"Through the animal and vegetable kingdoms, nature has scattered the seeds of life abroad with the most profuse and liberal hand. She has been comparatively sparing in the room, and the nourishment necessary to rear them. The race of plants, and race of animals shrink under this great restrictive law. And the race of man cannot, by any efforts of reason, escape from it.”

““Population increases in Population increases in a geometric ratio, while a geometric ratio, while the means of the means of subsistence increases in subsistence increases in an arithmetic ratio.”an arithmetic ratio.”

An Essay on the Principle of An Essay on the Principle of PopulationPopulation, Thomas , Thomas Malthus, 1798Malthus, 1798

World Population and IndustrializationWorld Population and Industrialization

National Oceanic and Atmospheric Administration National Oceanic and Atmospheric Administration (NOAA)(NOAA)

Laboratory, Mauna Loa, HawaiiLaboratory, Mauna Loa, Hawaii

C.D. Keeling (1928-2005)

Levels of atmospheric carbon dioxide Levels of atmospheric carbon dioxide are increasing from human activityare increasing from human activity

Contributions to the energy budget:

1). Solar Input

2). Atmospheric Absorption

3). Reflection of Light Energy

a). surface albedo, clouds, aerosols, particles b). atmospheric reflection from particles/aerosols return reflected light or IR

4). Infrared (IR) Irradiation (long wavelength, heat loss)

Global Energy Budget and the Greenhouse Global Energy Budget and the Greenhouse Effect:Effect:

a

a

a

a

X Four

b

4

What are the What are the Greenhouse Greenhouse

Gases?Gases?

Carbon Dioxide• most prominent greenhouse gas in atmosphere• emitted by respiration, burning fossil fuels, and deforestation• humans annually add > 30 billion tons of CO2 to atmosphere• In 1996, carbon dioxide world emissions increased by 2.8%. 

– US: increase of 3.3% in CO2 emissions. US continues to emit more than any other country in the world, accounting for 25% of all emissions.

– European Union: increase of 2.2%, much larger than increase of 1.1% in 1995. 

– Eastern Europe had a decreasing rate of -2.4%.  – China's increase in 1996 was 4.7%.

http://www.umich.edu/~gs265/society/greenhouse.htm

Greenhouse Gases: Greenhouse Gases: Not Just CO Not Just CO22!!

Methane (CH4):

• 350-500 million tons added annually

• livestock, coal mining, drilling for oil and natural gas, rice cultivation, and garbage sitting in landfills.

• Atmospheric retention is 10 years, but traps 20 times more heat than CO2.

http://www.umich.edu/~gs265/society/greenhouse.htm

Nitrous Oxide (N2O):

• 7-13 million tons, nitrogen fertilizers, human and animal waste in sewage treatment plants, automobile exhaust; atmospheric retention of N2O is 100 years 

Fluorocarbons:Chlorofluorocarbons (CFCs)- used in aerosol cans, refrigeration• break down the ozone layer, use significantly decreased, banned in US

Hydrofluorocarbons (HFC's)- substitute for CFCs in refrigeration• do not harm ozone layer, but are a greenhouse gas• reduce emissions: recycle coolant, fix leaks, recover the coolant prior to disposal

C.D. Keeling (1928-2005)

Greenhouse Gases from Human Greenhouse Gases from Human ActivityActivity

CO2

CH4

N2O

IPCC, 2007

Sea level rise Sea level rise is mostly from is mostly from thermal thermal expansion of expansion of water, NOT water, NOT from glacier or from glacier or polar ice cap polar ice cap meltmelt

Changes in Changes in snow cover snow cover causes causes changes in changes in heat heat absorption in absorption in a positive a positive feedback loopfeedback loop

Changes in Temperature, Sea Level, and Northern Hemisphere Changes in Temperature, Sea Level, and Northern Hemisphere Snow CoverSnow Cover

IPCC, 2007

Most Aggressive Energy Management PolicesMost Aggressive Energy Management Polices

Least Aggressive Energy Management Least Aggressive Energy Management PolicesPolices

Projection of Earth Surface TemperaturesProjection of Earth Surface Temperatures

Use of Glacial Ice Cores to Determine Use of Glacial Ice Cores to Determine Planetary Temperature: Oxygen Isotope Planetary Temperature: Oxygen Isotope

Analysis in the Vostok (Antarctica) Ice Analysis in the Vostok (Antarctica) Ice CoreCoreVostok research station has operated for over 37 years, now

cooperatively operated by Russian, U.S., and French scientists. Lowest temperature ever recorded −128.6 °F. Ice core drilling gives climate information down to 3310 meters or 414,000 years before present. Ice Core

Vostok Vostok Glacier Glacier SiteSite

Water with Water with 1818O is heavier than O is heavier than 1616O, and “heavy water” tends to remain O, and “heavy water” tends to remain in liquid phase during evaporation, and precipitate first during in liquid phase during evaporation, and precipitate first during condensation. This effect causes depletion of heavy water with condensation. This effect causes depletion of heavy water with increasing cooler climates in increasing latitudes. increasing cooler climates in increasing latitudes. Thus, precipitation formed at cooler temperatures is depleted in Thus, precipitation formed at cooler temperatures is depleted in 1818O O relative to relative to 1616O, and can be used as a measure of the temperature of O, and can be used as a measure of the temperature of condensation. condensation.

1818O is the ratio of stable isotopes of O is the ratio of stable isotopes of oxygen, oxygen, 1818O:O:1616O. It is commonly used as a O. It is commonly used as a measure of the temperature of measure of the temperature of precipitation.precipitation.

Oxygen Isotope Ratios Reflect the Temperature of Oxygen Isotope Ratios Reflect the Temperature of PrecipitationPrecipitation

Petit J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J. Delaygue G., Delmotte M. Kotlyakov V.M., Legrand M., Lipenkov, V.M., Lorius C., Pépin L., Ritz C., Saltzman E., Stievenard M., Nature, 3 June 1999.

Climate & Atmospheric History of the past 420,000 Climate & Atmospheric History of the past 420,000 years years

from the Vostok Ice Corefrom the Vostok Ice Core

Larsen B Ice shelfAntarctica

January 31, 2002

MODIS dataCourtesy NSIDC

February 17

February 23

March 5

1928

2000

The South Cascade glacier retreated dramatically in the 20th century

Courtesy of the USGS glacier group

South Cascade glacier in South Cascade glacier in 1928 and 20001928 and 2000

The glacier has retreated and thinned substantially, leaving a glacial lake in its

place.

A positive feedback loop is a A positive feedback loop is a self-reinforcing system, and self-reinforcing system, and amplifies the effect. In amplifies the effect. In contrast, a negative contrast, a negative feedback loop is self-feedback loop is self-correcting. correcting.

Positive feedback occurs when Positive feedback occurs when a change in one component a change in one component of the climate occurs, of the climate occurs, leading to other changes leading to other changes that eventually 'feeds back' that eventually 'feeds back' to amplify the change.to amplify the change.

Positive feedbacks are a great concern in climate change because Positive feedbacks are a great concern in climate change because small changes may cause large, unexpected changes. small changes may cause large, unexpected changes.

Decreasing Reflection (Albedo) from Loss of Ice Decreasing Reflection (Albedo) from Loss of Ice Cover Creates a “Positive Feedback Loop” Cover Creates a “Positive Feedback Loop”

Resulting in Additional Solar Heat AbsorptionResulting in Additional Solar Heat Absorption

Is Global Warming a Is Global Warming a

Hoax?Hoax? Milankovitch Cycles: invoked to explain changes in temperature as “natural” and independent of human activity.

Milankovitch described changes in the Earth’s movements.

1). Orbital Ellipicity (100,000 Yr cycle) 2). Axial Tilt (or Obliquity) (41,000 Yr cycle)3). Precession (23,000 Yr cycle)

http://www.homepage.montana.edu/~geol445/hyperglac/time1/milankov.htm

‘… ‘… Milankovitch's theory was largely ignored. In 1976, deep-Milankovitch's theory was largely ignored. In 1976, deep-sea sediment cores found that Milankovitch's theory did sea sediment cores found that Milankovitch's theory did predict periods of climate change. Temperature change predict periods of climate change. Temperature change over 450,000 years established that major variations in over 450,000 years established that major variations in climate were closely associated with changes in the climate were closely associated with changes in the geometry (eccentricity, obliquity, and precession) of Earth's geometry (eccentricity, obliquity, and precession) of Earth's orbit. Indeed, ice ages had occurred when the Earth was orbit. Indeed, ice ages had occurred when the Earth was going through different stages of orbital variation.’going through different stages of orbital variation.’ (edited (edited for brevity)for brevity)

Milankovitch Milankovitch Cycles in Cycles in

PaleoclimatesPaleoclimates

http://earthobservatory.nasa.gov/Library/Giants/Milankovitch/milankovitch_2.html

Is Global Warming a Hoax? Is Global Warming a Hoax? Current COCurrent CO22 levels are unprecedented. levels are unprecedented.

Milankovitch cycles do coincide with Ice Ages, are appear to be Milankovitch cycles do coincide with Ice Ages, are appear to be responsible for these climate changes, but current COresponsible for these climate changes, but current CO22 levels exceed the levels exceed the

highest levels over the last 400,000 years by nearly 30%! highest levels over the last 400,000 years by nearly 30%! Historical Historical maximummaximum CO CO22 bearly exceeded 300 ppm bearly exceeded 300 ppm, , we are we are nownow nearly 390 ppm! nearly 390 ppm!

What are the options? What are the options? Carbon Capture and Sequestration?

Biofuel Alternatives?

Solar? Solar?

Nuclear?Nuclear?

Types of BiofuelsTypes of Biofuels

Vegetable OilVegetable OilBiodiesel Biodiesel BioalcoholsBioalcohols (methanol, ethanol, propanol, butanol)

First Generation First Generation BiofuelsBiofuels

BiohydrogenBiohydrogen- for H fuel cells from Methanol

SyngasSyngas- CO + H2 from Biomass (or Coal)

DimethylfuranDimethylfuran (DMF)- from glucose, fructose

Second Generation BiofuelsSecond Generation Biofuels

BiodieselBiodieseldiesel-equivalent processed fuel consists of hydrocarbon chains with

methyl or ethyl estersmade by transesterification of

vegetable oils or animal fats

can be used alone or blended with conventional diesel fuel in unmodified diesel-engine vehicles

Biodiesel Biodiesel ProductionProductionInput: plant or Input: plant or

animal triglyceride animal triglyceride (oil), alcohol, base(oil), alcohol, base

Base-catalyzed Base-catalyzed transesterification transesterification processprocess

Any vegetable oil Any vegetable oil works!works!

Biodiesel production: economical, requires Biodiesel production: economical, requires low temperature/pressure, high conversionlow temperature/pressure, high conversion

http://www.inorganics.basf.com/p02/CAPortal/en_GB/portal/Biodiesel_layout_b/content/Produktgruppen/Biodiesel/http://www.inorganics.basf.com/p02/CAPortal/en_GB/portal/Biodiesel_layout_b/content/Produktgruppen/Biodiesel/Biodiesel/ChemieBiodiesel/Chemie

EthanEthanolol

Basic steps for ethanol production are: fermentation of sugars (yeast), distillation, dehydration.

Some sourses require hydrolysis of carbohydrates to sugars: Conversion cellulose to glucose (acid or enzyme hydrolysis)

Conversion starch into sugar (enzymes).

Production of ethanol from sugarcanesugarcane returns 8 units 8 units of energy for each unit expended !of energy for each unit expended !

Contrast: maizemaize returns only 1.3 units of fuel energy 1.3 units of fuel energy for each unit of energy expended!for each unit of energy expended!

Ethics of Ethanol Production from Ethics of Ethanol Production from MaizeMaize

Current US fuel EtOH production based on starch Current US fuel EtOH production based on starch from maize: from maize:

• Impact on world food pricesImpact on world food prices• Conversion of high quality food into fuel• Maize agriculture requires intense use of energy

& chemicals• Use of premium agricultural land to produce Use of premium agricultural land to produce

maizemaize

Ethics of Ethanol Production from Ethics of Ethanol Production from MaizeMaize

FDA: daily caloric intake 2400 Kcal for 130 lb student. FDA: daily caloric intake 2400 Kcal for 130 lb student.

Combustion of 300 g of ethanol produces about 2400 Kcal, Combustion of 300 g of ethanol produces about 2400 Kcal, one day of calories for a college studentone day of calories for a college student

How far would a car travel on 300g EtOH?How far would a car travel on 300g EtOH?

300g EtOH = approx 0.08 gal (~300 ml)300g EtOH = approx 0.08 gal (~300 ml)Assume 30 mpg (gas)Assume 30 mpg (gas)Decrease mileage by 1/3 (lower energy density of EtOH)Decrease mileage by 1/3 (lower energy density of EtOH)

A car would travel about 1.6 miles with the amount of maize A car would travel about 1.6 miles with the amount of maize that would feed a college student for one day!that would feed a college student for one day!

You could feed an African family or drive a car!You could feed an African family or drive a car!

Disclaimer: Prof. Mulligan made this estimate without Disclaimer: Prof. Mulligan made this estimate without consulting an expert!consulting an expert!

A Better Solution: A Better Solution: Cellulosic Cellulosic BioethanolBioethanol

Ethanol from Waste BiomassEthanol from Waste BiomassCellulose- Cellulose- a structural material that comprises much of a structural material that comprises much of

plant biomassplant biomass

examples: corn stalks, leaves, switchgrass, woodchips, examples: corn stalks, leaves, switchgrass, woodchips, available as agricultural by-products or produced on available as agricultural by-products or produced on marginal land with limited resource inputmarginal land with limited resource input

Current limitation is conversion of cellulose to glucose for Current limitation is conversion of cellulose to glucose for ethanol fermentation.ethanol fermentation.

Cellulosic ethanolCellulosic ethanol would reduce greenhouse gas emissions would reduce greenhouse gas emissions by 85% over gasoline. by 85% over gasoline.

Starch ethanolStarch ethanol reduces greenhouse gas by ~20% over reduces greenhouse gas by ~20% over gasoline. gasoline.

Conclusions:Conclusions: Environmental, economic, and Environmental, economic, and energetic costs and benefits of biodiesel and energetic costs and benefits of biodiesel and

ethanol biofuelsethanol biofuels

Biofuel should provide net energy gain, Biofuel should provide net energy gain, environmental benefits, economically competitive, environmental benefits, economically competitive, be producible in large quantities without reducing be producible in large quantities without reducing food supplies. food supplies.

Greenhouse gas emissions are reduced 20% by Greenhouse gas emissions are reduced 20% by (starch) ethanol and 41% by biodiesel over fossil (starch) ethanol and 41% by biodiesel over fossil fuels. fuels.

Neither biofuel can replace much petroleum without Neither biofuel can replace much petroleum without impacting food supplies. impacting food supplies.

Dedicating 100% US corn & soybean production Dedicating 100% US corn & soybean production meets 12% gasoline, 6% diesel demand.meets 12% gasoline, 6% diesel demand.

Conclusions:Conclusions: Environmental, economic, and Environmental, economic, and energetic costs and benefits of biodiesel and energetic costs and benefits of biodiesel and

ethanol biofuelsethanol biofuels

Biodiesel provides sufficient environmental Biodiesel provides sufficient environmental advantages to merit subsidy. advantages to merit subsidy.

Cellulosic ethanol produced from low-input Cellulosic ethanol produced from low-input biomass grown on agriculturally marginal land biomass grown on agriculturally marginal land could provide much greater supplies and could provide much greater supplies and environmental benefits than food-based biofuels.environmental benefits than food-based biofuels.