Bob Harriss (NCAR/ESIG)
Monday July 17, 2000
Societal Impacts
Notes by: Jessie Cherry and Arthur M. Greene, L-DEO
Introduction
Several decades ago the focus of collaborations between scientists and policy
makers was on local scales, addressing acute environmental impacts such as point-source
pollution. Most of those kind of localized environmental problems have now been
addressed, and the present set of environmental problems are more chronic and span both
larger geographic areas and longer time scales. Study of these global environmental
problems has been facilitated by the development of observing satellites, twenty-seven of
which are slated for launch over the next decade. Whether or not scientists and
policymakers will have the same success with these global-scale challenges and how we
might take effective actions utilizing new science become the questions going forward.
Harriss referred to the "inversion problem," i.e., how to translate fundamental scientific
understanding into political action. Three examples of large-scale environmental
challenges, including observing approaches and actual or potential policy responses, were
discussed. These were (1) human vulnerability to hurricanes (2) climate variability and
water supply in the US/Mexico border region, and (3) applications of remote sensing in
agriculture. Harriss concluded that appropriate coping strategies come from a free flow of
information, flexible policies, and knowledge of internal (local) and external constraints.
Lecture
(1) Hurricanes and other extreme events
A thought experiment is proposed to the audience (Fig. 1). Maloney and Hartmann
[2000] show a robust statistical correlation between the Madden-Julian Oscillation (MJO)
and frequency of occurrence of tropical cyclones in the Gulf of Mexico, this being four
times greater during the "westerly phase" of the MJO. How might such information be
employed, in economic and urban planning, agriculture, risk management or by insurance
companies? Issues include how to disseminate information, how to prevent
misinterpretations of same, how to convey the limitations of predictions.
Highest on the list of societal concerns is reducing vulnerability to extreme climate
events. Fig. 2 [Pielke 1997 as adapted from Hebert et al. 1993] shows both the dollar
value of damages and deaths caused by hurricanes in the twentieth century. Value of
damages, especially to infrastructure, has skyrocketed in recent years for several reasons.
Firstly, there is simply more infrastructure in harms way. More and more of the world's
people are concentrated in coastal areas [Fig. 3, Pielke and Pielke] a trend that is related
to population age structure and wealth. Secondly, more damages have been assigned
dollar values in today's economy. Shifting property regimes and sectors such as
insurance have changed the identity of the stakeholders for extreme weather events. On
the other hand, hurricane-related mortality has been significantly reduced, largely due to
the application of forecasting science. Fig. 4 illustrates the shrinking errors in hurricane
forecasts since mid-century. This is a nice illustration of how emergency management
has used the science.
Fig. 5 shows "Factors Contributing to Damaging Floods" [Pielke and Downton,
2000]. Flood damage is dependent on precipitation and hydrology, which may both be
affected by human impacts. Research in this area is improved immensely by recent landuse observations from the Terra satellite. Policymakers look at exposure, that is
structural and non-structural mitigation, as well as the people and property that occupy
the floodplain. The next big leap to make is to comprehensively integrate Earth system
science into policy analysis. The principal challenge to this goal is the time scale of
natural cyclone variability. Fig. 6 [Bove et al.,1998] shows Gulf landfalling Hurricanes
by decade.
An important incentive for mitigating vulnerability to Hurricanes is the sensitivity
of the Gulf economy. Forty-one percent of US oil-refining capacity sits at sea level in
Texas and Louisiana [Fig. 7]. Even the threat of a landfalling Hurricane thus has the
potential for increasing the cost of petroleum products, with consequent economic
effects. Further, evacuating the oil production sector during an event is very costly. In
addition, there is significant agricultural activity in the southeast US which is vulnerable
to hurricane damage.
A framework for reducing vulnerability to weather and climate hazards is
illustrated in Fig. 8. Institutional capacity, political priorities, patterns of perception, land
use policies and technological capacity all influence the impacts of weather and climate
extremes, and the consequent environmental, economic, social, cultural, and demographic
impacts. All of these factors rely on information provided by scientific inquiry.
(2) The Rio Grande Basin
This area comprises parts of Colorado, New Mexico, Texas and Mexico (Fig. 9), possibly
“the world’s longest border defined by a river.” The Rio Grande is dry by the time it
reaches El Paso, being recharged further to the south.
A. Southern Great Plains
In Texas a significant redistribution of agricultural areas between1940 and 1987
(Fig. 10), coupled with the present small fraction of the state’s economy (ca. 3%)
represented by agriculture reduce the potential effects of precipitation variability for this
sector (Fig. 11). However some of the high-tech industry (e.g., manufacturing of
computer chips) presently driving the Texas economy is highly dependent on supplies of
both water and energy, and increases in temperature have the potential to render
reservoirs too warm to efficiently provide cooling water for electric power generation.
B. Texas-Mexico border
This is an area of high vulnerability to climate impacts, primarily because of the
scarcity of water, but also due to the linked problems of poverty, poor public health (high
incidence of hepatitis), unemployment and lack of education (Fig. 12). It was noted that
“vulnerability” is a variable standard – if communities have no air conditioning, e.g., its
loss is not felt.
C. Lower Rio Grande
Water supply and quality are problematic. Urban demand is growing rapidly, with
concomitant pressures to reduce irrigation demand. There are frequent droughts,
motivated in part by teleconnections to ENSO (drier in La Niña years). Public health
problems are exacerbated by the corollary problem of water quality: many residents
obtain drinking water from irrigation ditches. Precipitation variability also plays a role, as
flash floods are a problem (Fig. 13).
D. Climate impacts in the political sphere
A brief digression into the impacts of Hurricane Mitch (1998) revealed not only the
considerable damage done to Central American agriculture (Figs. 14-16), but also the
“ripple” effect of such damage on demographic patterns: the number of illegal
immigrants detained at the U.S.-Mexico border doubled that year (Fig. 17). Impactrelated issues, and their interrelations are summarized in Fig. 18.
(3) Remote sensing and agriculture
Rather than impacts of climate on society, this section dealt with the impacts of
advances in remote sensing (both surface- and satellite-based) on the practice of
agriculture. Mention was made of the Oklahoma Mesonet (http://okmesonet.ocs.ou.edu),
a dense network of automated weather stations (Fig. 19). Data gathered by this network
provides the potential for detailed mesoscale forecasting, with concomitant benefits not
only to agriculture, but also weather prediction in general, including flood mitigation.
Other applications of mesonet-gathered information: renewable power generation,
emergency management (e.g., chemical road spills) and transportation. It can be seen
from Fig. 19 that Oklahoma’s mesonet array is considerably denser than the extant
network of National Weather Service stations in Texas. Interestingly, agriculture
accounts for about 3% of gross state product in both states
(http://www.odoc.state.ok.us/index.html).
Satellite remote sensing can provide a synoptic overview of land usage (Fig. 20),
and facilitate processes such as mapping of field boundaries, crop and irrigation
monitoring and the application of precision farming techniques (Fig. 21). It is anticipated
that such techniques, including fine-tuning of seed and fertilizer types (as well as
application schedules for the latter), integrated pest management techniques, and yield
monitoring (among numerous others, see Fig. 22) will be adopted incrementally,
presumably as the benefits of precision techniques become more widely appreciated.
References
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Kerr, Richard A., Forecasters Learning to Read a Hurricane’s Mind. SCIENCE 284: 563565 APRIL 23, 1999.
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