Re: Global warming, population, nuclear power

Jim Whitehead (
Thu, 1 May 1997 13:18:33 -0700

>Ron wrote:
>>Gordon wrote:
>>>Jim wrote:
>>>>Solar doesn't
>>>>cut it -- we already use more energy in a year than falls as sunlight in a
>>>Even at 10% efficiency, 1 thousandth of the Earth's surface should
>>>thus be able to provide sufficient energy for all current needs.
>>As suspicious as Jim's initial claim was (solar is not enough),
>>this sounds equally unlikely (1/1000 is enough).
>As a scientist, I don't give a damn for the far-out claims of the
>new-age "enviromentalist" religion that seems to have become
>mainstream in 1989. I might give a damn if the believers could point
>to statistically significant effects (unlike the "evidence" for global

In other words, I don't believe you, and for want of any better ammunition,
I'll make attacks on your sources. Very scientific. All you've done is
attack one assertion I made which I couldn't back up, and now you're
throwing out the entire argument?

BTW, a complete list of the people who helped draft one of the most
influential "religious" documents about climate change, the
Intergovernmental Panel on Climate Change, created by the United Nations
Environmental Program, UNEP, can be found at

And the report these authors contributed to is at:

The large number of contributors from many regions of the Earth should
convince you this isn't just another cabal of left-wing American academics.

>, avoid extrapolation many decades in advance (sometime around
>1850 it was confidently predicted that given the rate of increase of
>the horse population, Britain would be 6 feet deep in horse-shit by
>1950), avoid reliance on "computer models" (which give random numbers
>for output, which contradict each other and which are only reported
>when they fit the dogma) etc, etc.

The argument can be made looking at existing data. CO2 levels are now
appx. 100 ppm higher than before industrialization. There has been
research which shows that current temperature levels on Earth are higher
than they would be in the absense of greenhouse gasses (i.e., something is
keeping more energy on Earth than analysis of incident energy less
reflected and radiated out energy would account for). Venus also provides
evidence that CO2 acts as a greenhouse gas. So, if you have increasing
levels of atmospheric CO2, and you know CO2 acts as a greenhouse gas, what
is the expected result on the system?

You can make the argument of "we won't know until we have more data," but
this is like saying, "if I drop a computer from a rooftop, I won't really
know what happens to it until I run the experiment." Yes, the earth is a
vastly more complicated system than a simple 2 body problem, but it still
seems to me that if you add CO2 to a planetary system, and continue to add
CO2 to that system, the result will be an increase in the heat stored by
that system.

Corroboration of the increase in anthopogenic CO2 production is given by:

The last two figures are part of a lecture/report at:

Unfortunately the attribution for the figures isn't enough to trace them
back to primary sources, but I saw these two figures in the talk by Dr.
Hansen, so I suspect they're not bogus either.

Radiative forcing function figures are provided by the IPCC report, which
gives radiative forcing figures of all greenhouse gasses at 2.45 watt/m^2,
which is due primarily to CO2 (1.56 W/m^2), CH4 (0.47 W/m^2), and N20 (0.14
W/m^2). These figures can be found at:

>It's worse than medieval fanaticism... no thought required! In fact
>avoid thinking or you'll realise how bogus it is! Science is your
>enemy! Basic numeracy is most definitely not needed!

But of course, these are just the rantings of a religious cult which
includes scientists from all around the world. :-)

>For example the claim above. I burst out laughing at it. Gordon's
>reply is correct, in fact he was using conservative estimates. The
>solar power incident on the atmosphere is 35 megawatts per capita or
>so as he said, of which about half reaches the ground (or ocean).
>This is as much as a small nuclear plant delivers. Gordon estimated
>his power consumption at 10 kilowatts max. Actually an American uses
>3 kilowatts average but Americans are by far the most greedy per
>capita. An average human consumes about .6 kilowatts. I'm including
>industry, cars and so on of course.

OK, I'll back off my initial claim that humans use more energy than hits
the earth from the sun (this was based on my recollection of a slide shown
in Joel Cohen's talk, and I'll admit my memory could be faulty on this
score). However, there have been articles published which state that U.S.
Energy needs could not be satisfied by solar power alone, which is the
point I had intended to make.

In [1] (1991) it is reported that, "With a self-sustaining solar energy
system replacing our current dependence on fossil energy, the energy
availability would be one-fifth to one-half the current level. Then if the
U.S. population remained at its current level of 246 million, a significant
reduction in our current standard of living would follow, ... even if all
the energy conservation measures known today were adopted. If, however,
the U.S. population wishes to continue its current high level of energy use
and standard of living and prosperity, then its ideal population should be
targeted 40-100 million people..."

Another study [2] (1994), reported that if Americans cut their energy use
in half, and had a population of 200 million, and recycle resources
effectively, then their energy needs could be satisfied by capturing all
the solar energy incident on about 900,000 square kilometers of land,
without reducing agricultural or forest production (but presumably with
negative effects on the desert ecosystem hosting the arrays), a square
appx. 948.7 kilometers on a side.

The same study (by Pimentel et al.), on p. 363, (quoted from p. 417 of [3],
and notes in brackets are from [3]) states,

"Worldwide, renewable solar energy could be developed to provide 200 quads
of sustainable energy per year, while maintaining needed agricultural and
forestry production. [A quad is one quadrillion, or 10^15, British thermal
units or 1,055 petajoules. Thirty quads equal one terawatt-year, or 10^12
watt-years. For comparison, total worldwide commercial energy production
in 1989 was approximately 295 quads, of which a bit over 7 quads was
primary electricity from geothermal, wind and hydro sources. World
Resource Institute 1992, p. 314, reported 1989 total commercial energy
production as 310,972 petajoules, geothermal and wind primary electricity
as 141 petajoules, hydroelectricity as 7,539 petajoules. Thus Pimental et
al. assumed less future solar energy than the total currently derived
largely from fossil sources, but much more solar energy than is currently
used to produce primary electricity.] That combined with active
conservation efforts, a satisfactory standard of living would be possible
for everyone. However, the human population would have to be much smaller
than the present 5.5 billion."

[1] D. Pimentel, M. Pimentel, "Land, energy and water: The constraints
governing ideal U.S. population size." Focus: Carrying Capacity
Selections, Vol 1., No. 1, Spring 1991, p. 9-14.

[2] D. Pimentel, R. Harmann, M. Pacenza, J. Pecarsky, M. Pimentel.
"Natural resources and an optimum human population," Population and
Environment: A Journal of Interdisciplinary Studies, Vol. 15, No. 5, May,
1994, p. 347-369.

[3] J. Cohen, "How Many People Can the Earth Support." W.W. Norton & Co.,
New York, 1995.

Now, my initial assertion was couched in terms of trading off solar vs.
nuclear power to meet the energy needs of the U.S.. I personally don't
share the view of the authors above that it would be possible to a) keep
population down and b) reduce energy use. My estimate of the actual land
area required for use for solar power is appx. 2.565 million square
kilometers (multiply 285/200 (population * 900,000 then double the result).
This would presumably have a very large negative effect on the ecosystems
where the arrays were placed. Nuclear power, on the other hand, would
require significantly less area (I don't have actual figures, but I'll
estimate there are about 200 active reactors in the US, and each reactor
requires appx. 40 square kilometers, to meet appx. 20% of U.S. electricity
production. To meet all electricity production, this is a land use of
40,000 square kilometers, much much less. However, land use isn't the only
environmental impact -- nuclear waste has to be considered as well. If
recycling of nuclear waste were performed up the levels of the Integral
Fast Reactor (IFR) (See the "Unofficial IFR Home Page," hosted by the Dept.
of Nuclear Engineering at Berkeley, at then waste volume can be reduced
by a factor of 2 to a factor of 10, generate up to 200 times more
electricity from uranium ore than current reactors (the number seems high
to me, but even a 20% increase in yield would be significant), and the
final waste product is much, much less radioactive than current waste, with
halflifes of hundreds of years.

If you trade off the most advanced solar power vs. the most advanced
nuclear power, the nuclear power solution appears to meet energy needs with
less environmental impact than the solar power solution. So, if you're
looking for non CO2 emitting power sources (i.e., non-combustion sources,
which can be justified by medical reasons to reduce fine particulates, even
if you don't but the greenhouse gas argument), nuclear power seems to have
fewer drawbacks than solar power.

An interesting view of options available to policy makers developed by the
Intergovernmental Panel on Climate Change report is available at:

It discusses the tradeoffs between solar, nuclear, alternate fuels,
re-forestation, and other options.

- Jim