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Global WarmingGlobal Warmingto the Mass Audienceto the Mass Audience

ExplainingExplaining

Glenn SchwartzGlenn SchwartzChief Meteorologist NBC10

PhiladelphiaChief Meteorologist NBC10

Philadelphia

Global WarmingGlobal WarmingVisual EvidenceVisual Evidence

Shepard Glacier-1913Glacier National Park, Montana

Shepard Glacier-1913Glacier National Park, Montana

Shepard Glacier-2005Glacier National Park, Montana

Shepard Glacier-2005Glacier National Park, Montana

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Comparison ph

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Arctic Ice Cover ChangesArctic Ice Cover Changes Arctic Ice Cover ChangesArctic Ice Cover Changes

Arctic Ice Cover ChangesArctic Ice Cover Changes Feb. Arctic Sea Ice AgeFeb. Arctic Sea Ice Age1981-2000 2009

But the scariestpicture of all

But the scariestpicture of all

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Debate Used to be About Science

Now It’s About Politics

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The Debate RagesThe Debate RagesBastardi: winter snowstorms prove global warming hoax

Washington Times: February Snow Storms “Undermine the Case for Global Warming One

“More Mega-Snowstorms Coming -- Global Warming to Blame?Get used to heavy U.S. snowstorms, scientists say.”

-OR-Flake at a Time”

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Are we scaring our children?

Are we scaring our children?

From a child who is yet to lose all her baby teeth: "I worry about [global warming] because I don't want to die."

One out of three children aged 6 to 11 fears that Ma Earth won't exist when they grow up,

75 percent of black children and 65 percent of Hispanic children believe that the planet will be irrevocably damaged by the time they reach adulthood.

Global WarmingGlobal WarmingBack to the ScienceBack to the Science

Greenhouse EffectGreenhouse Effect• Atmosphere is

transparent to incoming solar radiation

• Outgoing Longwave infrared radiation is trapped by greenhouse gasses

• Atmosphere is transparent to incoming solar radiation

• Outgoing Longwave infrared radiation is trapped by greenhouse gassesgasses

• The most dominant greenhouse gas is water vapor

• Changes in the composition of the atmosphere interfere with these energy flows

gasses• The most dominant

greenhouse gas is water vapor

• Changes in the composition of the atmosphere interfere with these energy flows

Mauna Loa Monthly Mean Carbon Dioxide1955 - 2005

Mauna Loa Monthly Mean Carbon Dioxide1955 - 2005

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Global WarmingGlobal WarmingEvidence in Ice CoresEvidence in Ice Cores

World Carbon Emission1750 - Present

World Carbon Emission1750 - Present

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North America Carbon Emission1780 - Present

North America Carbon Emission1780 - Present Past 1000 Years (“Hockey Stick Graph”)Past 1000 Years (“Hockey Stick Graph”)

Controversial

Another Study – Past 2000 YearsAnother Study – Past 2000 Years

Controversial

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Globalwarmingart.comGlobalwarmingart.comGreat GraphicsGreat Graphics

p gjpg

Global WarmingGlobal WarmingEvidence from Weather

InstrumentsEvidence from Weather

Instruments

Earth’s Temperature ChangesEarth’s Temperature Changes

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It’s Warming Again!It’s Warming Again! Global Temperature ChangesPast 10 Years

Global Temperature ChangesPast 10 Years

Winter Temp ChangeWinter Temp Change Summer Temp ChangeSummer Temp Change

Global WarmingGlobal WarmingComputer ModelsComputer Models

“Hindcasting” Past 100 Years“Hindcasting” Past 100 Years

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Forecasting Next 100 YearsForecasting Next 100 YearsGlobal WarmingGlobal WarmingIs Abrupt Climate Change

Possible?Is Abrupt Climate Change

Possible?

Greenland Ice Sheet FlowsGreenland Ice Sheet Flows• Accelerating Since 1996• Accelerates Glacier

Sliding• May be much faster

than Computer Models

• Accelerating Since 1996• Accelerates Glacier

Sliding• May be much faster

than Computer Models than Computer Models Indicate

• Can Further Melting Result in Large Sea Level Rises in 100s of years instead of 1000s of years?

than Computer Models Indicate

• Can Further Melting Result in Large Sea Level Rises in 100s of years instead of 1000s of years?

Temperature Change ForecastTemperature Change Forecast• Lower End is

significant• High End is

catastrophic

• Lower End is significant

• High End is catastrophicp

• Middle Area is most likely

• Even that is MAJOR

p

• Middle Area is most likely

• Even that is MAJOR

Sea Level Rise ForecastSea Level Rise Forecast• Lower End causes

storms to flood more

• Higher End floods coastal cities

• Lower End causes storms to flood more

• Higher End floods coastal citiescoastal cities

• Middle End is most likely statistically

• More rapid rise is possible

coastal cities

• Middle End is most likely statistically

• More rapid rise is possible

Global WarmingGlobal WarmingA Response to Skeptics

QuestionsA Response to Skeptics

Questions

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It’s All Because of the Sun

It’s All Because of the SunSunSun

The Warming Ended in 1998

The Warming Ended in 199819981998

Actual Temperature TrendActual Temperature Trend

The Warming Ended in 1998The Warming Ended in 1998• That was a Strong El Nino year that

added to the warming• 2005 about as warm, but had no El Nino

to Skew the data

• That was a Strong El Nino year that added to the warming

• 2005 about as warm, but had no El Nino to Skew the data In the 70s they said an

i iIn the 70s they said an

i iice age was comingice age was coming

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In the 70s they said an ice age was comingIn the 70s they said an ice age was coming• This was more in the popular media than

the scientific articles• A book by a non-scientist called “The

Cooling” became a best-seller• But it was NOT the prevailing scientific

i t th ti (I th )

• This was more in the popular media than the scientific articles

• A book by a non-scientist called “The Cooling” became a best-seller

• But it was NOT the prevailing scientific i t th ti (I th )view at the time (I was there)

• Even the National Geographic and Newsweek suggested the possibility of warming due to CO2 in the future

view at the time (I was there)• Even the National Geographic and

Newsweek suggested the possibility of warming due to CO2 in the future

It was just as warm in the Medieval warm

It was just as warm in the Medieval warm the Medieval warm

period as todaythe Medieval warm

period as today

Medieval Warm PeriodMedieval Warm PeriodIt was just as warm in the Medieval warm

period as today It was just as warm in the Medieval warm

period as today • Maybe it was warmer in Europe, but

there’s no evidence that it was that warm worldwide

• This is GLOBAL warming, not regional

• Maybe it was warmer in Europe, but there’s no evidence that it was that warm worldwide

• This is GLOBAL warming, not regional

Ice core records show that CO2 increase comes AFTER the

Ice core records show that CO2 increase comes AFTER the comes AFTER the warming. So does

warming increase CO2?

comes AFTER the warming. So does

warming increase CO2?

Vostok Ice Core RecordsVostok Ice Core Records

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Does warming increase CO2?Does warming increase CO2?

• Warming did start about 800 years before CO2 increase

• Some other forcing (Milankovich) started the warming

• Warming oceans release CO2

• Warming did start about 800 years before CO2 increase

• Some other forcing (Milankovich) started the warming

• Warming oceans release CO2• CO2 then causes temp to rise, which

causes more CO2 (feedback!)• CO2 could be stored in deep ocean during

ice ages, and then released when warmed• We can not explain temperature

variations WITHOUT CO2

• CO2 then causes temp to rise, which causes more CO2 (feedback!)

• CO2 could be stored in deep ocean during ice ages, and then released when warmed

• We can not explain temperature variations WITHOUT CO2

Why are the Antarctic i h t i ?

Why are the Antarctic i h t i ?ice sheets growing?ice sheets growing?

Why are the Antarctic ice sheets growing?Why are the Antarctic ice sheets growing?

• It doesn’t have to warm everywhere• Ice sheet thickens due to more snow due

to warming

• It doesn’t have to warm everywhere• Ice sheet thickens due to more snow due

to warming We Can’t even predict the weather next week. H di t 100

We Can’t even predict the weather next week. H di t 100 How can we predict 100

years?How can we predict 100

years?

How can we predict 100 years?How can we predict 100 years?

• Climate vs. weather• Averaging over time removes random

nature• We can predict tomorrow with near 90%

accuracy, and computer models of the t h th i h

• Climate vs. weather• Averaging over time removes random

nature• We can predict tomorrow with near 90%

accuracy, and computer models of the t h th i hatmosphere are the main reason why

• Testing models by going back and predicting up to today is pretty good (the trends are right)

atmosphere are the main reason why• Testing models by going back and

predicting up to today is pretty good (the trends are right)

The computer models already proven to be The computer models already proven to be already proven to be

too warmalready proven to be

too warm

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Hansen Forecasts and ActualHansen Forecasts and Actual Computer models too warmComputer models too warm

• 3 scenarios from IPCC. Middle one is doing well

• Models correctly predicted cooling of stratosphere

• Models correctly predicted big warming f ti

• 3 scenarios from IPCC. Middle one is doing well

• Models correctly predicted cooling of stratosphere

• Models correctly predicted big warming f tiof arctic

• Models correctly predicted oceans to warm

• Models correctly predicted cooling rate due to volcanic eruptions

of arctic• Models correctly predicted oceans to

warm• Models correctly predicted cooling rate

due to volcanic eruptions

Climate models don’t take clouds into

Climate models don’t take clouds into take clouds into

accounttake clouds into

account

Models don’t take clouds into accountModels don’t take clouds into account

• ALL models DO take clouds into account• The type of clouds is very important and

there is uncertainty

• ALL models DO take clouds into account• The type of clouds is very important and

there is uncertainty

Some places are cooling; others have

record cold days.

Some places are cooling; others have

record cold days. record cold days. Doesn’t that disprove

it?

record cold days. Doesn’t that disprove

it?

Cooling and record cold disprove?Cooling and record cold disprove?

• The whole earth doesn’t warm uniformly-some places will cool

• But there are MANY more record highs than record lows around the world

• The whole earth doesn’t warm uniformly-some places will cool

• But there are MANY more record highs than record lows around the world