Climate is Always ChangingRegional, national and global trends

Lecturer: Pam Knox, University of GeorgiaAgricultural Climatologist

Outline

1. Introduction: Climate vs. Weather

2. Evidence of changing climate: Natural and human-induced

3. Climate trends in the last 100 years: Temperature, precipitation

4. What do we expect in the next 100 years?

Climate vs. Weather

What is the difference between climate and weather?

Climate is like a seasonal batting average but weather is like an individual “at bat.”

Climate tells us about the average or expected conditions in an area and the range of possible conditions, while weather tells us the short-term occurrences .

Types of Climate

FloridaWest Virginia

Colorado Washington

Evidence of Climate Variability

Lake Lanier, GA 2007 drought

Mississippi River 1993 flood

Evidence of Changing Climate

Palouse Hills east of Walla Walla, WA

Evidence of Changing Climate

Bald Peak, NY

Death Valley, CACross Plains, WI

Mr. Rainier, WA

Evidence of Climate Change

Petrified Forest, AZMesa Verde, CO

Human-Induced Changes in Climate

Contrails

Wildfires

Pollution

Human-Induced Changes in Climate

Urban heat island Land use changes

Regional Temperature Trends

Regional Temperature Trends

Regional Temperature Trends

National Temperature Trends

National Temperature Trend

National Temperature Trends in Extremes

Global Temperature Trend

Global Temperature Trends

National Precipitation Trends

National Precipitation Trends

Seasonal Precipitation Trends

http://www.globalchange.gov/

Global Precipitation Trends

Predicted Trends in Temperature

Across the United States, temperatures are predicted to increase over the next 100 years, but the amount of warming predicted depends on the particular model used.

Predicted Trends in Precipitation

Precipitation across the US is harder for the models to predict, and some models show increased precipitation while others show drying or no trend. Some datasets indicate that rainfall has become more intense with longer dry spells in between.

What changes in climate can we expect and when?

• Average temperatures will likely increase in all seasons by 5-10 °F over the next 100 years

• Day vs. nighttime temperatures will both increase but not necessarily at the same rate

• Extremes in maximum temperature will cause added heat stress

• Growing seasons will lengthen

What changes in climate can we expect and when?

• Rainfall changes are hard to predict due to model differences between different global climate models

• Individual rain storms are likely to increase in intensity

• Longer dry spells may occur between rain storms

• Less snowfall and more liquid precipitation

• Evaporation will increase due to the higher temperatures

• Lower average streamflows and higher floods

Summary

In this module we have covered:

• Climate vs. weather• Evidence of changing climate• Regional, national and global climate

trends• Predictions for future climate

Livestock and PoultryEnvironmental Learning Center

Project Support

This project was supported by Agricultural and Food Research Initiative Competitive Grant No. 2011-67003-30206 from the USDA National Institute of Food and Agriculture.

www.animalagclimatechange.org

National Lead: University of Nebraska

Regional Partners: University of Georgia; Cornell University; University of Minnesota; Texas A&M AgriLife Extension, and Washington State University.

Project Partners

Our Mission Animal agriculture in a changing climate fosters animal productionpractices that are: environmentally sound and economically viable,and that create resiliency for animal producers and their partners.

Photo credits

http://en.wikipedia.org/wiki/Creative_CommonsAll photos are from public domain sources or through Wikipedia’s Creative Commons.

http://commons.wikimedia.org/wiki/File:Matt_LaPorta_swinging.jpg

http://commons.wikimedia.org/wiki/File:Autumn-farm-buggy-tool-shed-pubJPG_-_West_Virginia_-_ForestWander.jpg

http://commons.wikimedia.org/wiki/File:Flickr_-_Nicholas_T_-_Windswept.jpg

http://commons.wikimedia.org/wiki/File:Islamorada_Florida.jpg

http://commons.wikimedia.org/wiki/File:Rainforest_living_up_to_its_name.jpg

http://commons.wikimedia.org/wiki/File:Glacial_Erratic_on_Bald_Peak_2010.JPG

http://commons.wikimedia.org/wiki/File:Palouse_hills_northeast_of_Walla_Walla.jpg

http://commons.wikimedia.org/wiki/File:Drumlin_-_Cross_Plains_-_WI_-_USA.JPG

http://commons.wikimedia.org/wiki/File:Shoreline_Butte_Death_Valley.jpg

http://commons.wikimedia.org/wiki/File:River_Forks_Park.jpg

http://commons.wikimedia.org/wiki/File:FEMA_-_3438_-_Photograph_by_Andrea_Booher_taken_on_07-09-1993_in_Missouri.jpg

http://commons.wikimedia.org/wiki/File:Glacial_striation_21149.JPG

http://commons.wikimedia.org/wiki/File:Chaco_Canyon_Chetro_Ketl_great_kiva_plaza_NPS.jpg#file

http://commons.wikimedia.org/wiki/File:Petrified_forest_log_1_md.jpg

http://commons.wikimedia.org/wiki/File:Contrails.jpg

http://commons.wikimedia.org/wiki/File:Wildfiretopanga.jpg

http://commons.wikimedia.org/wiki/File:Mesa_Verde.jpg

http://commons.wikimedia.org/wiki/File:Air_.pollution_1.jpg

http://commons.wikimedia.org/wiki/File:Cotton_field_kv44.jpg

http://commons.wikimedia.org/wiki/File:Crops.jpg

http://earthobservatory.nasa.gov/Features/GreenRoof/

http://www.warwickhughes.com/climate/atlanta2.htm

http://commons.wikimedia.org/wiki/File:NOAAprecipitationtrend.jpg

Livestock and PoultryEnvironmental Learning Center

Project Support

This project was supported by Agricultural and Food Research Initiative Competitive Grant No. 2011-67003-30206 from the USDA National Institute of Food and Agriculture.

www.animalagclimatechange.org

National Lead: University of Nebraska

Regional Partners: University of Georgia; Cornell University; University of Minnesota; Texas A&M AgriLife Extension, and Washington State University.

Project Partners

Our Mission Animal agriculture in a changing climate fosters animal productionpractices that are: environmentally sound and economically viable,and that create resiliency for animal producers and their partners.