Transcript aapg-san-antonio-peterson

Modern Observations:
Temperature Data and their
Interpretation
Thomas C. Peterson
NOAA’s National Climatic Data Center
Asheville, North Carolina
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American Association of Petroleum Geologists
San Antonio, TX
April 23, 2007
Outline
• How the climate is changing according to the
data
• Efforts to insure the data base is robust
• Post production quality assurance
• Climate change attribution
• Final comment
– Each of the above topics could be a full
presentation on their own
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American Association of Petroleum Geologists
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April 23, 2007
How the climate is changing
according to the data
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April 23, 2007
Global temperatures are rising
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San Antonio, TX
April 23, 2007
US temperatures are generally similar
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April 23, 2007
Global warming is not uniform around
the globe, e.g., the SE US cooled
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From TX
IPCC,
2007
April 23, 2007
More warming in the last few decades
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TX
From IPCC,
2007
April 23, 2007
The recent observed climate change is
beyond the bounds of natural variability
From IPCC 2007
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April 23, 2007
The hottest summertime temperatures are
increasing
North American average
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From Peterson et al., 2008
American Association of Petroleum Geologists
San Antonio, TX
April 23, 2007
Coldest winter temperatures are
warming faster
North American average
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From Peterson et al., 2008
American Association of Petroleum Geologists
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April 23, 2007
Efforts to insure the data base is
robust
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April 23, 2007
International data exchange
Note drop in data
during WWII
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Source: Scott Woodruff
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April 23, 2007
Quality control
• A wide variety of checks have been
developed to identify erroneous data points.
Bilma Niger
From Peterson et al., 1998.
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April 23, 2007
Homogeneity adjustments – Sea
Surface Temperature example
From UK Met
Office Hadley
Centre
From Smith and Reynolds, 2002
• Adjust
historical
data to
make them
equivalent
to being
observed
by modern
instruments
at current
station
locations
SST measured before ~ 1941 are significantly cooler
than later SST, owing to change from using uninsulated
buckets to a mixture of insulated buckets and engine American Association of Petroleum Geologists
14 intakes.
coolant water
San Antonio, TX
April 23, 2007
Homogeneity adjustments – Land
air temperature station example
Reno Nevada annual minimum temperature
From Menne et al., 2008
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• Red is fully
adjusted
• Black is only
time of
observation
adjusted
• Top:
temperatures
• Bottom:
difference
between Reno
and mean of 10
nearest
neighbors
American Association of Petroleum Geologists
San Antonio, TX
April 23, 2007
Spatial interpolation to fill in data
sparse areas
• Prevents bias
towards areas
with good
international
data exchange
• NCDC’s
approach uses
Empirical
Orthogonal
Teleconnection
Functions
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April 23, 2007
Post production quality assurance
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April 23, 2007
Comparison with other data sets:
They show the same thing
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From
18 Menne and Peterson, 2007, updated from IPCC 2007
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April 23, 2007
Comparison of land and oceans:
They show the same thing
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April 23, 2007
Comparison of urban and rural stations:
They show the same thing
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From Peterson and Owen (2005) and IPCC
2007TX
April 23, 2007
Some stations have poor siting
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American
Association offrom
Petroleum
Geologists
Photographs
Davey
Sanand
Antonio,
TX
Pielke,
April 23, 2007
Sr. (2005)
Comparison of stations with poor and
good siting: They show the same thing
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From Peterson
2006
Antonio,
TX warming April 23, 2007
Poorly cited stations in this example San
show
less
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Doesn’t a station over concrete have a warm
bias compared to a station over grass?
• For climate change purposes the relevant
questions are:
– Does the bias change over time?
– Can the changing bias be accounted for?
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Photographs from Davey
and Pielke, Sr. (2005)
American Association of Petroleum Geologists
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A poorly sited station compared to
its neighbors
Raw data
Homogeneity adjusted data
Marysville, CA, USHCN v2
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• The station
is 2º C
warmer than
neighbors
• But adjusted
data’s trend
agrees with
its neighbors
American Association of Petroleum Geologists
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April 23, 2007
Comparison of homogeneous and homogeniety
adjusted stations: They show the same thing
The stations with good siting only
needed two minor and offsetting
time of observation adjustments
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From Peterson
2006
San Antonio, TX
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April 23, 2007
Comparison of surface and upper air: Satellites
and balloon data also show warming.
From IPCC,
2007
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April 23, 2007
Comparison with non-thermometer data
• Data from sources other than surface
thermometers indicate that the world is
warming
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April 23, 2007
Arctic sea-ice is shrinking
http://nsdl.org/resource/2200/20061002125757277T
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April 23, 2007
Antarctic sea ice is increasing
• The data indicate
cooling in the far
southern oceans
• So increases in
Antarctic sea ice
supports the data
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April 23, 2007
Lakes and rivers are freezing later
and thawing earlier
From IPCC,
2007
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American Association
of Petroleum
Figure
4.5 Geologists
San Antonio, TX
April 23, 2007
Glaciers are melting
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From IPCC, 2007
San Antonio, TX
April 23, 2007
Sea level is rising
From IPCC, 2007
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April 23, 2007
Plants and animals are acting as if
it is warming
• Plants are blooming 1-3 days/decade
earlier
– “Altered timing of spring events has been
reported for a broad multitude of species
and locations” (IPCC 2007).
• Animals species are moving poleward
– “Many studies of species abundances and
distributions corroborate predicted
systematic shifts related to changes in
climatic regimes” (IPCC 2007)
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April 23, 2007
Climate change attribution
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April 23, 2007
Detection and attribution
• The climate has warmed
– Statistically significant change
– Climate change has been detected
• But what has caused the detected
change?
– Climate change attribution
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April 23, 2007
• Each
climate
forcing
has its own
fingerprint
of change
in the
climate.
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From CCSP 1.1
San Antonio, TX
April 23, 2007
Models with and without human produced
climate forcings reveal:
• “Most of the observed increase in global
average temperatures since the mid-20th
century is very likely due to the observed
increase in anthropogenic greenhouse gas
concentrations” (IPCC 2007).
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April 23, 2007
Final comment
• Stepping out into record hot weather, a
friend who is an expert on climate change
detection and attribution was asked if the
high temperatures they were experiencing
were due to global warming
• He responded:
– You can’t attribute any one day’s temperature
to global warming
– But unusually warm weather like that does give
us the privilege of experiencing the weather we
are bequeathing our children and grandchildren
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The End
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April 23, 2007
But didn’t all the scientists predict
global cooling back in the 1970s?
Global cooling articles only 10% total climate change articles
7 cooling articles
20 neutral articles
44 warming articles
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From Peterson et al., 2008.
April 23, 2007
Aren’t all the solutions painful?
• Efficiency can
work wonders
From:
Brown et al., 2005
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– Electricity use
per refrigerator
has decreased to
<30% of 1972
value
– Meanwhile,
refrigerator size
has increased
– And refrigerator
price has
decreased (in
constant dollars).
American Association of Petroleum Geologists
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April 23, 2007
Selected References
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Brown, M.A., F. Southworth, T. K. Stovall, 2005: Towards a Climate-Friendly Built
Environment. Pew Center on Global Climate Change, 91 pp.
Menne, M.J. and T.C. Peterson, 2007: Surface Temperature, in State of the Climate in
2006. Arguez, A. ed., Bull. Amer. Meteor. Soc., 88, S11–S12.
Menne, M.J., C.N. Williams, Jr., and R.S. Vose, 2008: The United States Historical
Climatology Network serial monthly temperature data - Version 2. BAMS, submitted.
Peterson, Thomas C., Russell S. Vose, Richard Schmoyer, and Vyachevslav Razuvaëv, 1998:
GHCN quality control of monthly temperature data. International Journal of Climatology,
18, 1169-1179.
Peterson, Thomas C. and Timothy W. Owen, 2005: Urban Heat Island Assessment:
Metadata are Important. Journal of Climate, 18, 2637-2646.
Peterson, Thomas C., 2006: Examination of Potential Biases in Air Temperature Caused by
Poor Station Locations. Bulletin of the American Meteorological Society, 87, 1073-1080.
Peterson, Thomas C., Xuebin Zhang, Manola Brunet India, Jorge Luis Vázquez Aguirre,
2008: Changes in North American extremes derived from daily weather data. Journal of
Geophysical Research, in press.
Peterson, Thomas C., Marjorie McGuirk, Tamara G. Houston, Andrew H. Horvitz and
Michael F. Wehner, 2008: Climate Variability and Change with Implications for
Transportation, National Research Council, in press.
Peterson, Thomas C.,William M. Connolley and John Fleck, 2008: The myth of the 1970s
global cooling scientific consensus. Bulletin of the American Meteorological Society, in
press.
Smith, T.M. and R.W. Reynolds, 2002: Bias corrections for historical sea surface
temperatures based on marine air temperatures. J. Climate, 15 73-87.
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