Today, we wonder how things are really
heating up. The University of Houston's College of
Engineering presents this series about the machines
that make our civilization run, and the people
whose ingenuity created them.
Legend has it that a certain
king had his advisor executed. Then he sent out a
call for a new advisor with only one arm. The old
advisor had, once too often, said to the king,
"On the other hand..."
I'm afraid many of us are like that king when it
comes to environmental issues. If you want to make
trouble at a cocktail party, just say the words
Global Warming out loud. Either the room
will heat up, or an icy chill will settle over it.
For we all too easily turn into one-armed experts
who have no way of knowing whether they're betting
on the correct arm. The issues are very complex.
But, as we argue, data accumulate. A recent
Science magazine article is based upon
yesterday's data. In fact, the new field of data
archaeology has sprung up. I'm not kidding.
Data archaeologists have gone back into dusty files
to find rat-gnawed, mildewed files of
ocean-temperature data -- all the way back to 1950.
Those data cast remarkable light on the question of
global warming.
One issue dogs the question as to whether global
warming is really occurring. It's the fact that
warming first occurs in the ocean. Only over time
will that energy feed back into the atmosphere. The
heat capacity of the oceans is over a
thousand times that of the atmosphere. The
ocean clearly must dominate the problem. Energy
held in the ocean today is what will determine
atmospheric warming tomorrow.
We have far richer records of temperatures in the
atmosphere than in the ocean. Yet many
oceanographers have, over the years, here and
there, dropped temperature sensors down into the
water.
Once assembled, those data tell a new story. It is
that the ocean passes energy around. Much of it is
stored fairly far down where we don't see it right
away. But the overall trend is well-defined. Since
1950, the average ocean temperature has risen in a saw-tooth
fashion. Today's oceans hold about sixty
trillion megawatt-hours more energy than they did
half a century ago.
These new numbers are now evoking new estimates of
earth's atmospheric temperature by the end of the
century. Anti-greenhouse people had previously
thought it would rise as little as two degrees
Fahrenheit. Others had expected as many as eight
degrees. The new data now point toward a five- or
six-degree rise.
All this clearly needs refinement, so a project is
now underway to place three thousand free-floating
temperature stations around the oceans of the
world. As new data fill the gaps, the argument will
go on, often fueled by vested interests. However,
data archaeology has, for the moment, shifted the
game away from greenhouse naysayers.
But these aren't issues for one-armed advisors. We
need scholars, not spokesmen -- intelligent people
who struggle to define their own ignorance. We need
people who are still able to say, "On the other hand."
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
