footprint? Instead of buying a new, more fuel efficient
car for $30,000, you might consider buying a case of “striping
spray paint” for $56. In the first place, you save the cost to
the environment of MAKING a new car (you think energy and chemicals and carbon
emissions don’t go into THAT?). And in the second, by my calculations,
in this example, you save $29,944.
I got this idea from my old pal Richard Factor, who got it from thinking about
the carbon footprint of his Prius. Even a Prius sends CO2 into the
air. He says you should paint your driveway white.
“Making
roads and roofs a paler color could have the equivalent effect of taking every
car in the world off the road for 11 years,” Energy Secretary Steven Chu
has said.
And really, that pretty well sums up the
concept, for us laymen. White stuff reflects radiation, black stuff absorbs
it. Whether you’re a guy out in the desert or a little planet called
Earth, white is the cooler of choice.
You could stop reading there, but
Richard summarizes his lengthier, calculation-ridden article
here:
If you like to drive, or, for that matter, breathe, you
may find it difficult to reduce your CO2 output. I cut mine in half, at
least as far as driving is concerned, by buying a Prius hybrid. But still
it’s only in half. What if I’m a serious believer in the
threat, and want to reduce it to zero? No problem! There are
organizations that sell “offsets.” While most human
activities create more carbon dioxide, some reduce it.
Planting trees, increasing energy efficiency, “sequestering” CO2
underground – all reduce its atmospheric burden. These
organizations accomplish it in various ways. You accomplish it by –
surprise! – sending them money.
Ø Why
Did The Chicken Cross the Road?
The road, in this case, is the kind of road you are likely to
find in front of your house. It’s two lanes, separated by a yellow
or double-yellow line down the center and two white “fog lines”
demarking its edges. It’s paved with asphalt, often called
“black top” because — let’s not always see the same
hands — it’s black. The chicken crossed because once
he stepped on it his feet got very hot, and, even with a brief respite gained
by pausing at the yellow lines, he wanted to get to the other side and cool
them off. Clever chicken! I made the same discovery one day when
the shoe police were unaccountably preoccupied and thought to myself “If
they made roads like this in ‘inverse video’ there would be a lot
less heat absorbed by the planet.”
A quick Google search located a carbon footprint calculator,
which in turn yielded the amount of money I would have to spend to compensate
for the CO2 spewing forth from my Prius every year. It was about
$45. I would have sent them a check right away, but that would mean
they’d have 45 of my dollars and I wouldn’t. Instead I
thought of an experiment. The global warming problem is (allegedly)
occurring because CO2, a major culprit in the greenhouse effect, is causing
solar radiation that would otherwise escape back into space to remain here and
warm the planet. How about if I were to keep the $45, and instead put
a mirror someplace where it would send that nasty radiation back to the sun?
Although I don’t have a mirror, and may not have any good place to put it
without complaints about the glare, I can at least think about it, right?
How much CO2 does my Prius emit on an annual basis?
Easy! I know I used 425.2 gallons of gas during calendar 2006, thanks to
my trusty spreadsheet. At 19.4 pounds per gallon, that’s 4.12 tons
of carbon dioxide.
How much energy have I gotten from this gas? Each gallon
contains 121MJ (Megajoule or million watt-seconds) which is the equivalent of
121,000,000/(3600*1000) = 33.6 kilowatt hours. (Although I haven’t
“gotten” all this energy to move my car, one way or the other it
has been added to the environment.) Thus, to make my car “energy
neutral,” I have to somehow compensate for those tons of carbon dioxide
and, although it is rarely mentioned as a problem, the energy I have added to
the environment as well.
I was about to perform a long calculation here about how much
energy the sun deposits on the earth, but I was saved the trouble. Quoting
from the source:
Solar power per m2 on
U.S. surface … this seems a little low … it’s 1342 watts per
m2 outside the atmosphere, about 1000 watts per m2 at
high noon on the ground, and on average (day and night) about 240 watts per
meter2 absorbed at the ground. This is the average over the Earth
too.
I’m going to assume that “absorbed at the
ground” implies an albedo (reflectance) of zero. I’m also
going to assume that 240 watt figure is correct for my location: At the
equator it would be higher, at the poles it would be lower. At
mid-latitude, it’s probably close enough. If I want to get rid of
the energy I have added to the earth’s environment, all I have to do is
radiate 452.2*33.6kWh of energy back into space. This is 15,194kWh and
there are 8,760 hours in a year. Although I can’t redo the roads in
inverse video, I can dump 240 watt-hours per hour per square meter back into
space by putting a mirror over a black spot on my own driveway. I
calculate that a mirror of about 20.6 square metres, or 14.7 feet on a side
would be sufficient.
Ø Mirrors
and Albedo
After estimating the mirror size I realize that it’s not
entirely practical. Not that I can’t find a 14.7 foot square spot
to put it, but rather that I would have to send money to somebody else
to get the mirror. But all is not lost! A clean mirror will have an
albedo as close to 1 as matters. “Worn asphalt” as is present
on my driveway and many others, has an albedo of .12. It seems entirely
possible to achieve the albedo of “fresh snow” (.8-.9)
artificially. Striping paint should do the job, and on a driveway
it will get little wear and so stay clean and reflective. Re-estimating
how much area would need to be raised from an albedo of .12 to .8 instead of
the hypothetical effectiveness of the mirror (from 0 to 1), I come up with
about 30 square meters instead of 20. I took a quick look at eBay
(pay list for striping paint? Are you nuts?) and found that at
least one seller had spray cans available, six for $15. These
would be enough to cover almost 40 square meters, so if one has the
space, clearly the cost isn’t prohibitive. So far so good.
But this isn’t the whole story. Striping the 30
square meters “remediates” the energy used driving the car.
What about the accumulation of carbon dioxide?
Ø The
CO2 Question
Unlike the heat created by burning gasoline, CO2 doesn’t
create heat at all. Rather, it can be viewed as amplifying sunlight.
Instead of warming the earth directly, it allows the sun to warm the earth more
than it otherwise would by preventing infrared radiation from escaping into
space. Where does this infrared radiation come from? The sun emits
radiation, both infrared and visible. Much of this energy is contained in
the visible range. The visible light is converted to infrared when it is
absorbed. In principle, therefore, painting more of the driveway
white, which will reflect the visible light and hence energy into space, will
reduce the amount of infrared that is available to be absorbed.
There is a conceptual problem with this, however. Painting
a fixed portion of the driveway compensates for the annual component of
the car’s energy use. As long as I continue to commute, that white
patch I hypothetically painted a few paragraphs ago will remediate my heating
the planet. However, the CO2 production is cumulative.
Every year I add more to the atmosphere. While there are various
(complicated) processes of equilibration, they typically exceed the life of the
car and perhaps the life of the human driving it. Therefore, I would have
to add more white paint every year to compensate for the cumulative addition of
carbon dioxide to the atmosphere. Will I run out of driveway before I
die?
Ø Energy
Balance
Unlike the energy-reflection calculation which is theoretically
simple, calculating how much energy I have to reflect to compensate for that
added by my 4.12 annual tons of CO2 is fraught with uncertainty. There
are already a number of IR-absorbing gases in the atmosphere, including water
vapor, methane, and all the CO2 that’s already there. All these
gases absorb IR at different altitudes and at different frequencies, some of
which overlap.
Wikipedia says that the present concentration of CO2 has a radiative forcing of
1.5W/m2. Right now the CO2 concentration in the atmosphere is
380ppm. Back in 1980 it was 340ppm. Although the forcing
isn’t a linear function of concentration, it’s probably close to
linear over a small interval, so it should be fair to say that the annual
increase in forcing in a given year is [(2006-1980)/(380-340)]*(1.5/380).
That equals .0026W/m2 per year. Assuming that’s a day and night
average, and using 5.2*1014m2 for the surface area, we
get 1.35*1012 (1.35 terawatt) increase (per year) of excess
power added by CO2. For every year that I drive, I have to reflect my
share of that 1.35TW back to space, along with all the 1.35TW fractional shares
from previous years as well, or 1.9MWh the first year, 3.8 the next, etc.
Two conclusions: First, if I decide to remediate the CO2 I
may eventually run out of driveway and perhaps I will have to move.
Second, one shouldn’t ignore the annual contribution of energy from fuel
burning since it is the equivalent of several years of CO2 emission, even if
it’s far less than the CO2 cumulative contribution. If
anything, this would seem to be a splendid argument for being less profligate
regardless of our energy source.
Ø My
Tom Sawyer Moment
If you have read this far, you may well have come to the
conclusion that I’m a climate nut, übergreenie, environmentalist, or
someone who embodies great and perhaps excessive angst over the environment,
global warming, and, for all I know, beryllium dust from nuclear fission
weapons. I am none of the above. In fact, this article, with its
interesting and, I hope, arithmetically-reasonable conclusion, was engendered
only by the question first posed: “How big a mirror?”
But if you wonder why there is so much argument and conflict on the issue of
global warming, just take a close look at the error bars in the enlarged
“Radiative
Forcing Components” chart.
As far as painting the driveway is concerned, I’m not
going to do it.
And there’s a simple, practical reason:
If the driveway is black, the snow melts faster. I’m
hoping that by showing how cheap white striping paint can be, somebody else
will paint his own driveway. Preferably someone in the South,
where even more energy will be reflected, and where he won’t have to deal
with snow that refuses to melt as a consequence.
Any volunteers?
(Subsequent to my three-part
blog on this subject, of which this is a
diagram-free and (mostly) calculation-free summary, a paper “White
Roofs Cool the World, Offset CO2, and Delay Global Warming,” came to similar conclusions, although they
considered roofs rather than driveways. The authors are real
scientists. If you don’t believe me and are too busy to read their
summary, just note the following: Their address for further inquiry is
“One Cyclotron Road.”)
© 2009 Richard Factor
☞ “But Richard,” I asked, my albedo
strangely aroused by his analysis, “once the snow is on the driveway, the
driveway is WHITE. No?”
No! [he responded] I can tell you’ve never
tended a driveway during a northern winter. Of course you are correct if a
major snow has JUST fallen. But you don’t leave it there, you shovel
away (or person the snowblower) until the top layer is off to the side. At
this point, depending on any number of pre- and post-snowfall weather
conditions, you can be left with anything from an almost dry and completely
usable driveway to an impenetrable layer of ice. In turn, the ice may be
verging on transparent with the blacktop tantalizingly visible beneath, or it
may be mottled and chunky. In any case, the ice is difficult to remove.
If transparent, the black driveway underneath will
absorb enough sunlight to make a thin liquid layer under the ice, which turns
shoveling from a frustrating experience to a pleasant session with the MP3
player. If the ice is less cooperative, you can still make enormous progress
by chipping away a few areas and letting the sunlight melt the margins. This
requires numerous trips to the driveway, but progress is much more rapid.
Given the variability of the wind, insolation,
temperature, humidity, etc., it’s difficult to know in advance when the
sun will help or be irrelevant. But - “trust me” - it’s a
big help often enough that I’m willing to sacrifice a nanodegree of
warming (or not-cooling) to have that advantage. If my driveway were flat, I
might feel otherwise, but I live in hill country and the driveway with its few
degrees of tilt occasionally traps even the 4WD Ford Escape (hybrid, of
course). The Prius? Forget it!
