Dave Siegel

Director, Institute for Computational Earth System Science

Professor, Department of Geography

March 22, 2007

Global Warming & You

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

Nature, 444, 752-755, 2006

coolocean

warmocean

warm ocean = low NPP

Atmospheric CO2

Dave Keeling

•Pre-industrial = 280 ppm & present = 385 ppm

•Trends are related to fossil fuel releases

•Annual cycle due to terrestrial biosphere exchanges

Mauna Loa

Carbon Dioxide Sources

Figure 10.29

Carbon Dioxide Sources

IPCC [2001]

Predicting Future Climates

Need emission scenarios – socioeconomic prediction!!

IPCC [2001]

IPCC [2001]

IPCC [2007]

Likely Future Climates

Warming to the Inconvenient FactsBy 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/~davey

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 convectionENSO drives much of interannual weather

variations

El Nino & weather

southeast US and western S.

America are both wetter in winter

much of Alaska and Pacific NW are warmer in

winterAustralia,

Indonesia, and S. Africa are drier

NH winter

NH summer

Nature, 444, 752-755, 2006

for period 1999-2004

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

Wintertempanomalies

El Niño in the United States

Winterprecipanomalies

El Niño in Australia

El Niño & Diseases

low pressure high pressure

intense convection

upwelling of cold, nutrient-rich water

(good fisheries)

Normal State

convective loop

El Niño State

convective loop reversesincreased

convection, rainfall

thermocline is depressed in the eastern Pacific and raised in the

western Pacific

fisheries along the coast failrain 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