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Strunk and White, Strunk and White, The Elements of StyleThe Elements of Style..

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Global Global WarmingWarming

NEWS: later

NEWS: Wilkens Ice Shelf is disintegrating

Last Class…Last Class…

NEWS: later

What is the definition of a greenhouse gas?

What are examples of greenhouse gases?

What is the most effective greenhouse gas?

Absorbers in our Absorbers in our AtmosphereAtmosphere

Earth emits much of its radiation here.CO2 and H2O are the most important greenhouse gases.

Last Class…Last Class…

NEWS: later

Power* In

235 W/m2

Power* out

235 W/m2

Power* In

229 W/m2

Power* out

229 W/m2

Power*: P = T4

= 5.67x10-8 W/m2 K4

T = 253 K or -3o F

T = 252 K or -3o F

For Earth:

For Venus:

We argued that the energy/sec of sunlight into the atmosphere equals the energy/sec out of the atmosphere.

Last Class…Last Class…

NEWS: later

Power* In

235 W/m2

Power* out

235 W/m2

Power* In

229 W/m2

Power* out

229 W/m2

Power*: P = T4

= 5.67x10-8 W/m2 K4

T = 253 K or -3o F

T = 252 K or -3o F

For Earth:

For Venus:

We argued that the energy/sec of sunlight (and IR radiation) into the atmosphere equals the energy/sec out of the atmosphere.

Power Power balanbalan

cece

VisibleSunlight

Infrared Radiation

Our assumption: The power of sunlight entering the atmosphere equals the power of IR light exiting the atmosphere

VisibleSunlight

Infrared Radiation

Correction: The power of sunlight and IR light entering the atmosphere equals the power of IR light exiting the atmosphere

VENUS vs EARTHVENUS vs EARTH

VenusVenus EarthEarthSurface PressureSurface Pressure 92 bar92 bar 1 bar1 bar

Surface Surface TemperatureTemperature

735 K (872 735 K (872 F)*F)* 288 K (59 F)288 K (59 F)

Bulk Density Bulk Density (g/cm(g/cm33))

5.2455.245 5.5125.512

Radius (km) Radius (km) 60526052 63786378

NN22 3.5%3.5% 78%78%

COCO22 96.5%96.5% 0.038%0.038%

* Hot enough to melt lead

VENUS vs EARTHVENUS vs EARTH

VenusVenus EarthEarthSurface PressureSurface Pressure 92 bar92 bar 1 bar1 bar

Surface Surface TemperatureTemperature

735 K (872 735 K (872 F)*F)* 288 K (59 F)288 K (59 F)

Bulk Density Bulk Density (g/cm(g/cm33))

5.2455.245 5.5125.512

Radius (km) Radius (km) 60526052 63786378

NN22 3.5%3.5% 78%78%

COCO22 96.5%96.5% 0.038%0.038%

HH22OO 0%0% 3%*3%*

* But there is 1000 times this amount on the surface!

Runaway Greenhouse: Recipe*Runaway Greenhouse: Recipe*

Heat Earth with COHeat Earth with CO22 , H , H220 evaporates.0 evaporates. Water further heats Earth.Water further heats Earth. More water then evaporates.More water then evaporates. This causes more heating. This causes more heating. More water evaporates.More water evaporates. And so on.And so on.

* Easier than instant pudding

Topic: Global WarmingTopic: Global WarmingScience & SocietyScience & Society

Today’s Lecture includes:

Why no life on Venus?Are we affecting Earth?Saucy political intrigue.

NEWS: later

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The Increase in COThe Increase in CO22

Measuring Earth’s Measuring Earth’s temperaturetemperature

1) Thousands of thermometers on weather stations & ships

2) Satellite microwave emission from O2 (lower 5 km)

3) Measure change of temperature with height. Greenhouse warming causes the lower 5-10 km to heat and above to cool.

4) Make measurements throughout the day, everyday. 5) Isotopic composition in ice cores (Past climate)6) Coral growth (Past climate)7) Tree ring widths. (Past climate)8) Human records, e.g. the freezing of the Thames

(London).

Date by counting layers, Volcanic eruptions…Colder temperatures: lighter H & O isotopes(for which H2O has a higher vapor pressure). USGS core lab

Har

vard

Res

ear c

h

Evidence that Earth is warmingEvidence that Earth is warming

Reconstruction of the Northern Hemisphere temperatures coral and ice-core proxy records (Mann et al. 1999, 1998, Jones & Briff 1992)

Figure 3.1Figure 3.1

IPCC

Intergovernmental Intergovernmental Panel on Climate Panel on Climate

ChangeChange

February 9, 2007, Paris

Figure 3.10Figure 3.10

IPCC

Rising Ocean Rising Ocean temperaturestemperatures

The Atlantic, Pacific and Indian oceans have warmed by 0.06 C in since 1955 (Science, 24 March 2000, pg 2225). This result was determined by compiling millions of measurements of the deep oceans made from 1948 to 1995.

More recently (Science, 13 April 2001), climate calculations indicate that the anthropogenic rise in CO2 explains this sea warming.

Coral reefs are dying all around the world, likely as a result of the warming of the oceans.

From Jim Hansen

• 2002 all-time record melt area • Melting up to elevation of 2000 m• 16% increase from 1979 to 2002 70 meters thinning in 5 years

Satellite-era record melt of 2002 was exceeded in 2005. Source: Waleed Abdalati, Goddard Space Flight Center

Increasing Melt Area on Increasing Melt Area on GreenlandGreenland

Melt descending into a moulin, a vertical shaftcarrying water to ice sheet base.

Source: Roger Braithwaite, University of Manchester (UK)

GREENLAND MELTGREENLAND MELT

Jakobshavn Ice Stream in Greenland

Discharge from major Greenland ice streams is accelerating markedly.

Source: Prof. Konrad Steffen, Univ. of Colorado

Greenland’s largest outlet glacier, drains 6.5% of the ice sheet.Doubling of flow speed from 1997 to 2003. Complete melting would raise sea level by 7 meters.

MeltinMelting Polar g Polar

IceIce

The northeast passage is predicted to open up in 2050, allowing ships to sail from London to Japan along the coast of Siberia.

Increasingly higher number of Polar Bears drowning. (Science 2007)

Sea levels Sea levels are risingare rising

Present predictions based on glacial melt rates indicate that the sea level will rise 10-20 inches in the next century. Rate of rise is 0.1 inch since 1993 (NASA).

Melt all of the ice sheets: 70 m increase in sea level (above scale in meters)

BeijingBangladesh

New York

Washington

Global Warming?Global Warming?

Earth has warmed 1Earth has warmed 1° ° F in the last centuryF in the last century

The COThe CO22 abundance has risen by 20% since 1950. abundance has risen by 20% since 1950.

The oceans have warmed 0.06 C since 1955.The oceans have warmed 0.06 C since 1955.

The sea level is rising 0.1 inches each year.The sea level is rising 0.1 inches each year.

Global Warming & SocietyGlobal Warming & Society

Good word: Orwellian: 1) of or relating to the Good word: Orwellian: 1) of or relating to the works by George Orwell, particularly the novel works by George Orwell, particularly the novel 1984, about a future totalitarian state. 2) A policy 1984, about a future totalitarian state. 2) A policy controlled by propoganda, misinformation and denial controlled by propoganda, misinformation and denial of truth, and manipulation of history. of truth, and manipulation of history.

Political IntriguePolitical Intrigue

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USA consumes 25% of the World’s Oil

USA has 4.5% of the World Population

CountryCountry Pop (M)Pop (M) BTU/capitaBTU/capita GNP/capitaGNP/capita

USAUSA 267267 327327 26,02626,026

FranceFrance 5858 147147 26,43726,437

GermanyGermany 8282 157157 29,60729,607

JapanJapan 125125 142142 40,84640,846

MexicoMexico 9191 5757 2,7432,743

BrazilBrazil 159159 2525 4,3274,327

IndiaIndia 929929 1111 349349

ChinaChina 1,2201,220 2727 572572

EgyptEgypt 6262 2121 763763

TurkeyTurkey 6161 3333 2,7072,707

World Energy Consumption 1995

Kyoto Kyoto ProtocolProtocol

Emission of COEmission of CO22

USA69% Oil for Transportation92% Coal for Electricity 40% of all petroleum is expended by transportation

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Associate Editor / Air Force Mag.

CanadaVenezuelaMexico

Saudi ArabiaIraqKuwait

Kyoto ProtocolKyoto Protocol20022002

In 1997 the Kyoto Protocol was formulated.In 1997 the Kyoto Protocol was formulated. The treaty calls for the 38 largest industrial nations to reduce The treaty calls for the 38 largest industrial nations to reduce

emissions due to greenhouse gases.emissions due to greenhouse gases. But the Protocol would not take effect until it is ratified by the But the Protocol would not take effect until it is ratified by the

nations emitting at least 55% of the greenhouse gases. nations emitting at least 55% of the greenhouse gases. In March of 2001, the USA rejected the Protocol on the grounds In March of 2001, the USA rejected the Protocol on the grounds

that it would hurt the economy. that it would hurt the economy. The USA, with 4% of the world population, produces 25% of The USA, with 4% of the world population, produces 25% of

the greenhouse gases. The protocol would require the USA to the greenhouse gases. The protocol would require the USA to reduce the emissions by 7% by 2010. reduce the emissions by 7% by 2010.

In June 2002, the European Union and many other countries, In June 2002, the European Union and many other countries, including Japan, proceeded to ratify the Protocol, without the including Japan, proceeded to ratify the Protocol, without the USA. The union of countries produce almost 55% of the USA. The union of countries produce almost 55% of the greenhouse gases.greenhouse gases.

Kyoto Protocol 2005Kyoto Protocol 2005

Green: signed & ratifiedGreen: signed & ratified Yellow: ratification pendingYellow: ratification pending Red: signed, refused ratificationRed: signed, refused ratification Grey: not involvedGrey: not involved

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Article in Le Monde Article in Le Monde (2004)(2004)

20052005

60 Minutes 60 Minutes interview with Dr. interview with Dr. James HansenJames Hansen

Paris vs Paris vs TucsonTucson

1960 metro stops in Paris!

LONDONLONDON

Summary: Global WarmingSummary: Global Warming

The COThe CO2 2 abundance has risen by 20% since 1950.abundance has risen by 20% since 1950.

Earth’s atmosphere has warmed 1Earth’s atmosphere has warmed 1° ° F in the last century. F in the last century.

Oceans have warmed 0.06 C since 1955Oceans have warmed 0.06 C since 1955

The sea level is rising 0.1 inches each yearThe sea level is rising 0.1 inches each year

If Greenland melts, the sea level will rise 7.2 mIf Greenland melts, the sea level will rise 7.2 m

If Antarctic ice sheet melts the sea will rise 61 mIf Antarctic ice sheet melts the sea will rise 61 m

Sources of InformationSources of Information

1. Primary Sources:

1. Science http://www.sciencemag.org/

2. Nature http://www.nature.com/nature/index.html

2. Secondary Sources:

1. Scientific American http://www.sciam.com/

3. USA Scientists: National Academy of Sciences

1. http://www.nasonline.org/site/PageServer

4. International Panel: IPCC* (http://www.ipcc.ch/)

* Intergovernmental Panel on Climate Change (Nobel Peace Prize along with Al Gore)