Global Warming

CO2 needs to be added to the list!

• Not regulated as a pollutant under the U.S. Clean Air Act.– But most emissions

are CO2

• A greenhouse gas – Contributes to

global climate change

In the US…

Sources of C02

• US emissions1. 40 %

Petroleum products

2. 34 % coal

3. 20 % natural gas

Greenhouse Effect

• In a greenhouse, light enters but IR cannot escape

• CO2 in atmosphere allows light rays to enter but traps IR

• CO2 % in atmosphere has increased from 280 ppm in pre-Industrial time to present day value of 375.64 ppm (2003 data), 387 ppm (2009 data)

Rise in atmospheric CO2 in the last 50 years

Why the see-saw pattern? Why Mauna Loa?

Other Greenhouse Gases• Methane, water vapor, nitrous oxide

– Rice paddy, extraction of fossil fuel, raising of live stock (bovine flatulence) cause increase in methane

– Cutting of forests kills CO2 sink

• Some effects might be opposite of CO2: SO2

Increasing concentration of greenhouse gases

Gas Historic Level Current Level Warming potential comapred to CO2

Lifetime in Atmosphere (years)

CO2 280 ppm 387 ppm 1 5-200

CH4 700 ppb 1720 ppb 23 12

N2O 275 ppb 314 ppb 300 114

CFCs 0 ppt level 4000-8000 5-100

Perfluoro-methane (PFC)

40 pt 80 ppt 5700 50,000

Sulfur Hexafluoride (SF6)

0.01 ppt 3 ppt 22,000 3200

Greenhouse Effect: Is it Real?• How much CO2=How much rise of T?• More T = more evaporation = more cloud = Less

Temp…• Real rise or natural fluctuation?

– Data for the last 10ka indicate upto 6 °C fluctuation– Little ice age (1450 – 1850)– About 2/3rd of the centuries warming has taken place in

the last 25 years: 1990s were the warmest decade of the 20th century

– Based on 14,000 land and sea records from all over the world

– Ice core patterns –varied between 180 and 280 ppm in the last half million years

Evidence to Support Global Warming

• Intergovernmental Panel on Climate Change (IPCC)– An international panel of scientists and government officials

established in 1988 – Generated reports on the synthesis of scientific information

concerning climate change– 4th Assessment report 2007

• Documents observed trends in surface temperature, precipitation patterns, snow and ice cover, sea levels, storm intensity

• The IPCC concluded that it is more than 90% likely that most global warming is due to humans

– The Debate over climate change is over– 84% of people surveyed think humans contribute to global warming

• Predicts future changes

Effects of Global Warming

• Sea level rise• Extreme weather• Decreasing Biodiversity• Decline in Food Production• Effect on Health

Greatest air pollution problem: Global Warming

• www.nelson.wisc.edu/outreach/energy2006

Greenhouse Effect: Problems• Increasing ocean temperature:

– 0.06 C between 1955 and 1995– Oceans hold 10X heat than what has been used to raise

the global temperature– An increased amount of heat storage in the oceans

preceded all earlier rapid warming• Rise of temperature : Drier climate?

•Satellites that detect and observe different characteristics and features of the Earth's atmosphere, lands, and oceans are often referred to as environmental satellites. •Most environmental satellites have one of two types of orbits: geosynchronous (GOES) or sun-synchronous (POES)

Sea Surface Temperature

• Sea surface-temperature is one important type of data that GOES and POES provide.

• Temperature changes influence the behavior of fish, can cause the bleaching of corals, and affects weather along the coast.

• Satellite images of sea-surface temperature also show patterns of water circulation. Examples include locations of upwelling, characterized by cold waters that rise up from the depths, often near the coasts; and warm water currents, such as the Gulf Stream.

Steve Riser and ARGO lab•3000 free floating package of sensors•Crates a ocean temperature map upto 1500 m depth

Temperatures will rise 0.2 degree Celsius per decade

• Global Sea level rise:– Thermal Expansion = 57%– Melting of glaciers = 28%– Melting at Antarctica and Greenland = 15%

• Melting of Glaciers: – Alaska: 3 C rise in temp in the last 30 years– Glaciers melting at alarming rate– Contributed at least 9% of global sea-level rise– Permafrost melting – decomposition of vegetation rise in CO2– Kilimanjaro – 82% of the snow cap has melted– Very rapid melting of glaciers in the Himalaya and in the Andes

• If all the ice melted sea level will rise by 75m inundating 20% of the Earth’s land area. No Florida!!

• Even a partial melting of Antarctica ice cap will raise sea level by 3 to 6m. Fear of calving from Ross Ice Shelf

• Globally sea-levels rose 10-20 cm in the 20th century – 10X faster than the last 3000 years

• 1 m rise = 1 billion people displaced

NASA image of Greenland Ice melting

Low coastal areas lost 3X more ice due to melting and ice berg formation than high interiors

Area of surface melting across the Greenland Ice Sheet, as inferred from satellite observations of the surface temperature.

IPCC predicts mean sea level to be a meter (100 cm) or more higher than today’s at the end of the 21st century

KEY FINDINGS (National Assessment Synthesis Team)

1. Increased warming

Assuming continued growth in world greenhouse gas emissions, the climate models used in this Assessment project that temperatures in the US will rise 5-10ºF (3-6ºC) on average in the next 100 years.

2. Differing regional impacts

Climate change will vary widely across the US. Temperature increases will vary somewhat from one region to the next. Heavy and extreme precipitation events are likely to become more frequent, yet some regions will get drier. The potential impacts of climate change will also vary widely across the nation.

Global Warming

3. Vulnerable ecosystems

Ecosystems are highly vulnerable to the projected rate and magnitude of climate change. A few, such as alpine meadows in the Rocky Mountains and some barrier islands, are likely to disappear entirely, while others, such as forests of the Southeast, are likely to experience major species shifts or break up. The goods and services lost through the disappearance or fragmentation of certain ecosystems are likely to be costly or impossible to replace.

4. Widespread water concerns

Water is an issue in every region, but the nature of the vulnerabilities varies, with different nuances in each. Drought is an important concern in every region. Floods and water quality are concerns in many regions. Snowpack changes are especially important in the West, Pacific Northwest, and Alaska.

5. Secure food supply

At the national level, the agriculture sector is likely to be able to adapt to climate change. Overall, US crop productivity is very likely to increase over the next few decades, but the gains will not be uniform across the nation. Falling prices and competitive pressures are very likely to stress some farmers.

6. Near-term increase in forest growth

Forest productivity is likely to increase over the next several decades in some areas as trees respond to higher carbon dioxide levels. Over the longer term, changes in larger-scale processes such as fire, insects, droughts, and disease will possibly decrease forest productivity. In addition, climate change will cause long-term shifts in forest species, such as sugar maples moving north out of the US.

7. Increased damage in coastal and permafrost areas

Climate change and the resulting rise in sea level are likely to exacerbate threats to buildings, roads, powerlines, and other infrastructure in climatically sensitive places, such as low-lying coastlines and the permafrost regions of Alaska.

8. Other stresses magnified by climate change

Climate change will very likely magnify the cumulative impacts of other stresses, such as air and water pollution and habitat destruction due to human development patterns.

For some systems, such as coral reefs, the combined effects of climate change and other stresses are very likely to exceed a critical threshold, bringing large, possibly irreversible impacts.

9. Surprises expected

It is very likely that some aspects and impacts of climate change will be totally unanticipated as complex systems respond to ongoing climate change in unforeseeable ways.

10. Uncertainties remain

Significant uncertainties remain in the science underlying climate-change impacts. Further research would improve understanding and predictive ability about societal and ecosystem impacts, and provide the public with useful information about adaptation strategies.

Shift in Predictions from two models

•By 2030, Illinois will have a climate like Missouri’s.•By 2090, it will have a climate like Oklahoma’s.•Resultant shift in ecological communities, agriculture patterns…•Up to 30% of land based animal and plant species might disappear•Hardest hit will be cold-climate-communities e.g., polar bears•Coral Reefs will be hard hit•More Forest fires – more CO2, loss of biodiversity

Green = Canadian modelBlue = Hadley model

Kyoto Protocol• Conference: Dec 1-11, 1997 in Kyoto, Japan• Six Greenhouse gases were targeted (CO2, CH4, NOx, CFC-

substitutes)• Their emission to be reduced below 1990 levels as follows:

– EU: 8%, US: 7%, Japan 6%– The reduction will be done in a 5 year period between 2008-2012– Emission can be traded in global market– Creation of carbon sinks like afforestation can be balanced against

emission– Developing countries to benefit from “clean” technology– The protocol will be open for signature in March, 1998, has to be ratified

by countries producing 55% of the emissions: reached in 2004 after Russia signed it.

– Entered into force: Feb 16, 2005 US pulled out of it in 2001– 187 countries around the world have signed and ratified the protocol.

USA, under the leadership of President Bush has withdrawn from Kyoto Protocol stating it will ‘hurt US economy’ and has made no move to ratify it as of today.

Participation in Kyoto Protocol as of June 2009

Where are we heading to?

USA with 4% of world population produces 25% of CO2

Halting emissions

• California’ s Global Warming Solutions Act• Cut greenhouse gas emissions 25% by 2020

• 10 NE states launched the Regional Greenhouse Gas Initiative (RGGI) in 2007

• cap-and-trade program for C emissions from power plants

Fig. 15-22, p. 371