Download Global Climate Systems Chapter 10

Global Warming & You
Dave Siegel
Director, Institute for Computational Earth System Science
Professor, Department of Geography
March 22, 2007
Recent Focus on Earth System Science…
What is Earth System Science?
The science
of global change
Global Climate Change
• Evidence for Global Warming
• - Intergovernmental Panel on Climate
Change (www.ipcc.ch)
• Role of the Carbon Cycle
• - Fossil vs. renewable carbon sources
• Consequences & Predictions
• Our options …
PNAS 2006;103;14288-14293.
Living foraminifera: Globigerinoides ruber
0.25 mm
PNAS 2006;103;14288-14293.
Qori Kalis ice tongue,
Quelccaya Glacier, Peru:
1978 vs. 2000
Source: Lonnie Thompson,
Ohio State University:
http://researchnews.osu.edu/
archive/glacgone.htm
"These glaciers are very
much like the canaries
once used in coal
mines. They're an
indicator of massive
changes taking place . .
.in the tropics."
Portage Glacier, Alaska
IPCC [2007]
http://www.geo.arizona.edu/dgesl/research/other/climate_change_and_sea_level/sea_level_rise/sea_level_rise.htm
Nature, 444, 752-755, 2006
Nature, 444, 752-755, 2006
cool
ocean
warm ocean = low NPP
warm
ocean
Nature, 444, 752-755, 2006
Atmospheric CO2
Mauna Loa
Dave Keeling
• Pre-industrial = 280 ppm & present = 385 ppm
• Trends are related to fossil fuel releases
• Annual cycle due to terrestrial biosphere exchanges
Carbon Dioxide Sources
Figure 10.29
Carbon Dioxide Sources
IPCC [2001]
Predicting Future Climates
Need emission scenarios – socioeconomic prediction!!
IPCC [2001]
IPCC [2001]
Likely Future Climates
IPCC [2007]
Warming to the Inconvenient Facts
By Michael Grunwald
Washington Post, July 23, 2006
•
“If the scientists are right about an apocalyptic
future of floods, droughts, dead coral reefs,
rising sea levels and advancing deserts, global
warming is an existential threat that should
affect our approach to just about every issue.
To take it seriously, we would have to change
the way we think about transportation,
agriculture, development, water resources,
natural disasters, foreign relations and more.”
Options
• Using less energy & increasing efficiency helps
• Must have zero-emission energy alternatives
(no fossil CO2!)
• - solar, wind, nuclear, advanced biofuels
• Carbon capture and sequestration
• - or -
• Continue “Business As Usual” and rely on
adaptation and/or engineering solutions?
Thank you for your attention
IPCC: www.ipcc.ch
Me: www.icess.ucsb.edu/~dav
Stott et al., 2000, Science: Annual-mean global mean near-surface temperature anomalies
(relative to 1881-1920) for the NATURAL, ANTHRO, and ALL ensembles. Ensemble members
are shown as colored lines, and observations are shown as a black line. Atmospheric CO2 levels
are 621 ppm in 2100 (scenario B2). HadCM3 model.
The UNFCCC
• An international treaty—the United Nations
Framework Convention on Climate Change
• Over a decade ago, many countries joined this
treaty to deal with global warming
• The Kyoto Protocol is an addition to the UNFCCC
and the 1992 Rio Accord
Kyoto Protocol
• Reduce the intensity of global warming, 38
industrialized nations must lower emissions
of 6 greenhouse gases by 2008-2012
• Greenhouse gases to be reduced by an
average 5.2% below 1990 levels
• Implemented just last month
• May not be enough…
ENSO (El Niño Southern Oscillation)
El Niño is the abnormal warming of surface waters in
the eastern Pacific – named by Peruvians who
noticed that it often occurred around Christmas (”the
boy”) - also it came when fish catches were low…
southern oscillation - shift in the pressure and trade
wind patterns over the Pacific - implications for
location of the warm water pool and convection
ENSO drives much of interannual weather variations
El Nino & weather
NH winter
southeast US and
western S. America
are both wetter in
winter
much of Alaska and
Pacific NW are
warmer in winter
NH summer
Australia, Indonesia,
and S. Africa are
drier
for period 1999-2004
Nature, 444, 752-755, 2006
El Niño & Subtropical Jet Stream
• Hadley cells intensify as source of heat is now in
central equatorial Pacific
• Jet stream intensifies & takes south path
El Niño in the United States
Winter
temp
anomalies
El Niño in the United States
Winter
precip
anomalies
El Niño in Australia
El Niño & Diseases
intense convection
low pressure
Normal State
convective loop
high pressure
upwelling of cold,
nutrient-rich water
(good fisheries)
El Niño State
convective loop reverses
increased
convection,
rainfall
thermocline is depressed in the
eastern Pacific and raised in the
western Pacific
fisheries along
the coast fail
rain falls on
dry coastal
deserts
Present Conditions
97/98 El Niño
• The 97/98 El Niño was biggest of all time
Present Conditions
• NOAA Climate Prediction Center - March 3, 2005
•
A transition from weak warm-episode (El Niño)
conditions to ENSO-neutral conditions is expected
to continue during the next three months.
Regions
west
to
east