AGW revisited -- James Randi

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AGW, Revisited
Written by James Randi
Tuesday, 15 December 2009 17:14

Though this subject is not one that directly concerns the JREF,
I'm very frequently asked if I'll turn my skeptical eye to it. As
a year-end fling, I'll give it a try. To wit:

An unfortunate fact is that scientists are just as human as the
rest of us, in that they are strongly influenced by the need to
be accepted, to kowtow to peer opinion, and to "belong" in the
scientific community. Why do I find this "unfortunate"? Because
the media and the hoi polloi increasingly depend upon and accept
ideas or principles that are proclaimed loudly enough by
academics who are often more driven by "politically correct"
survival principles than by those given them by Galileo, Newton,
Einstein, and Bohr. (Granted, it's reassuring that they're
listening to academics at all -- but how to tell the competent
from the incompetent?) Religious and other emotional convictions
drive scientists, despite what they may think their motivations
are.

The Intergovernmental Panel on Climate Change (IPCC) -- a group
of thousands of scientists in 194 countries around the world, and
recipient of the 2007 Nobel Peace Prize -- has issued several
comprehensive reports in which they indicate that they have
become convinced that "global warming" is and will be seriously
destructive to life as we know it, and that Man is the chief
cause of it. They say that there is a consensus of scientists who
believe we are headed for disaster if we do not stop burning
fossil fuels, but a growing number of prominent scientists
disagree. Meanwhile, some 32,000 scientists, 9,000 of them PhDs,
have signed The Petition Project statement proclaiming that Man
is not necessarily the chief cause of warming, that the
phenomenon may not exist at all, and that, in any case, warming
would not be disastrous.

Happily, science does not depend on consensus. Conclusions are
either reached or not, but only after an analysis of evidence as
found in nature. It's often been said that once a conclusion is
reached, proper scientists set about trying to prove themselves
wrong. Failing in that, they arrive at a statement that appears
-- based on all available data -- to describe a limited aspect
about how the world appears to work. And not all scientists are
willing to follow this path. My most excellent friend Martin
Gardner once asked a parapsychologist just what sort of evidence
would convince him he had erred in coming to a certain
conclusion. The parascientist replied that he could not imagine
any such situation, thus -- in my opinion -- removing him from
the ranks of the scientific discipline rather decidedly.

History supplies us with many examples where scientists were just
plain wrong about certain matters, but ultimately discovered the
truth through continued research. Science recovers from such
situations quite well, though sometimes with minor wounds.

I strongly suspect that The Petition Project may be valid. I base
this on my admittedly rudimentary knowledge of the facts about
planet Earth. This ball of hot rock and salt water spins on its
axis and rotates about the Sun with the expected regularity,
though we're aware that lunar tides, solar wind, galactic space
dust and geomagnetic storms have cooled the planet by about one
centigrade degree in the past 150 years. The myriad of influences
that act upon Earth are so many and so variable -- though not
capricious -- that I believe we simply cannot formulate an
equation into which we enter variables and come up with an
answer. A living planet will continually belch, vibrate,
fracture, and crumble a bit, and thus defeat an accurate
equation. Please note that this my amateur opinion, based on
probably insufficient data.

It appears that the Earth is warming, and has continued to warm
since the last Ice Age, which ended some 10,000 to 20,000 years
ago. But that has not been an even warming. Years of warming
followed by years of cooling have left us just a bit warmer than
before. This conclusion has been arrived at from data collected
at some 1,200+ weather stations in the USA, though bear in mind
that there are very few weather stations over the vast oceans
that cover 70% of our planet, or on the continents Africa, South
America, and especially Antarctica.

We can now record temperatures with much better than the former
fraction-of-a-degree accuracy we had just a decade ago, but that
temperature change appears to be just about half a degree
Centigrade.

Our Earth's atmosphere is approximately 80% nitrogen, 20%
oxygen. Just .04% is carbon dioxide -- a "trace" amount. But from
that tiny percentage is built all the plants we have on
Earth. CO2 is a natural molecule absolutely required for plant
life to survive, and in the process of growing, those plants give
off oxygen. We -- and all animal life -- consume that oxygen and
give off CO2. (No, this is not an example of Intelligent Design.)
If that balance is sufficiently disturbed, species either adapt
or perish. And the world turns...

Incidentally, we have a convenient phenomenon that contributes to
our survival. Doubling the amount of CO2 in our atmosphere will not
double the temperature rise, small though it is. The basic principle
of what's known as the "greenhouse effect" is quite simple: in a
glass-enclosed environment, sunlight enters through the glass and
strikes a surface, where it is transformed into longer infrared rays
which do not easily reflect back through the glass; they're trapped
and raise the temperature. However, the greenhouse effect as applied
to our planet is more complicated. The infrared rays that are
reflected back from the Earth are trapped by the greenhouse gases,
water vapor and CO2 -- a process that warms those gases and heats
the Earth. This effect makes Earth habitable, preventing extremes
of temperature. The limit of the influence of CO2 is dictated, not
by the amount of greenhouse gases in the atmosphere, but by the
amount of solar radiation reflected back from the Earth. Once all
the infrared rays have been "captured" by the greenhouse gases there
is no additional increase in carbon dioxide.

Yes, we produce CO2, by burning "fossil fuels" and by simply
breathing. And every fossil fuel produces CO2. Some products produce
more than others, varying with their chemical composition. Methane gas
produces less CO2, wood produces more. But almost paradoxically, when
wood burns it produces CO2, and when a tree dies and rots it produces
yet more CO2. Oceans are huge storage tanks for CO2, but as they warm
up, they hold less of the dissolved gas. They release it into the
atmosphere, then more of it is absorbed back into the oceans. And as
far as humans are concerned, ten times more people die each year from
the effects of cold than die from the heat. This a hugely complex set
of variables we are trying to reduce to an equation...

It's easy enough to believe that drought, floods, hurricanes, and
earthquakes are signs of a coming catastrophe from global warming, but
these are normal variations of any climate that we -- and other forms
of life -- have survived. Earth has undergone many serious changes in
climate, from the Ice Ages to periods of heavily increased plant
growth from their high levels of CO2, yet the biosphere has
survived. We're adaptable, stubborn, and persistent -- and we have
what other life forms don't have: we can manipulate our
environment. Show me an Inuit who can survive in his habitat without
warm clothing... Humans will continue to infest Earth because we're
smart.

In my amateur opinion, more attention to disease control, better
hygienic conditions for food production and clean water supplies, as
well as controlling the filth that we breathe from fossil fuel use,
are problems that should distract us from fretting about baking in
Global Warming. From Sir Arthur Conan Doyle's 1891 A Scandal in
Bohemia, I quote:

Watson: "This is indeed a mystery," I remarked. "What do you
imagine that it means?"

Holmes: I have no data yet. It is a capital mistake to theorise
before one has data. Insensibly one begins to twist facts
to suit theories, instead of theories to suit facts...
.

Relevant Pages

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