[extropy-chat] Climate skepticism patterns

Hal Finney hal at finney.org
Thu Jun 8 17:58:58 UTC 2006

Regarding the cost/benefit of global warming, here is a paper on the
topic by Richard Tol in the journal Energy Policy.  He summarizes over
100 studies which attempt to estimate that very factor in economic terms:


Now, they are actually looking at marginal costs, not total cost; that is,
the cost of an incremental change.  And they are measuring it in terms of
tons of carbon (tC), not degrees.  But the way the calculations are done,
they go from tC to degrees via climatology models, and then attempt to
estimate economic costs and benefits.  These are then discounted to the
present day via standard discount rates.

There is quite a range in the studies, but the median cost value
is $14/tC.  That's not super high, compared to estimated costs of
conservation, but it does mean that global warming is a net cost.
The article notes that the greater impacts occur in the Third World,
particularly Africa and southeast Asia.  It also appears that slight
warming, on the order of 1 degree C, could actually be beneficial,
while larger changes are harmful.

So global warming will be harmful, at least under a current "best guess"
of 3 degrees C.  (This value is based on the assumptions that we will
roughly double the preindustrial 280 ppm even with strict emission
controls, and that climate sensitivity to a doubling is 3 C - see

At the same time, the costs of conservation are very high.  The
realclimate.org blog exists largely to oppose global warming nay-sayers,
so they are credible when they admit the high costs of emimssions
reductions.  They recently commented, "Compliance with Kyoto, a mere 5%
reduction in Narbon emissions, was forecast by Nordhaus [2001] to cost
a few percent of GDP globally. The cost to stop emission completely and
immediately may not even be calculable."


Global GDP is $44 trillion so we are talking about a cost of a trillion
dollars a year to comply with Kyoto, yet there is widespread consensus
that this modest 5% reduction will have essentially no effect on global
temperatures; it will be lost in the noise.  For a trillion dollars
a year, we gain nothing.  Compare that to costs of the technological
mitigations presented earlier, more like a billion dollars a year to
stop and reverse warming.  They are over a thousand times more efficient.

>From what I can see, emissions reductions do not make economic sense
at this time.  The costs of substantial reductions are enormous, and
there are a number of strategies on the table (ocean fertilization,
planting forests, stratospheric aerosols, space shields, exotic nanotech
and biotech engineering) which should be able to do the job cheaper,
well before the end of this century.

One final point.  I haven't yet seen Al Gore's global warming movie,
An Inconvenient Truth.  However I'll note that the title is somewhat
misleading, as the "truth" that he presents is actually quite convenient
for supporters of centralization, world government, economic controls,
and collective action - in short, for leftists, and for Al Gore himself.

Listening to a TV review of the movie, they quoted Gore as saying
that within 10 years we will reach a tipping point, and if we don't do
something by then we are doomed to very bad consequences.  This is his
"inconvenient truth".  But listen to what Science magazine wrote a few
weeks ago:

> A central feature of this long baseline is this: At no time in at
> least the past 10 million years has the atmospheric concentration
> of CO2 exceeded the present value of 380 ppmv. At this time in the
> Miocene, there were no major ice sheets in Greenland, sea level was
> several meters higher than today's (envision a very skinny Florida),
> and temperatures were several degrees higher. A more recent point of
> reference, and the subject of two papers in this issue, is the Eemian:
> the previous interglacial, about 130,000 to 120,000 years ago. This
> was a warm climate, comparable to our Holocene, during which sea levels
> were several meters higher than today's, even though CO2 concentrations
> remained much lower than today's postindustrial level.


See also http://www.sciencemag.org/sciext/ice/ for additional stories.
The point is that the actual truth is even more inconvenient than Gore
admits (from what I have read about the movie), and is inconvenient even
for the collectivists I listed above.  The truth is that the tipping point
is not ten years away, but many years in the past.  We have already put
too much carbon into the atmosphere.  Even today's level of CO2 (absent
technological mitigation) has commited us to enough sea level rise to
cover most of Florida, as well as major coastal cities.  And there is no
plausible enforcement policy which can stop CO2 level from continuing
to rise for many decades.  We are at 380 now, will pass 400 shortly,
and only with the most stringent restrictions will we be able to level
off at 500 or 550 ppm.  This commits us to far more warming, even if
everyone listens to and believes Al Gore.

The real inconvenient truth is that emissions reductions will not
stop the catastrophic consequences of global warming.  Even enormously
costly efforts will make only a small difference.  The only solution
is technology.  This is not a lesson that Al Gore is particularly eager
to teach, but it is what the world must learn in order to deal with this
problem rationally and efficiently.


P.S. I have to admit that just as Al Gore's truth is convenient for him,
my own truth is convenient for me.  I like technology and I like the
idea of a world which actively utilizes technology to manage climate
and other global issues.

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