Global Warming - So What

8/14/2019 Global Warming - So What

1/64

Global Warming

So What?.

July 2009 .


2/64

Droughts Worsen .

Droughts Worsen.

Deserts Spread.

The Culprit? . ..

Damages from our emissions so farwill intensify fordecades to come.

The more stuff we put in the airnow,

the fasterthe damages worsen and

the worse they eventually get.

Evaporation


3/64

The Way It Is .

We are already experiencing

dangerous human interference in the climate system:

increased incidents of heat waves, of floods, of droughts,

of intense tropical storms, of accelerated sea level rise.

The issue now is whether we can avoid

catastrophic human influence on the climate system.

I believe we still have a good shot at

avoiding catastrophic interference.

I sometimes say that the situation we are in is like

driving a car with bad brakes toward a cliff in the fog.

President Obamas Science Adviser .

John Holdren, April 8, 2009 .


4/64

Oil Imports

Oil has become expensive; it stayed above $80 a barrel for months.

Gasoline last year topped $3 a gallon for months in the US.

The US imports 60% of its oil.

Thats up from 53% in 2000, when George W. Bush took over,

and 38% when his father took office.

The US imports twice as much oil as any other nation uses.

Texas uses 3.1 times as much oil as it pumps out,

Louisiana 4.1 times as much.

US oil production peaked in 1970. World oil use outpaces oil found by 3:1 each year, and rising.

World oil production is peaking over 2005-10.

The era of cheap gasoline in America is over.


5/64

Greenhouse Effect

Greenhouse gases in the

air (GHGs) intercept some

outgoing radiation andre-radiate it back down.

This warms Earth more.

More GHGs = warmer still.

Dark Earth absorbs sunlight.

Earth warms up and

radiates heat.

Light surfaces reflect sunlight. Those surfaces dont warm Earth much.

Changing a light surface (ice) to a dark one (water) warms Earth.

Changing a dark surface (forest) to a lighter one (desert) cools Earth.

Cyclic changes in solar output have warmed and cooled Earth modestly.By now,human GHGs warm Earth much more than solar changes do.


6/64

Greenhouse Gases

GHGs warm Earth by 32C (58F).

Earth would average 0F without them. Watervapor (H2O) does 2/3 of this warming.

But H2O stays up for only 2-3 weeks, on average.

Concentrations vary many-fold over time and space.

As Earth warms up, evaporation increases H2O in the air.This amplifies warming from other GHGs considerably. So,

scientists often treat H2O not as a GHG, but a feedback for other GHGs.

Carbon dioxide (CO2) does 55% of the remaining net warming.

Almost all US CO2 comes from burning coal, oil & natural gas.Per unit of energy, coal emits 4 units of CO2, oil 3, natural gas 2.

Methane (CH4, natural gas) does 16%.CH4 comes from wetlands, cows, rice, landfills, coal mines.

CFCs (old air conditioners, ozone hole) do 11%,

Nitrous oxide (N2O - fertilizers) does 5%, black soot most of the rest.

ozone (O3) 10%, net.


7/64

Vostok Ice Core Data

Vostok Ice Core DataFor hundreds of

thousands of years,

temperatures havetracked the levels of

GHGs CO2 and CH4

in the air.

The difference

between 190 and 280ppm of CO2 was

10C (18F) and

ice almost a mile deep

covering Chicago.

Thousand Years before PresentVimeux, Cuffey & Jouzel,Earth and Planetary Science

Letters 203: 829-843 (2002)

+ 2006 temperature

ppm = parts per million ppb = parts per billion


8/64CO2 Levels in the Air

So far, half the CO2 we emited has stayed in the air.

The rest has gone into carbon sinks

But oceancarbon sinks are fading.

The difference between 280 and 380 ppm of CO2 remains to be seen.Weve seen some of it so far.

300 ppm (maximum between ice ages)

AnnualAverages

Up38%

Accelerationbegan.

Disappearing forests weaken another sink.

But much of the effect is delayed. It materializes slowly.

- into oceans, trees, soils, rocks.


9/64

Sun vs Temp

- NASA

- World Radiation Center

Watts / m2 C

Solar Irradiance at Earth Orbit, Annual Average

In 2007, solar output was the lowest yet recorded (in 28 years), but

Earths air temperatures (land surface) were the highest yet recorded.

Global AirTemperature, Land Surface, 3-Year Moving Average


10/64

Clouds

Halfthe sunlight reaching our atmosphere makes it to the surface.

Barriers include blue sky (not black),

Clouds Clouds reflect some sunlight away, cooling Earth.

They also keep outbound heat in, warming Earth, esp. at night.

Low clouds cool Earth more than they warm it.

High clouds do the reverse.

Clouds cover a little more than half of Earth.

On balance, they cool Earth.

Changes in cloud cover affect global temperature.

So do changes in % high clouds vs low clouds.

Many factors affect cloud formation & distribution.

At night & going up over mountains, air cools.

Cool air holds less H2O, so it will often cloud up & rain.

clouds, haze & the ozone layer.


11/64

Sulfates& Cooling

Dark sulfates in the air block sunlight.

Sulfates make haze

More sulfates= cloudier = cooler.

Most sulfates come from burning coal,

SO2 goes up the smokestacks.

GHGs stay in the air many years,

GHG levels keep rising.

Sulfates currently offset 40% of warming from human GHGs.

It changes to SO4 (sulfate) up in the air.

That cools Earth.

Sulfate levels dont.

sulfates usually for days.

some from volcanoes.

&become cloud condensation nuclei.


12/64ulfate Cooling Un-Smooths GHG

warmingunmasked

majorcooling

cool

NASA GISS - Earths7,000 weather stations

- adjusted for urban

heat island effects

Sulfates up 52%.

Sulfate Levels in Greenland Icemilligrams of Sulfate per Ton of Ice

40

Krakatoaerupts

ElChichn

Mt.Pinatubo

Sulfate Cooling Un-Smooths GHG WarmingC

cool

sulfates still3x 1880 levels

WW I:more SO2

up the stacks

WW II:more SO2

1880 2000

GreatDepression

JFK-LBJExpansion:

more SO2

USSO2cuts start

Sulfates

fall 13%.

Soufriere,S Maria,

Pelee erupt

cool

61 891920

77 1161960

162 118CoolingoffsetsGHG

warming.

Sulfates up 46%.

cool

cool

Brown .cloud .growsover .India, .China. .

cool

cool

(Intergovernmental Panelon Climate Change, 2002)

cool

cool

warmingless SO2

up the stacks

Sulfatesup110%.

1900

Colimaerupts

cool

Agungeruptscooler

Katmaieruptscooler


13/64

Land warms more (faster) than oceans.

It warms more when & where its coldest:

in winter,

at night,

& especially

toward the poles.


14/64

Earth Is Heating Up. Earth now absorbs 0.5% more energy than it emits - .

a 435 million MW heat gain435 million MW

This absorption has been accelerating, from near zero in 1960.

Airat the land surface is 1.0C warmerthan 100 years ago.Half that warming happened in the last 25 years.

Another0.6Cwarming (so far) is in the pipeline.

Earth will warm another 0.6C,

Air at the sea surface is 0.8C warmerthan 100 years ago.

The oceans have gained ~10 x moreheat in 40 years

than ALL the energy humans have EVER used.

One MW can power several hundred US homes.~ means approximately, roughly, is about equal to

= 30x human energy use.

1C = 1.8F.

That is,

(75 million MW)

OurGreenhouse effect intensifies.

=100 x globalelectric supply

so it emits enough heat to balance absorption.


15/64

The Tipping Points Report to US & British Legislators - January 2006

in the US, to Senator Olympia Snowe (R-ME)

What would make climate change accelerate,

so natural forces defeat our efforts to slow it?

1 Disappearance of sea icemeans more heat is absorbed by the water below.

2

Carbon sinks fade & failin oceans & forests.

3 Methane release from permafrost

revs up warming in a vicious circle.


16/64

More Heat - So?Hurricanes convert ocean heat to powerful winds & heavy rains.

Intense hurricanes are becoming more common.

Higherhurricane energy closely tracks sea surface warming.

With more carbon, oceans have grown more acidic.

Warmerwater holds less dissolved oxygen.

Oceanswarmed 0.15C over 1997-2004, so

Warming was far strongest in the N Atlantic.

Water

North Atlantic Hurricane Activity

0.3

0.5

0.7

0.9

1.1

1.3

1.5

1945 1955 1965 1975 1985 1995 2005

Total Energy from Hurricanes / Year(Divided by Adjusted Baseline)

September Sea Surface Temperature(C - Baseline)

Emanuel, 2005

Percentage of Hurricanes, by Intensity

10%

20%

30%

40%

50%

1972 1977 1982 1987 1992 1997 2002

5-Year Averages

Category 1

Categories 2-3

Categories 4-5

weakest

strongest

Webster, 2005

All Ocean Basins Combined East of Caribbean, west of Africa6-18N, 20-60W

Shells dissolve easier.

Fish & mollusks suffer.

planktonabsorbed 7% less CO2.

CO2 uptake there fell by half.


17/64

Reservoirs in the SkyMountain glaciers and snowpacks

are dwindling ever faster.

Himalayan glaciers may vanish by 2035,

& with them

the Ganges River in the dry season,

the Indus River too, the Yellow River maybe.

Mountain snows melt earlier.

Californias San Joaquin River (Central Valley, US salad bowl)

could dry up by July.The Colorado and Rio Grande too?

The Colorados 10-year drought is the worst since white men came.

Lake Mead water levels dropped 60 feet from 2000 to 2003.

50% chance its functionally dry by 2021. .


18/64

Earths ThermostatGreenlandsice-melt rate rose150%over the past decade.

Its net melt-water already ~ US wateruse.

Arctic Oceaniceis shrinking fast.2007s minimum ice area was 20% below 2005s record.

Thats down 40% in 25 years.

In 2008, icepack volume was the lowest on record,

The icepack could melt away by fall in ~ 10 years

West Antarcticasnet ice-melt is ~ half of Greenlands.

Its smaller ice shelves, along the Antarctic Peninsula, are breaking up.

Sea level could rise more than 3 feet, in this century alone.

Thawing permafrost holds 2-4 xMOREcarbon than ALL the carbon

humans have EVER emitted.

Thawing permafrost will likely add 50-100ppm of CO2 to the air by 2100.

Frozen subsea methane hydrates hold even more carbon.

The Arctic Ocean has begun emitting big burps of methane.

Permafrost area shrank 7% from 1900 to 2000.

ice area the 2nd lowest.

and be gone all summer in ~ 50.


19/64

What Else?From 1979 to 2005, the tropics spread &

the sub-tropicarid belts grew ~140 miles toward the poles,

a century ahead of schedule.Forestfires now burn 6 x as much area / year as before 1986.

Severe drought hit 45% of North America in 2002,

so plants absorbed 50% less CO2.

Canadas forests recently turned into a net carbon source.

The Amazons 2005 drought was the worst in years,so the rainforest temporarily became a carbon source.

Australias 7-yeardrought is the worstin many centuries.North China & Argentinas Pampas now suffer 50-yeardroughts.

In 2007, a 100-yeardrought hammered Atlanta & the whole Southeast.

Californias 3-yeardrought is an official emergency.

In 2006-7, Los Angeles rainfall was the lowest on record.

Droughts


20/64

Is That All?No ..

Over the last 13 years, desertsgrew from 18 to 27% of Chinas area.

With more evaporation & irrigation,

many water tablesfall .

Remember the Ogalalla! .

Since 1985, halfthe lakes in Qinghai province (China) vanished.92% in Hebei (around Beijing).

Irrigation wells chase waterever deeper.

Water prices rise.

Inland seas and lakes dry up & vanish, for example:

the Aral Sea, Sea of Galilee, Lake Chad (Darfur), Lake Eyre.

More riversfail toreach the sea:

- the Yellow, Colorado, Indus, Darling Rivers so far.

Water

3-20 feet / year.

(aquifer under the Great Plains)


21/64

Turning Wheat into Cactus

In 2005-6, the Union of Concerned Scientists calculated how climate

would change for 9 Northeast and 6 Great Lakes states in 2 scenarios:

#1 - a transition away from fossil fuels, or

#2 - continued heavy reliance on them (business as usual emissions).

By 2085,

averaged across 15 states, the climate change would be like

moving 330 miles to the SSW (coal & oil use dwindle), or

moving 650 miles to the SSW (heavy coal & oil use).

Consider central Kansas, heart of wheat country.

330 miles to the SSW lies the area from Amarillo to Oklahoma City.650 miles to the SSW lies the area around Alpine & Ft. Stockton, Texas.

2 people / square mile. Cactus grows there.

Mesquite & sagebrush too.

No wheat


22/64

UN Chief on Climate Change

Some scientists are saying publicly that if humanity

goes on with business as usual, climate change could

lead to the collapse of civilization, even in the lifetime

of today's children.

United Nations Secretary General Ban Ki-Moon said I

think that is a correct assessment. He added carefully Ifwe take action today, it may not be too late.

September 24, 2007


23/64

By 2059, Once a Century Drought Can Cover 45% of Earth.

1969Supply-Demand Drought Index

1999.

Business

as UsualEmissions

2029 2059

DRY WET

0 1 5 16 36 36 16 5 1 0

% Occurrence in Control Run

in 20592 x CO2

Fig. 1 in David Rind, R. Goldberg, James Hansen, Cynthia

Rosenzweig, R. Ruedy, Potential Evapotranspiration andthe Likelihood of Future Droughts, Journal of GeophysicalResearch, Vol. 95, No. D7, 6/20/1990, 9983-10004.

Climate Model:NASA

GoddardInstitute for

Space Studies(GISS)

+4.2C+14% rain


24/64

Projected Droughts by Year .

Fig. 2 in Rind et al., 1990

0

10

20

30

40

50

60

70

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060

Occure

nce(%)

Dry

Drought

Extreme Drought

16%

5%

1%}Occurrence in Control Run

Over 2000-04, the average frequencies are 18% for Drought and 33% for Dry.

A weighted average for as dry as 11% of the time drought is ~ 27%.

Based on Supply-Demand Drought Index

2x

CO2

2xCO2

Once a century drought can cover 45% of Earths land by 2059.

Projected Drought ConditionsLand Surface, except Antarctica

June-August, Business as Usual Emissions


25/64

Thanks for the crystal ball.

BUT

Is any of this actually happening? .

Remember

forest fires, falling water tables,disappearing lakes and rivers,

spreading deserts?

(Please also remember11% of the time drought was projected to

increase to 27% of the time over 2000-2004.)

Now for the BIG PICTURE

YES.


26/64

Droughts Are Spreading Already.

Very Dry Areas - % of Global Land Area, 60S - 75N .

-5

0

5

10

15

20

25

30

1950 1960 1970 1980 1990 2000

%w

ithSevere

orExtremeDrou

ght-

.

PalmerDrough

tSeverityIndex

Global Warming - So What

Documents

Transcript of Global Warming - So What