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Changing Climate . . .
Linkages to LA Agriculture
Jay Grymes
WAFB Chief Meteorologist
LSU AgCenter Climatologist
LSU AgOutlook 2010
21 January 2010
“Global Warming”
generally refers to the apparent warming of
the Earth over the past 100+ years . . . and
implies a human impact or influence
“Climate Change”
refers to periodic shifts -- and temporal and
spatial variability -- of Earth’s local, regional,
and global climate
may include a human factor, but acknowledges
that these variations have always occurred
“climate change” is more than the changes in
temperature
NOAA 3-Month
Climate Outlooks
Don’t over-interpret
these “outlooks”!
Think of these as
‘Confidence Maps’
and not indicators of
the amount of
departure
Source: NOAA / NWS Climate Prediction Center
www.cpc.ncep.noaa.gov
What about Louisiana’s Climate?
-- has demonstrated change over the last
100+ years
-- changes and variability are not identical
across the state
-- changes are not necessarily 1-directional
“To understand the impacts and importance of
variability and change, we recognize the state’s longterm climatic patterns”
Comparison of Monthly Average Rainfall:
NW LA vs. SE LA
‘Wet’ October -generally ‘wet’ statewide
Source: NWS Doppler radar composite
http://weather.water.gov
‘Dry’ November -‘dry’ to ‘very-dry’ statewide
Source: NWS Doppler radar composite
http://weather.water.gov
‘Mixed’ December -‘dry’ North to ‘record-wet’ south
Source: NWS Doppler radar composite
http://weather.water.gov
‘Dry’ January (so far) -generally ‘dry’ statewide
Source: NWS Doppler radar composite
http://weather.water.gov
El Niño
is Back
Source: NOAA Climate Prediction Center
www.cpc.ncep.noaa.gov
El Niño ‘Signature’ along the Gulf Coast:
‘Active’ Sub-Tropical Jet
Sub-Tropical Jet
More Frequent
Gulf Lows
”Warm” SSTs
Forecast Model Predictions for the current El Niño:
as of mid-December
El Niño
Current El Niño . . .
expected to persist at
‘moderate to strong’ intensity
into Spring 2010
La Nada
La Niña
Source:
http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html#figure
ENSO – El Niño / Southern Oscillation
Three Phases:
El Niño (“warm” ocean phase)
La Niña (“cool” ocean phase)
La Nada (“neutral” ocean temps)
El Niño
La Nada
La Niña
U.S. Rainfall Trends since mid-1960s
(Dark Green = 2”+ per decade)
Source: NOAA National Climatic Data Center
www.ncdc.noaa.edu
Regional / local scale
variability in moisture
characteristics
Source:
Nat’l Climate Data Center
www.ncdc.noaa.gov
The ‘Acknowledged’ Global Temperature Record
The ‘Acknowledged’ Global Temperature Record
“Medieval Warm
Period”
“Little Ice
Age”
Source:
Surface Temperature Reconstructions for the Last 2,000 Years (2006).
National Research Council, National Academy of Sciences.
National Academies Press, Washington, DC.
A Warmer, CO2 ‘Enriched’ Atmosphere . . .
What’s missing?
Fischer et al, 2002
CO2
CO2 concentrations are believed to be
the highest in least 650,000 years.
CH4
CH4 (methane) and N2O are bi-products of
human activity, mainly as a result of
agriculture.
N2O
IPCC (2007). Climate Change 2007:
The Physical Science Basis –
Summary for Policymakers
Annual Precipitation Projections to 2100 :
Two ‘Modeled’ Examples
Current and Future Southern Ecosystems
(MAPSS Biogeography Model)
Temperate Deciduous Forest
Southeast Mixed Forest
Tropical Broadleaf Forest
Savanna/Woodland
Current
Grassland
Shrub Woodland
Canadian Model 2100
CCC 2100
Hadley2 Model 2100
Does this imply a
semi-permanent
“El Nino-like” climate
for the future?
Louisiana’s Climate Outlook . . .
for the Next 10 to 100 years
Probable:
- modest warming
- greater year-to-year variability -more extreme events?
Possible:
- significant warming
- substantial drop in rainfall in LA
American Assoc. of State Climatologists (2001)
“. . . climate predictions have not demonstrated skill
in projecting future variability and changes in . . .
growing seasons, drought, flood-producing rainfall,
heat waves, tropical cyclones and winter storms.”
“ [However] . . . effective mitigation/adaptation
policies and strategies need not depend on the
precision and confidence in future predictions …”
. . . and . . .
“… a lack of predictive skill in GCMs should not be
used as a justification to avoid policy development
and implementation that fosters ‘environmental
stewardship’ and ecological responsibility.”
AASC (2001)
Source: Dr. Virginia Burkett, USGS
One guy’s perspective?!?
At a 2006 EPA workshop, I proposed:
“Even if the threat of global warming/climate change
is being overstated, the most ‘modest’ of impacts
could have dire effects on Louisiana . . .
Louisiana may be the most adversely impacted
of any state in the nation.”
“Thank You!”
Jay Grymes
WAFB Chief Meteorologist
LSU AgCenter Climatologist
jgrymes @ wafb.com
jgrymes @ lsu.edu
225 / 215-4713