Climate ChangeClimate Change

Have you noticed any change in our summer weather?

Our winter weather?

The arrival of spring?

Have you noticed any change in our summer weather?

Our winter weather?

The arrival of spring?

Do you believe that we will experience significant global warming during this century?

Do you believe that we will experience significant global warming during this century?

QuestionsQuestions

Are global warming and climate change the same thing?

What is the difference between climate and weather?

What is the greenhouse effect? What is the most abundant greenhouse gas? Is climate change real? What evidence is there for climate change? Does the hole in the ozone layer cause climate

change?

Are global warming and climate change the same thing?

What is the difference between climate and weather?

What is the greenhouse effect? What is the most abundant greenhouse gas? Is climate change real? What evidence is there for climate change? Does the hole in the ozone layer cause climate

change?

What’s the Difference?What’s the Difference?

Global Climate Change– Any significant change in measures of climate (temperature,

precipitation or wind) lasting for an extended period (decades or longer).

Global Warming– Average increase in the temperature of the atmosphere, which can

contribute to changes in global climate patterns.

Global Climate Change– Any significant change in measures of climate (temperature,

precipitation or wind) lasting for an extended period (decades or longer).

Global Warming– Average increase in the temperature of the atmosphere, which can

contribute to changes in global climate patterns.

Weather vs. ClimateWeather vs. Climate

Weather – Short-term (minutes to

months) changes in the atmosphere

Climate – Long-term average

pattern of weather in a particular area

– Typically use 30 years of data

Weather – Short-term (minutes to

months) changes in the atmosphere

Climate – Long-term average

pattern of weather in a particular area

– Typically use 30 years of data

What are the major Greenhouse Gases? What are the major Greenhouse Gases?

Greenhouse GasesGreenhouse Gases

Water Vapor: 0-4% Carbon Dioxide (CO2):

0.036% Methane (CH4):

0.00017% Nitrous Oxide (N2O):

0.00003% CFC’s

Water Vapor: 0-4% Carbon Dioxide (CO2):

0.036% Methane (CH4):

0.00017% Nitrous Oxide (N2O):

0.00003% CFC’s

Greenhouse EffectGreenhouse Effect

Earth’s average temperature would be 0 ºF without the greenhouse effect compared to the average temperature of 60 ºF that we experience

Global Energy BudgetGlobal Energy Budget

CLIMATE CHANGE AND HUMAN ACTIVITIES

CLIMATE CHANGE AND HUMAN ACTIVITIES

– Warmer temperatures in Alaska, Russia, and the Arctic are melting permafrost releasing more CO2 and CH4 into the troposphere.

– During the last century, the world’s sea level rose by 10-20 cm, mostly due to runoff from melting and land-based ice and the expansion of ocean water as temperatures rise.

– Warmer temperatures in Alaska, Russia, and the Arctic are melting permafrost releasing more CO2 and CH4 into the troposphere.

– During the last century, the world’s sea level rose by 10-20 cm, mostly due to runoff from melting and land-based ice and the expansion of ocean water as temperatures rise.

Burning of fossil fuels

Methane from cattle—really!

Burning of fossil fuels

Methane from cattle—really!

Why Should We Be Concerned about a Warmer Earth?

Why Should We Be Concerned about a Warmer Earth?

A rapid increase in the temperature of the troposphere during this century would give us little time to deal with its harmful effects.

As a prevention strategy scientists urge to cut global CO2 emissions in half over the next 50 years.– This could prevent changes in the earth’s climate

system that would last for tens of thousands of years.

A rapid increase in the temperature of the troposphere during this century would give us little time to deal with its harmful effects.

As a prevention strategy scientists urge to cut global CO2 emissions in half over the next 50 years.– This could prevent changes in the earth’s climate

system that would last for tens of thousands of years.

Effects of Higher CO2 Levels on Photosynthesis

Effects of Higher CO2 Levels on Photosynthesis

Increased CO2 in the troposphere can increase plant photosynthesis (PS) but:– The increase in PS would slow as the plants

reach maturity.– Carbon stored by the plants would be returned to

the atmosphere as CO2 when the plants die.– Increased PS decreases the amount of carbon

stored in the soil.– Tree growth may temporarily slow CO2 emissions

in the S. Hemisphere but is likely to increase CO2 emissions in the N. Hemisphere.

Increased CO2 in the troposphere can increase plant photosynthesis (PS) but:– The increase in PS would slow as the plants

reach maturity.– Carbon stored by the plants would be returned to

the atmosphere as CO2 when the plants die.– Increased PS decreases the amount of carbon

stored in the soil.– Tree growth may temporarily slow CO2 emissions

in the S. Hemisphere but is likely to increase CO2 emissions in the N. Hemisphere.

FACTORS AFFECTING THE EARTH’S TEMPERATURE

FACTORS AFFECTING THE EARTH’S TEMPERATURE

Aerosol and soot pollutants produced by human activities can warm or cool the atmosphere, but such effects will decrease with any decline in outdoor air pollution.

Warmer air can release methane gas stored in bogs, wetlands, and tundra soils and accelerate global warming.

Aerosol and soot pollutants produced by human activities can warm or cool the atmosphere, but such effects will decrease with any decline in outdoor air pollution.

Warmer air can release methane gas stored in bogs, wetlands, and tundra soils and accelerate global warming.

EFFECTS OF GLOBAL CLIMATE CHANGE

EFFECTS OF GLOBAL CLIMATE CHANGE

A warmer climate would have beneficial and harmful effects but poor nations in the tropics would suffer the most.

Some of the world’s floating ice and land-based glaciers are slowly melting and are helping warm the troposphere by reflecting less sunlight back into space.

A warmer climate would have beneficial and harmful effects but poor nations in the tropics would suffer the most.

Some of the world’s floating ice and land-based glaciers are slowly melting and are helping warm the troposphere by reflecting less sunlight back into space.

GLOBAL CLIMATE CHANGEGLOBAL CLIMATE CHANGE

Evidence that the earth’s troposphere is warming, mostly because of human actions:– The last decade was the hottest in recorded

history.– Since 1900, the earth’s average tropospheric

temperature has risen 0.6 C°.– Over the past 50 years, Arctic temperatures have

risen almost twice as fast as those in the rest of the world.

Evidence that the earth’s troposphere is warming, mostly because of human actions:– The last decade was the hottest in recorded

history.– Since 1900, the earth’s average tropospheric

temperature has risen 0.6 C°.– Over the past 50 years, Arctic temperatures have

risen almost twice as fast as those in the rest of the world.

Key IndicatorsKey Indicators

Sea Level Carbon Dioxide Concentration Global Surface Temperature Artic Sea Ice Land Ice

Sea Level Carbon Dioxide Concentration Global Surface Temperature Artic Sea Ice Land Ice

EvidenceEvidence

Carbon Dioxide Levels in Relation to Global Temperature

Carbon Dioxide Levels in Relation to Global Temperature

EvidenceEvidence

Sea Level Rise– Global sea level rose 17 cm (6.7 in.) in the last century – Rate in the last decade nearly double that of the last

century

Global Temperature Rise– Earth has warmed since 1880 with most of warming

occurring since the 1970s– 20 warmest years occurred since 1981– 10 warmest years occurred in the past 12 years.

Sea Level Rise– Global sea level rose 17 cm (6.7 in.) in the last century – Rate in the last decade nearly double that of the last

century

Global Temperature Rise– Earth has warmed since 1880 with most of warming

occurring since the 1970s– 20 warmest years occurred since 1981– 10 warmest years occurred in the past 12 years.

EvidenceEvidence

Warming Oceans– Top 700 m (2,300 ft) of ocean showing warming of

0.302 °F since 1969

Shrinking Ice Sheets– Greenland: lost 150-250 km3 (36-60 cubic miles) of ice

per year between 2002 and 2006– Antarctica: lost 152 km3 (36 cubic miles) of ice between

2002 and 2005

Warming Oceans– Top 700 m (2,300 ft) of ocean showing warming of

0.302 °F since 1969

Shrinking Ice Sheets– Greenland: lost 150-250 km3 (36-60 cubic miles) of ice

per year between 2002 and 2006– Antarctica: lost 152 km3 (36 cubic miles) of ice between

2002 and 2005

EvidenceEvidence

Declining Arctic sea ice– Extent and thickness of Arctic sea ice has declined

rapidly over last several decades

Glacial retreat– Retreating almost everywhere around the world

including Alps, Himalayas, Andes, Rockies, Alaska and Africa

Declining Arctic sea ice– Extent and thickness of Arctic sea ice has declined

rapidly over last several decades

Glacial retreat– Retreating almost everywhere around the world

including Alps, Himalayas, Andes, Rockies, Alaska and Africa

EvidenceEvidence

Extreme Events– Number of record high temps increasing since 1950– Number of record low temperature decreasing since

1950– Increasing numbers of intense rainfall events

Ocean Acidification– CO2 content of oceans increasing since 1750

– Currently increasing 2 billion tons per year– Increased ocean acidity by about 30%

Extreme Events– Number of record high temps increasing since 1950– Number of record low temperature decreasing since

1950– Increasing numbers of intense rainfall events

Ocean Acidification– CO2 content of oceans increasing since 1750

– Currently increasing 2 billion tons per year– Increased ocean acidity by about 30%

NASA InteractivesNASA Interactives

http://climate.nasa.gov/interactives/ http://climate.nasa.gov/interactives/

IPCCIPCC

Intergovernmental Panel on Climate Change Group of scientist from around the world that

review and assess information on climate change

Climate models and projections

Intergovernmental Panel on Climate Change Group of scientist from around the world that

review and assess information on climate change

Climate models and projections

EFFECTS OF GLOBAL WARMING

EFFECTS OF GLOBAL WARMING

A warmer climate would have harmful and beneficial effects.

What do you think are some beneficial impacts?

A warmer climate would have harmful and beneficial effects.

What do you think are some beneficial impacts?

Projections for North AmericaProjections for North America

Decreasing snowpack in the western mountains

5-20% increase in yields of rain-fed agriculture in some regions

Increased frequency, intensity and duration of heat waves

Decreasing snowpack in the western mountains

5-20% increase in yields of rain-fed agriculture in some regions

Increased frequency, intensity and duration of heat waves

Projections for Latin AmericaProjections for Latin America

Gradual replacement of tropical forest by savannah in eastern Amazon

Risk of significant biodiversity loss through species extinction in many tropical areas

Significant changes in water availability for human consumption, agriculture and energy generation

Gradual replacement of tropical forest by savannah in eastern Amazon

Risk of significant biodiversity loss through species extinction in many tropical areas

Significant changes in water availability for human consumption, agriculture and energy generation

Projections for EuropeProjections for Europe

Increased risk of inland flash floods

More frequent coastal flooding and erosion

Glacial retreat in mountainous areas

Reduced snow cover and winter tourism

Extensive species losses Reductions of crop

productivity in S. Europe

Increased risk of inland flash floods

More frequent coastal flooding and erosion

Glacial retreat in mountainous areas

Reduced snow cover and winter tourism

Extensive species losses Reductions of crop

productivity in S. Europe

Projections for AfricaProjections for Africa

By 2020, 75-250 million people are projected to be exposed to increased water stress

Yields from rain-fed agriculture could be reduced by up to 50% in some regions by 2020

Agricultural production, including access to food, may be severely compromised

By 2020, 75-250 million people are projected to be exposed to increased water stress

Yields from rain-fed agriculture could be reduced by up to 50% in some regions by 2020

Agricultural production, including access to food, may be severely compromised

Projections for AsiaProjections for Asia

Freshwater availability projected to decrease by 2050

Coastal areas at risk for increased flooding Death rate from disease associated with floods

and droughts expected to rise

Freshwater availability projected to decrease by 2050

Coastal areas at risk for increased flooding Death rate from disease associated with floods

and droughts expected to rise

Changing Ocean CurrentsChanging Ocean Currents

Global warming could alter ocean currents and cause both excessive warming and severe cooling.

Global warming could alter ocean currents and cause both excessive warming and severe cooling.

Figure 20-12Figure 20-12

Removing and Storing CO2Removing and Storing CO2

Methods for removing CO2 from the atmosphere or from smokestacks and storing (sequestering) it.

Methods for removing CO2 from the atmosphere or from smokestacks and storing (sequestering) it.

Figure 20-15Figure 20-15

Adaptation vs Mitigation Adaptation vs Mitigation

Wisconsin’s Climate 1950-2006Wisconsin’s Climate 1950-2006

Average temperature increased 1.5 ºF Greatest amount of warming in winter and spring, especially

NW Wisconsin Nighttime lows warming faster than daytime highs,

especially in summer Decline in extremely cold winter nights, especially in NW

Wisconsin Date of last spring freeze occurring 6-20 days earlier Date of first fall freeze occurring 3-8 days later Growing season increased up to 4 weeks Annual average precipitation increased 15% although parts

of the N became drier

Average temperature increased 1.5 ºF Greatest amount of warming in winter and spring, especially

NW Wisconsin Nighttime lows warming faster than daytime highs,

especially in summer Decline in extremely cold winter nights, especially in NW

Wisconsin Date of last spring freeze occurring 6-20 days earlier Date of first fall freeze occurring 3-8 days later Growing season increased up to 4 weeks Annual average precipitation increased 15% although parts

of the N became drier

Wisconsin’s Future Climate Projections

Wisconsin’s Future Climate Projections

4-9ºF increase by mid-21st Century Warming most pronounced in winter Fewer extremely cold winter nights and

more hot summer days Probability of greater than 3 in. rainstorms

will increase during spring and fall

4-9ºF increase by mid-21st Century Warming most pronounced in winter Fewer extremely cold winter nights and

more hot summer days Probability of greater than 3 in. rainstorms

will increase during spring and fall

Projected Change in theFrequency of 2" Precipitation Events (days/decade) from

1980 to 2055

Projected Change in the Frequency of 90 ºF Days Per

Year from 1980 to 2055

Projected Change in Annual Temp from 1980 to 2055

Projected Change in AverageWinter Temp from 1980 to 2055

Ice Cover on Madison LakesIce Cover on Madison Lakes

http://climatewisconsin.org/story/ice-cover http://climatewisconsin.org/story/ice-cover

Temperature ChangeTemperature Change

http://climatewisconsin.org/story/temperature-change

http://climatewisconsin.org/story/temperature-change

Shipping on the Great LakesShipping on the Great Lakes

http://climatewisconsin.org/story/great-lakes-shipping

http://climatewisconsin.org/story/great-lakes-shipping