Saturday
morning, after a good cafeteria breakfast (the OU Biological Station is famous
for its food), and everyone is in a good mood to start the first full day of
the climate change workshop sponsored by Oklahomans for Excellence in Science
Education (OESE) and the Oklahoma Climatological Survey. About 20 middle school
and high school teachers are participating.
Danny
Mattox, a middle school educator, explained how different proxies, such as
carbon and oxygen isotopes, can be used to reconstruct past climate. For
example, water with the light isotope of oxygen evaporates faster than water
with the heavy isotope; therefore during periods of glaciation, water with the
light isotope gets removed from the oceans and deposited in glaciers. Ancient
ice enriched in the light isotope, or foram shells enriched in the heavy
isotope, are indicators of global temperature thousands or millions of years
ago. Pollen is also a proxy for climate, since you can distinguish the pollen
of plants that grow in cool or moist conditions from pollen of plants that grow
in hot or dry conditions.
Then he
provided evidence, from his own research, that the Trail of Tears (in
particular, the Choctaw Removal) occurred during an unusually cold climate
period, based on many independent but convergent climate proxies. This cold period was due to
such things as an unusually high number of volcanic eruptions, an El Nino
event, and a period of low solar radiation. This caused a very cold winter and
contributed to the massive deaths of Natives--weather making an already cruel
act perpetrated by the U.S. government even worse.
The next
presenter was Alek Krautmann from the Southern Impact Climate Planning Program.
Oklahoma has the most weather disaster events relative to the size of the
state. Because strong and destructive storms are related to higher
temperatures, this situation is nearly inevitable to become worse. This is in
addition to the fact that we now have more suburbs, therefore human structures
and investment are spread out over more area, susceptible to storm damage. From
the NOAA list of billion-dollar disasters, the worst was Hurricane Katrina of
2005. The fact that Katrina was a "category 5" storm offshore and
category 3 when it hit land near New Orleans does not tell you all of the
interacting disasters that occurred: not just the storm, but levee failure and
the breakdown in emergency response, especially when hundreds of thousands of
people fled northward from the storm. Earlier storms were less economically
destructive because now there is so much coastal development.
This year
(2014) seemed pretty mild to us because there were fewer and smaller Atlantic
hurricanes; but it was a violent year in the Pacific.
But
another source of billion-dollar disasters is drought. Katrina caused $125
billion of damage, and Sandy cost $65 billion, but the 2012 drought caused $30
billion of damage. Droughts may also become more severe and frequent with
global warming. Droughts can be measured in different ways; for example, how
much agricultural loss occurs, or how much stream flow is lost, or the
disparity between supply and demand for human use. In the 1950s drought, Dallas
ran out of good water; they had to use brackish water, unless you had a special
card to show that you had kidney problems and needed clean water. Texas has had
about 40 years of above-normal precipitation, so they were surprised when the
ongoing severe drought began in 2011.
The
impacts of drought can be very complex; low levels of warm water caused massive
"blooms" of harmful "algae" (including cyanobacteria) in
Oklahoma and other areas in 2011 and 2012. Though rain has returned to
Oklahoma, nearly every reservoir remains low, something that many of us could
see by driving to this meeting. Drought
and heat interact: it takes more water to raise corn when it is hot than when
it is a little cooler. You can get current and recent historical U. S. drought
information at http://www.drought.gov.
The average
rainfall value means almost nothing; what determines the health of humans and
nature is determined by departures from this value, especially multi-year droughts.
We also
discussed how we sometimes fail to notice drought because we draw water out of
aquifers, which were charged with water mostly at the end of the last ice age.
But even here, people are becoming more aware of our water limitations. Texas
County, Oklahoma, uses a prodigious amount of water from the Ogalalla Aquifer
to raise corn, but this year some of us have noticed that they are not raising
as much corn as they used to, perhaps because in the last couple of years the
farmers have had to drill over fifty feet deeper just to find irrigation water.
We need
scientific measures and explanations to help people understand what is
happening with drought. Brad told us about the "Hydro-illogical
cycle," which consists of: Rain; apathy; drought; concern; panic; then the
rain returns, leading again to apathy.
We must
also be careful about the use of statistics. For example, considering a map
showing the cumulative number of tornadoes may be biased, since small tornadoes
out in the country may go unreported, while they all get reported from urban
areas where there are lots of people to observe them and be affected by them.
And should we count straight-line wind damage in with tornado damage?
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