JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Security Administration under Contract DE-AC04-94AL85000.

Jeff Tsao

Physical, Chemical and Nano Sciences Center

Sandia National Laboratories

Some Simple Physics of Global Warming

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Controversy, complexity, and uncertainty

http://www.ipcc.ch/

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Topics

• The Earth's Delicate Heat Balance

• Earth’s Temperature History

• The Earth's Sluggish Carbon Balance

• Humanity's Appetite for Energy and Carbon

• What Can We Do?

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Earth’s Delicate Heat Balance

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Simple calculation of the earth’s temperature

Mkmrsun 4.12

FCKT

K

r

r

r

rTT

r

rrTrT

earth

sunearth

earth

earth

sunsunearth

sunearth

earthsunsunearthearth

436279

000,000,100,2

1600,11)5780(

44

4

4)4()4(

4

2

2

2

244

2

22424

Mkmrearth 013.02

Power radiating from the earth

Power radiating from the sun

Fraction of power that intercepts the earth

Stefan’s Law

Actual

Mkmr sunearth 150

FCKTearth 5714287

Predicted (Stockholm)

(Albuquerque)

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

H2O: Ice, Clouds, Water Vapor

http://visibleearth.nasa.gov/

Adapted from http://en.wikipedia.org/wiki/Greenhouse_effect

Reflection from the surface (including ice and snow)

Reflection from clouds

Absorption by clouds

Emission by clouds

Absorption by water vapor

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Greenhouse gases

Oxygen

Nitrogen 78

20.9

1

0.04

% of earth’satmosphere

Adapted from http://en.wikipedia.org/wiki/Greenhouse_effect

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Earth’s Temperature History

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

The 450,000-year temperature history

18

16

14

12

10

8

6

4

2Ap

pro

xim

ate

av

era

ge

ea

rth

te

mp

era

ture

(°C

)

Adapted from http://www.seed.slb.com/en/scictr/watch/climate_change/change.htm

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

The 1,000-year temperature and CO2 history

National Oceanic and Atmospheric Administration (http://lwf.ncdc.noaa.gov/paleo/about-collage.html)

The evaporation rate of the rare, heavy 18O isotope of H2O is slower than that of the common, light 16O isotope of H2O, and depends on temperature

http://www.nasa.gov/lb/worldbook/wbkids/k_evaporation.html

Adapted from http://www.koshland-science-museum.org/exhibitgcc/images/historical03.gif

(°F)(ppm)

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Earth’s Sluggish Carbon Balance

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Earth’s carbon sources and sinks

IPCC4 Figure 7.3

Cdeep-ocean

τ ~ 100 years

cbiosphjanthro

Pre-1900’s: Cbiosph = cdeep-ocean

1900’s-2000’s: Cbiosph > cdeep-ocean

Post-2000’s?: Cbiosph > cdeep-ocean

Post-2100’s?: Cbiosph = cdeep-ocean

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

The earth’s response to C emission scenarios

http://cisac.stanford.edu/news/bps_chief_scientist_discusses_secure_sustainable_energy_in_drell_lecture_20080205/

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

Humanity’s Appetitefor Energy and Carbon

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

The “IPAT” Relationship

Ė (

1012

W)

13.5 TW43 TW

Ė = (GDP/N) · N · (Ė/GDP)

per capita Gross Domestic Product

Popu-lation

Impact = Affluence · Population · Technology

Energy Intensity

Energy Consump-

tion Rate

11 Bper

6.1 Bper

5,000 US$

25,000 US$

0.45 W/($/yr)

0.15 W/($/yr)

Adapted from M.I. Hoffert, K. Caldeira, A.K. Jain, E.F. Haites, L.D.D. Harvey, S.D. Potter, M.E. Schlesinger, S.H. Schneider, R.G. Watts, T.M.L. Wigley, and D.J. Wuebbles, "Energy implications of future stabilization of atmospheric CO2 content," Nature 395, 881-884 (Oct 1998)

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

The sluggish decrease in carbon intensity

0.3 GtC/(TW-yr)

0.49 GtC/(TW-yr)

Adapted from M.I. Hoffert, K. Caldeira, A.K. Jain, E.F. Haites, L.D.D. Harvey, S.D. Potter, M.E. Schlesinger, S.H. Schneider, R.G. Watts, T.M.L. Wigley, and D.J. Wuebbles, "Energy implications of future stabilization of atmospheric CO2 content," Nature 395, 881-884 (Oct 1998)

http://www.undp.org/energy/activities/wea/index.html

JY Tsao ∙ Some Simple Physics of Global Warming ∙ 2008 April

• Plan A: Sequester the Carbon

• Plan B: Switch to Non-Fossil Fuels– E.g., there is plenty of solar (an area the size of Venezuela could power the world)– But not economical yet, so need R&D and carbon tax– But a carbon tax could be a drag on GDP, unless it substitutes for income tax

• Plan C: Climate Engineering– Global gardening, atmospheric water/ice nucleation, earth albedo manipulation, …

• Plan D: Adapt to global warming– Developed nations are the cause, but undeveloped countries are least able to afford to

adapt– What is the cost of adapting, and who should pay?

What can we do?