Jay Grymes WAFB Chief Meteorologist LSU AgCenter Climatologist LSU AgOutlook January 2010 Changing Climate... Linkages to LA Agriculture

“Global Warming” generally refers to the apparent warming of generally refers to the apparent warming of the Earth over the past 100+ years... and the Earth over the past 100+ years... and implies a human impact or influence implies a human impact or influence “Climate Change” refers to periodic shifts -- and temporal and refers to periodic shifts -- and temporal and spatial variability -- of Earth’s local, regional, spatial variability -- of Earth’s local, regional, and global climate and global climate may include a human factor, but acknowledges may include a human factor, but acknowledges that these variations have always occurred that these variations have always occurred “climate change” is more than the changes in “climate change” is more than the changes in temperature temperature

NOAA 3-Month Climate Outlooks Don’t over-interpret these “outlooks”! Source: NOAA / NWS Climate Prediction Center Think of these as ‘Confidence Maps’ and not indicators of the amount of departure

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 long- term climatic patterns” Comparison of Monthly Average Rainfall: NW LA vs. SE LA

‘Wet’ October -- generally ‘wet’ statewide generally ‘wet’ statewide Source: NWS Doppler radar composite

‘Dry’ November -- ‘dry’ to ‘very-dry’ statewide ‘dry’ to ‘very-dry’ statewide

Source: NWS Doppler radar composite ‘Mixed’ December -- ‘dry’ North to ‘record-wet’ south ‘dry’ North to ‘record-wet’ south

Source: NWS Doppler radar composite ‘Dry’ January (so far) -- generally ‘dry’ statewide generally ‘dry’ statewide

El Niño is Back Source: NOAA Climate Prediction Center

El Niño ‘Signature’ along the Gulf Coast: ‘Active’ Sub-Tropical Jet El Niño ‘Signature’ along the Gulf Coast: ‘Active’ Sub-Tropical Jet Sub-Tropical Jet ”Warm” SSTs More Frequent Gulf Lows

Forecast Model Predictions for the current El Niño: as of mid-December Source: Current El Niño... expected to persist at ‘moderate to strong’ intensity into Spring 2010 La Niña La Nada El Niño

ENSO – El Niño / Southern Oscillation Three Phases: Three Phases: El Niño (“warm” ocean phase) La Niña (“cool” ocean phase) La Nada (“neutral” ocean temps) El Niño La Niña La Nada

U.S. Rainfall Trends since mid-1960s (Dark Green = 2”+ per decade) Source: NOAA National Climatic Data Center

Regional / local scale variability in moisture characteristics Source: Nat’l Climate Data Center

The ‘Acknowledged’ Global Temperature Record

Source: Surface Temperature Reconstructions for the Last 2,000 Years (2006). National Research Council, National Academy of Sciences. National Academies Press, Washington, DC. “Little Ice Age” Age” “Medieval Warm Period”

Fischer et al, 2002 A Warmer, CO 2 ‘Enriched’ Atmosphere... What’s missing?

IPCC (2007). Climate Change 2007: The Physical Science Basis – Summary for Policymakers CO 2 concentrations are believed to be the highest in least 650,000 years. the highest in least 650,000 years. CH 4 (methane) and N 2 O are bi-products of human activity, mainly as a result of human activity, mainly as a result of agriculture. agriculture. CO 2 CH 4 N2ON2ON2ON2O

Annual Precipitation Projections to 2100 : Two ‘Modeled’ Examples

CCC 2100 Hadley2 Model 2100 Southeast Mixed Forest Tropical Broadleaf Forest Savanna/Woodland Grassland Temperate Deciduous Forest Shrub Woodland Current and Future Southern Ecosystems (MAPSS Biogeography Model) Current Canadian 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

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.” One guy’s perspective?!?

Jay Grymes WAFB Chief Meteorologist LSU AgCenter Climatologist wafb.com lsu.edu 225 / “Thank You!”