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Global WarmingWinter Storming
Ellen E. MartinDept of Geological Sciences
Snow angelOcala , Florida, Jan. 8,
2010
• If global warming is really happening…
• Why was this winter so cold and wet?
• Winter 2010 -second coldest winter on record in Florida
• Need to understand:• the difference between climate
and weather• what :global warming” means
Snowstorm in Washington DC, Feb. 2010
Climate vs. Weather• Weather
– The state of the atmosphere at a given time and place with respect to temperature, cloudiness, moisture, wind, pressure
• Climate– 30 year average of atmospheric state
(World Meteorological Organization)
– “expected weather”
Global Warming
• A tendency for the global mean surface temperature to increase
Average:• Land and ocean• All latitudes• All seasons
Global Mean Temperature
Mean Temperature-
Gainesville
58°F
72°F
Measured temperature record for past ~150 yrs
MedievalWarmth
Little Ice Age
Northern Hemisphere Temperatures for the past 1000 yrs
Time series, Alaska
Kilimanjaro, Africa
19791979
20002000
NASA Goddard Space Flight Center
Arctic Sea Ice- summer
http://www.youtube.com/watch?v=JMQ21p93JZc
• Whether the world is getting warmer isn’t controversial
Political debate focused on whether the world is getting warmer due to:
- natural causesor- man-made greenhouse gases (the greenhouse effect)
Centuries
Millennia
Millions of years
Zachos et al., 2001
ColderMore ice
So, why was this winter so
cold?•El Niño
Conditions in US during El Niño
winters
Vancouver
Vancouver
• Global warming = climate= global
• Cold winter in southeast US = weather= local
El Nino
La Nina
Strong evidence that the global mean surface temperature of earth is increasing
Related to El Niño conditions
Record of atmospheric CO2 from ice cores
Record of atmospheric CO2
from direct measurements
(Hawaii)
Greenhouse Gases
IPCC 2007
Ice core data
Ice Core CO2 RecordModern rate of increased compared to past
400 ky
Atmosphere
Earth’s Greenhouse
(S/4)(1-)
Earth
T4
Ts = 58°F
IncomingShort wave
energy
OutgoingLong wave
energy
Global Carbon Cycle
NASA- earthobservatory (~1990)
+3/yr
+0.5/yr
+1.5/yr
Reforestation
Deforestation
40,000,000
826
7
CO2 by Country
Per capita2002
Fate of Anthropogenic CO2
Kump, Kasting and Crane
Consume all fossil fuels (2300) 2100 ppmV CO2
(CCD)
Temperature- Greenhouse Gas Correlation
NOAA/NCDC
Correlation between temperature and CO2 concentration
Anthropogenic Greenhouse Gases
IPCC 2007
Gases
Processes
Climate System
Atmosphere
Geosphere- land
Cryosphere-ice
Hydrosphere-ocean
Biosphere- vegetation
