Monica Deming of the Oklahoma Climatological Survey was our next presenter at the Climate Change workshop. We notice extreme events, such as Oklahoma having a winter temperature of 27 F below zero in winter 2011 (near Nowata) but the next summer, 20121, was the hottest summer on record in Oklahoma or for any state ever. We can be fairly confident that global warming will bring more extreme events. As I wrote in my book Green Planet: How Plants Keep the Earth Alive (still available!), global warming is "stirring the climate pot more vigorously." I'm no expert but I hope this metaphor is useful.
Then
Monica explained the basics of global warming and the Milankovitch cycle. Danny
Mattox then acted it out--the first time I have ever seen anyone attempt this!
He played the Earth, revolving around Monica (the sun) at various tilts and
distances.
Monica
summarized the latest conclusions of the IPCC, including their most current
projections. There are about 25,000 indicators that Earth is becoming warmer,
everything from thermal expansion of ocean waters to melting ice to direct
temperature measurements. She gave us more information about these
measurements, e.g. that Arctic sea ice as melted much faster even than
scientists had recently predicted. Unfortunately, the world is continuing on
the path of the maximum predicted warming. At this rate, the heat wave of 2012
will not just seem normal, but seem cool, by 2090. Yes, it got up to 120 F in
parts of Oklahoma in 1936, but the scientific projections are that the number
of summer days exceeding 100 F each year will increase, to perhaps 120 days a year by the end of the
century.
And now
for something different. Instead of listening to talking heads, no matter how
interesting they are, the participants will get on computers and actually work
with climatological data, under the guidance of Brad Illston, a research
associate at Oklahoma Mesonet, a service provided by the Oklahoma Climatological Survey.
This is one of the finest repositories of meteorological information in the
country. No other state, as far as I know, has as much data so easily
accessible in such a visual format.
Mark
Twain referred to "lies, damned lies, and statistics." Statistics can
be abused. Brad explained how to use them honestly. But even when used
honestly, statistics can be misleading. Averages can be misleading, even if
honest. I recall hearing of an old Kansas farmer who said, "In fifty years
of farming, I've only seen two average years." So it helps to use not just
averages but also some estimate of variability as the standard deviation. If most of the years had been close to average,
that Kansas farmer would have seen a small standard deviation. Oklahoma City and
San Diego have the same average annual temperature, but the temperatures in OKC
are much more variable, a fact constantly confirmed by exchanges of text
messages between me and my La Jolla sister. A storm passed through San Diego
last week, and my sister texted me, the storm uprooted a tree! But this sounds like
an ordinary summer day in Oklahoma.
Another
example of being confused by statistics is, what do we mean by a hundred-year
flood? It means that, every year, there is a one percent chance of it
occurring. It does not mean such floods occur every hundred years, on the dot.
As it turns out, the odds of at least one such flood occurring in 100 years is
not 100 percent, but 63.4 percent.
The
participants then went to the computers to access and use some real Mesonet
data. The data are very user-friendly. You can easily graph annual changes in
temperature for any year, or for many years on the same graph. Just by looking
at the graph, you can see that winter is the season that has the most
year-to-year variability (or even day-to-day variability) in Oklahoma. Also,
you can access a beautiful color map that indicates soil moisture in August
2011, during a severe drought. Not all of Oklahoma was experiencing a drought;
you can see which areas were very dry compared to a long-term average (in red)
or wetter than normal (in green). The map is mostly red, but there are green
spots. The Oklahoma Mesonet therefore not only makes available a great deal of
data in a very organized fashion, but you can construct almost any graph that
you might want.
It
occurred to me that weather disasters can also test our altruism. If every
community along a river builds levees, in an understandable desire to protect
their own properties, then there will be a much greater volume of water running
downstream, vastly increasing the risk that downstream levees will be
overtopped or destroyed.
I would
like to end with the same book recommendation I made last year. The Control of Nature by John McPhee documents three
examples of hubris, in which we humans think we can control nature. One of the
examples is how we are trying to force the Mississippi River to stay in its
present channel, even while we are creating conditions that will ultimately
cause it to jump its banks and create a new delta.
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