Wed. May 4

Don’t forget on-line course evaluation, available until Friday May 6 at https://tce.oirps.arizona.edu/TCEOnline

Final Exam Study Guide will go up on D2L content and on course web page under “Final Exam Guidelines” by Friday.

Current grades will be posted at D2L by Thursday- please review them to make sure we have them correct.

Our Final Exam next Wednesday (May 11), 10:30am-12:30pm (room 308 Kuiper Space Sciences), and it will probably be 100 M/C questions [if that changes, I’ll send out message to everyone].

NASA video about the formation of Antarctic Ozone Hole

Stratospheric ozone: Consequences- increased UV-B reaching surface (because less ozone is present in stratosphere to absorb it) is of greatest concern for our health (skin cancer, cataracts, premature aging, vitamin D), ability of decomposers to operate and release nutrients as they break down organic matter, and health of plants whose photosynthesis and growth may be reduced and damage to DNA increased.

Review of GA6 results from the 12 groups and make-up group. Note video and interactive play at “6 degrees could change the world” on National Geographic

Take home themes from SL:

Earth’s long history is characterized by natural climate change

current difference= rates & people

All else being equal/constant, an increase in Earth’s greenhouse gases (which we definitively know is occurring) will result in an increase in temperature feedbacks are important, but sometimes not well understood

Solar energy is the bomb…………the H-bomb, that is solar fusion is our source of “free” energy; it supports photosynthesis (CH2O and O2); it drives weather; we can harvest its energy as bio-fuels, with wind turbines, as hydroelectric power at dams, solar cells; its energy is available to use in coal, oil and natural gas

CO2 and H2O…….the chemicals you can’t live without; both greenhouse gases keep us comfortable; both necessary for life; both photosynthesis reactants; H2O and heat exchange

Biomass ≈ Energy

biomass is a currency of energy that makes ecosystems run

Fossil-fuel emissions of CO2 are actually quite small compared to Nature’s inputs of CO2 to the atmosphere. TRUE, BUT……………….. they are not being all taken up by terrestrial and ocean sinks, so the CO2 levels in the atmosphere are increasing rapidly

CO2 is not the only greenhouse gas contributing to current atmospheric radiative forcing; CH4 and N2O are next most important

Unintended consequences (cascading effects of population and pollution)

problems of acid rain, tropospheric ozone formation, stratospheric ozone destruction, enhanced greenhouse effect were never part of the “global plan” (or even Dr. Evil’s scheme). Fossil-fuel use has resulted in the amazing progress of the last 100 or so years and amazing technology of today, but unintended consequences are the above problems (note: ozone hole depletion, is largely from freon (CFC) production, a chemical developed for its many useful characteristic to improve our lives)

Resources (metals and fossil fuels) are distributed unevenly around the world because of the influence of plate tectonics and/or past climates and vegetation; this means that often trade is needed even with unfriendly political entities, worldwide demand may drive up prices, and we may have to adjust our personal standard of living

Deforestation and greenhouse gas emissions in Developing Countries are high, but these countries are not necessarily doing things that Developed Countries have not done over the last 150 years to become “developed”

Kyoto signers will lowering GHG emissions except China/India

Trends will continue to rise (CO2, temp, sea levels) even if GHG emissions ceiling is established (scary graph of predicted future CO2 concentration, temperature and sea-level rise that you have seen on a couple of occasions)

Mother Nature undoubtedly still has plenty of surprises in store for us- we don’t know it all! [See radiative forcing above]

Are the high global temperatures of the last decade the warmest temperatures ever on Earth????? (NO! estimated to be 10 degrees higher in Cretaceous)

Mon. May 2

Today is Melanoma Day

As mentioned for GA6, multitasking may not work. In fact, the article says that if you multi-task during this class, your are “more easily distracted and less able to ignore irrelevant information” than others.

Q6 returned and answers given (+4 pt quiz adjustment will be added to your raw score to a max of 27 [the EC question on quiz was worth 2 points])

Course Evaluation is now on-line (until May 6); you should have received e-mail notifications with guidance linking to the evaluation site.

Acid rain often [pH< ~5.2] can effect “cultural heritage”, materials such as metals/marble, aquatic ecosystems, terrestrial systems.

Neutralization (“buffering") of acid rain in carbonate terrain, whereas greatest negative impacts in granitic terrain such as the Northeast and Canada.

Even if SO₂ emissions were reduced, NO_x would still be emitted in large quantities across the US (the highest in Texas and Cal.)

Prospects for worldwide future emissions of NO_x and SO₂; “cap and trade” program of 1995/2000 (establishing a “cap” or allowance for emission from each source, then allowing the selling or trading of allowances when a specific source is above or below its allowance), and its influence on reducing SO₂ emissions from utilities in the US. In 2003 an NO_x Cap and Trade system was implemented by EPA

Stratospheric ozone- the “good” ozone (O₃) is very effective in absorbing incoming UV; it is destroyed in reactions with Cl (freons, CFC)

A strong decrease in stratospheric ozone concentration above Antarctica has occurred since the late 1970s; large increase in extent of ozone depletion above Antarctica- this is “ozone hole” (unrelated to global warming); increased UV-B reaching surface (because less ozone is available in stratosphere to absorb it)

Montreal Protocol in 1987 to stop manufacture and trade of CFCs and other chlorine-containing compounds; we hope to soon see the ozone hole area start to decline in the very near future (but unfortunately some of the largest areas of the ozone hole have been in the first decade of the 21^st Century). The projection is that by 2070, ozone levels above Antarctica will recover to their 1980 levels.

Fri. Apr. 29

GA6, what would you do?

Wed. Apr. 27

Term Paper was handed back.

Looked at scary figure (Fig. 5-2 if IPCC 2001 Synthesis Report) of projections of CO2 emissions and concentrations for hundreds of years into the future and the corresponding changes in temperature, even if emissions are reduced by the middle of the century.

Further consideration of the bet between the Ecologist and the Economist, with respect to cycles of prices driving the results, or maybe the production and problems associated with wastes not being fully included in prices, so they are not rising as fast they would if more waste countermeasures were used.

American Lung Association released its “State of the Air”2011 report today. It gives a list of top 10 cities with high ozone and high particulate emissions. Despite improvements in air quality attributable to the Clean Air Act, about half of the counties in the US suffer from poor air quality and unhealthy ozone levels

Photochemical smog: formed naturally during lightning discharges; formed largely artificially in presence of nitrogen oxides, VOCs and sunlight; more likely to be formed in winter in large northern cities, but plenty of sunlight in cities such as LA, Phoenix and Mexico City to form ozone throughout the year; reduction of urban ozone possible by reducing concentrations of reactants, especially VOCs and nitrogen oxides many fuel pumps now designed to reduce loss of fuel vapors

Auto emissions usually check for particulates, unburned hydrocarbons (“HC” or VOCs), and CO; catalytic converters on automobiles are designed to convert CO to CO₂, VOCs to H₂O and CO₂, and NO_x to N₂; strong oxidizing capacity of ozone can affect respiratory system, degrade chlorophyll in plants, break down rubber products (tires, seals, belts, electrical cords)

Despite the best intent of “The solution to pollution is dilution”, a build-up of air pollutants is favored by very stable atmospheric conditions (reducing vertical movement) associated with temperature inversions

Natural sources exist for emission of nitrogen oxide, sulfur oxide, VOCs (such as terpenes/isoprenes from plants) and even ozone itself (lightning).

Trees and pollution

Acid rain (more properly “acid precipitation” or “acid deposition”)

pH scale; acid rain often defined when pH<5-5.2. The pH when background atmospheric CO₂ dissolves to form weak carbonic acid is about 5.6 (much more acid than neutral pH of 7), and sometimes other natural acids including organic acids can make the pH a little lower; thus rain from “clean” areas is slightly acidic)

The eastern U.S. has the lowest pH of precipitation (highest acidity) because of numerous sources of NO_x and particularly SO₂ gases to the atmosphere.

Mon. Apr. 25

Class discussion about CO2 being a pollutant (as a Supreme Court ruling in 2007 had given EPA the authorization to do, and EPA announced an emissions monitoring program in mid-March 2009). Class came up with several points for and against CO2 as a pollutant, and in the end the class voted about 40 to 6 in favor of CO2 being a pollutant.

News release on residential and commercial buildings and GHG emissions and EPAs competition for buildings and UNC dormitory winner.

Population and Waste- Cascading effects of gas emissions

American Lung Associations “State of the Air” report; in some California cities air pollution is going up, but in many large US urban areas air pollution is going down.

Waste may have ecological and health costs, but historically dirty air is sometimes viewed as evidence of “success”

Primary pollutants (directly out of the smokestack or tailpipe): such as VOCs (volatile organic compounds), nitrogen oxides, sulfur oxides, carbon monoxide (CO) and particulates; Sources dominated by transportation, power generation, industry [all primary pollutants derive from the fuel (for example coal can contain lots of sulfur), except for nitrogen oxides whose nitrogen derives primarily from air N₂]

Secondary pollutants like sulfuric acid, nitric acid, ozone are produced by transformations of primary pollutants SO2, NOx, and NOx+HC, respectively.

Outcome of GA5, the bet between the Ecologist and Economist: Out of the 27 subgroup outcomes (12 regular groups with subgroups plus 3 subgroups in make-up, [only 3 because 2 subgroups of one of the make-ups had same set of 5 commodities]), the Economist won 26 times by an average of $484 in 1990 and $549 in 2000. Why and will this result continue? The commodities are actually less scarce? Fossil fuels have provided a very cheap “gift” source of energy to keep production costs low, when other sources are typically much higher? Price fluctuates up and down quite frequently, and perhaps based on random chance 1980 prices were high but 1990 and 2000 prices were low? Maybe some environmental costs of waste (negatively affecting human health and ecosystems) produced from production of the commodities may not be accounted for?

Fri. Apr. 22

Population and Resources: Water

Clip from Al Gore that you had previously seen

The demise of Lake Chad illustrates how climate change (regional drying) can be important in the face of the demands of a large, growing population (“Lake Chad has been the source of water for massive irrigation projects. In addition, the region has suffered from an increasingly dry climate, experiencing a significant decline in rainfall since the early 1960's.”- NOAA)

The catastrophic effects of water diversion in the Aral Sea, west-central Asia

Massive water collection and distribution network in California and the Salton Sea near us, which has similar problems

Eutrophication- after flourishing growth by addition of excess nutrients to the aquatic system, dieback of the plants/algae results in large demand on oxygen to decompose them, thereby reducing oxygen concentration in water, which is particularly critical for higher organisms in food chain. “Point sources” vs. “non-point sources of pollution” [Mackenzie Fig. 11.17]

Population and waste: GHGs

Sanitary landfill (garbage dump) image with methane collection system

Radiative forcing- our understanding is “very high” that contributions to global warming by greenhouse gases have been important (about 2.5 W/m², versus average total insolation of 340 W/m²), with the order of importance= CO₂ > CH₄ > N₂O and halocarbons (such as Freon).

Radiative forcing by greenhouse gases- our understanding is “very high” that contributions to global warming by greenhouse gases have been important associated with inputs of CO₂, CH₄, and N₂O. The “Global Warming Potential” (GWP) of methane (CH₄) is about 20 times that of CO₂ and the GWP of N₂O is about 300 times that of CO₂.

Anthropogenic sources of

CO₂: industry, autos, land-use change/deforestation, wildfires and biomass burning

N₂O: industry, autos, feedlots, fertilizers, wildfires and biomass burning

CH₄: rice paddies, cattle, natural gas from wells and distribution system, natural gas from coal mines and landfills, wildfires and biomass burning.

Is CO2 a pollutant? The Supreme Court ruling in 2007 gave EPA the authorization to regulate CO2, and EPA announced an emissions monitoring program in mid-March 2009). The Clean Air Act's defines "air pollutant" as emissions (1) that cause or contribute to air pollution, which may reasonably be anticipated to endanger public health or welfare; and (2) that are emitted from numerous or diverse mobile or stationary sources. You will provide ideas about this on Monday

Wed. Apr. 20

Quiz 5 handed back (2.25 quiz adjust points will be added to grade recorded in gradesheet)

Changes in erosion related to land-use change (example the Washington DC area, forest to agriculture to abandoned field to construction/urbanization)

Other Soil Degradation (besides water and wind erosion [Mackenzie Fig. 11.3])

1. Physical (2-3%) excessive compaction, waterlogging)

2. Chemical (12%) salt build-up; stripping of nutrients; excess fertilizers; pesticides/herbicides; wet/dry deposition (acid); industrial wastes/spills

Anthropogenic causes of soil degradation- overgrazing, deforestation, agricultural practices, fuelwood gathering, industrial & waste pollutants (on a global basis, overgrazing, deforestation and agricultural practices dominate soil degradation [Mackenzie Fig. 11.7], affecting about 17% of arable land [Mackenzie Fig. 11.2])

Greenhouse gas emissions from livestock about 18% of greenhouse gas emissions, and it is related to Land-use change, Water, Feed, Ruminant digestion, Solid & liquid waste, Transportation (HSUS full report). Agriculture-related greenhouse emissions would be related to some of these processes as well.

The “Green Revolution” began mainly around the mid-1900s, and has greatly increased agricultural production in the face of rising population (and even diminishing cropland) by: mechanization, pesticides, herbicides, irrigation, new crop strains (breeding and now genetic engineering), and fertilizers. The billion dollar question is whether it can be sustained and adopted by poorer and developing countries (because of cost of fertilizers and pesticides, soil degradation, continued loss of farmland, loss of water for irrigation, and loss of genetic variability/variety). Also, has not worked as well with tropical agriculture as with temperate agriculture in Europe and N. America.

Epic trailer of sizzling new movie starring Sir Biff Wellington about soil erosion catastrophe- Coming soon! I smell Academy Awards and tens of questions about it on the next quiz.

Mon. Apr. 18

Quiz 5 first 20 minutes

Reading of portions of Father Pernin’s first-hand account of the fire catastrophe at Peshtigo

Soils are composed of layers known as "horizons" [Mackenzie Fig. 11.1]: A horizon tends to be organic-rich and materials tend to be leached from this horizon downward; B horizon tends to accumulate materials leached downward, including clays and iron oxide, and in western US carbonate ("caliche") accumulates in this horizon; C horizon is partially weathered horizon below B; western soils have low acidity (they are alkaline) and permit accumulation of carbonates related to evaporation exceeding rainfall, but eastern soils tend to be acidic with no carbonates related to rainfall exceeding evaporation.

Soil characteristics: [a] soil grain size important to working soils, water and nutrients; “loam”-type soils with a mixture of clays, sand, and silt tend to be a better quality soils for crops; [b] type of clays present and cation-exchange capacity important to nutrition

Soil Degradation

Consequences: A- loss of fertile soil (reduced production; more runoff; less water storage in soils; soil harder to till; loss of soil carbon B- impacts on surface water (higher flood levels; reservoirs can fill in with sediments; turbidity (muddiness) can impact aquatic life) Wind erosion can abrade leaves and expose roots

Fri. Apr. 15

GA5 Ecologist and Economist gambling on the future (Make-up 1= Wed. April 20, 11 am, room 330 Space Sciences; Make-up 2= Wed. April 20, 1 pm, room 330 Space Sciences)

Wed. Apr. 13

Term paper handed in.

Tropical forest deforestation carbon inputs to atmosphere compared to fossil fuels and to non-tropical deforestation over the past 150 years, and projections for future (Mackenzie Fig. 10.17)

Deforestation in U.S. in 1800s; Forest was considered inexhaustible resource by settlers and commercial interests moving eastward from East Coast from early 1800s to Minnesota in late 1800s.

Deforestation in U.S.- Great Lakes forest fires of Oct. 8-11, 1871. Forest was considered inexhaustible resource by settlers and commercial interests moving eastward from East Coast from early 1800s to Minnesota in late 1800s. Combination of unusually dry climate, common occurrence of fires and sudden extremely windy conditions resulted in forest fires that burned over 2 million hectares, killing over 1200 people in Wisconsin (Peshtigo-Williamsville) and hundreds more in Michigan (same dates as Great Chicago Fire).

Deforestation was associated with European settlement. After land was logged, slash was left behind. When drought came to the area, what was left behind caught fire and burned what trees were left, and degraded the soil. Both forest, soil, and human resources were lost. To a large extent, the areas that were logged and burned are now forested. This occurred though both afforestation and reforestation. These vigorous, young trees took a lot of carbon out of the atmosphere, and stored the carbon in wood, contributing to the net carbon uptake of US forests since about 1940 in the figure showing history of net carbon uptake from atmosphere or net carbon release to atmosphere from forested areas around the world (Mann/Kump p. 175). This forest regrowth appears to be a major contributor to a sink for some of the excess carbon (i.e., it is part of the missing carbon sink).

Population and Resources: Soils

Historical and ancient historical observations of water/soil perturbations- Attica (Greece) deforestation and grazing 2000 years ago; salinity impacts on agriculture in Mesopotamia and Upper Nile civilizations thousands of years ago; Aswan Dam in 1900s; salinity problems in 1900s in Iraq, Iran, Pakistan, Peru, Argentina; dust from Sahel and Mongolia transported thousands of miles

Soil Degradation [Worldwide Mackenzie Fig. 11.17]

Soil Erosion (57% by water, 29% by wind, Mackenzie Fig. 11.3) in US this erosion averages about 10 tons per hectare

On-site and off-site costs of erosion in US might be $44B annually ($400B for whole world)

Natural events impacting soils= floods, landslides, glaciers, wind, subsidence, drought, waves

Anthropogenic activities impacting soils= mining, agriculture, logging, dams, transportation, subsidence,wells

Mon. Apr. 11

First forests in Devonian (about 400 my ago), but perhaps largest past forests were 300-350 my ago [Carboniferous], 40-100 my ago [Cretaceous], evidence of which is found in coal beds (eastern US coal is mainly carboniferous in age and high sulfur). Although many of the tree species in the Earth’s early forests not longer exist, some descendants persist, many of which are diminutive in size.

Climate can affect type and distribution of forests, (for example “in the last 150,000 years there has been about 10°C change in temperature from interglacial periods 135,000 years ago [and now] versus conditions during the cold glacial “maximum” at 20,000 years ago). The ice age glacial maximum 20,000 years ago resulted in shifting of forest southward in N. America and Europe, and back northward over the past 20,000 years

Modern forests- 4-5 billion hectares world-wide, estimates vary depending on definitions of forests and woodlands

Land-use changes (urbanization; conversion of land to grazing, agriculture; dedication of land to transportation [roads] or energy-flooding-resource concerns [dams/reservoirs])

Major mechanism of land-use change is deforestation

Reasons for deforestation: debt repayment (some woods are a very valuable commodity); resettlement (the only land available to poor may be forested areas that they must work by hand to own); conversion of forest to pasture; international logging; hydropower (impounding water behind dam can inundate forests); fuelwood (cooking and heating)

Dramatic change in global forest cover over the last 8,000 years, with removal of tropical forests especially notable in the old world (paleotropics)

40-50% of tropical forests (S. America, Asia, Africa) have been cut in last 200 years, ie, very rapid deforestation using “slash and burn” methods (India, Indonesia, Brazil have greatest deforestation); tropical forests may have distinct wet/dry seasons related to the position of the ITCZ

Tropical forests (India, Indonesia, Brazil have greatest deforestation, i.e., they are greatest “producers” of tropical wood; Japan, USA and Singapore and now China are biggest importers of tropical wood); tropical forest characterized by great biodiversity, including diversity with height; a genetic “storehouse” possibly containing many new compounds that could become cures and treatments for our illnesses and ailments (“Tropical Pharmacy”); about 30% of all terrestrial NPP; contains 1/3 of all carbon in terrestrial biomass, but soils only contain a small fraction (4%) of all carbon in soils world-wide; [from MacKenzie text: very tight nutrient cycling and retention promoted by mutualistic fungi, dense canopy that inhibits erosion, leguminous (N-fixing) trees]

Fri. Apr. 8

Quiz 4 was handed back

“Rule of 70”= you can determine how long it will take to double by dividing the annual rate of increase into 70. For example, a city whose population is increasing 7% per year will double its population in 10 years (70/7 = 10)

Hypothetical population growth curve stages=> 1. lag, 2. exponential, 3. stationary, 4. death- we are in exponential phase transitioning to stationary over the 21^st Century. World population may eventually top out around 8-10 billion people.

“Carrying capacity”= optimum population that can be sustained in a system/area, and depends on 1-natural resources (incl. food), 2-energy, 3-waste, 4-interactions)

Population density (number of people per unit area; map) is greatest in Japan, Asia and Europe; lowest in Australia.

Population (highest in Asia; world population map) and rates of growth on different continents (highest in S. America Asia and Africa).

Characteristics of populations (these can influence the trajectory of population change): 1-birth rate, 2-death rate, 3-sex ratio, 4-age distribution of populations (age distribution or “population pyramids”-[tutorial]), 5-dispersal (emigration, immigration)

(World Population Prospects, see the 2008 Revision executive summary)

Population and Resources: Forests

Mann/Kump figure of 21^st Century deforestation (p. 175)

Wed. Apr. 6

Phenology used with European grape harvests to estimate growing season temperature over the last 500 years. It has a “hockey stick” shape, with the harvest date getting gradually later and later over most of the period, and then getting earlier on average in the last hundred years.

CO2 emissions from fossil fuels have increased since the beginning of the “Industrial Revolution” around 1800, but only 55-60% of the emissions are represented in the atmospheric CO2 concentration. So where is the rest of the carbon going????

The “missing sink” problem (maybe better called the “unidentified sink(s)” problem) as of early 1990s=> about 6-6.5 GtC are going into atmosphere from fossil fuels per year + another 1.5-2 GtC from land-use change (largely Amazon deforestation) =7.5-8 GtC total; HOWEVER, we can only account for sinks for this excess carbon of about 3.5 GtC in the atmosphere (about 50-60% of the fossil-fuel carbon release) + 2.2 GtC in oceans by inorganic dissolution=5.7GtC. So where is the rest of the carbon (1.3-2.3 GtC) going, ie, what is the "missing sink"?

So where is the rest of the carbon (1.3-2.3 GtC) going, i.e., what is the "missing (unidentified) sink"? answer- probably temperate ecosystems (mid-latitude forests including soils) and tropical ecosystems (forests), with re-growth being a major component of these sinks.

Volcanic inputs of C to atmosphere are large (about 1/10^th of a billion tons), but quite small compared to human (fossil fuel and land-use change) inputs.

Combustion of fossil fuels also affects other element cycles (not just the carbon cycle). An imbalance in the N cycle from anthropogenic activities related to fossil-fuel burning (N₂ burned to NOx) and manufacture of fertilizers from atmospheric Nitrogen. Furthermore, the release of NOx and SO2 gases from fossil-fuel combustion contributes to other world-wide problems such as acid rain (maybe the SO2 emissions from fossil-fuel combustion have also been counteracting the enhanced greenhouse effect, at least up until now)

Coal-oil-natural gas geographic landscape (Mackenzie), N. America has lots of coal and natural gas, but limited petroleum compared to other global regions. The Middle East has relatively little natural gas and coal, but it has most of the oil.

Reserves (Fig. 3 of TecEco web home) of coal, oil and natural gas are enough to sustain us well into future, but their distribution is variable, for example US has large reserves of coal and natural gas, but not oil. Reserves of coal and oil would last about 150 years at current rate of usage [but would potentially triple atmospheric CO2 concentration]. Additional potential fossil-fuel resources as tar sands, oil shales, and methane hydrates could more than double the energy the potential energy compared to coal, but they would also cumulatively increase atmospheric CO2 concentration 4 or 5 times]

Heavy U.S. dependence in 2000 on fossil fuels for energy (about 90%), with only about 10% for alternative fuels (nuclear and renewable); by 2009 it looks like the nuclear and renewable has grown to about 15%.

“Peak Oil 1” [part 2], M. King Hubbert and the possibility that global oil production has/will peaked/peak sometime between 2005 and 2030, and possible consequences.

Population

Thomas Malthus hypothesis of world population growth dating back to the early 1800s - world population will increase disastrously unless checked by war, famine and disease, or “moral restraint”.

“Compounding”= building up of something on the basis of its rate of growth; for example, in a bank account money can earn interest at some annual rate by compounding.

Mon. Apr. 4

Quiz 4 at beginning of period

Carbon cycle box model diagram and primary forms of carbon [atmosphere= CO₂, CO, CH₄, also CO; ocean= HCO₃-, CO₃-, dissolved CO₂; biosphere= CH₂O; lithosphere= limestone (CaCO₃) and kerogen (oil, coal, and finely dispersed organic matter)]

Imbalance of Carbon cycle related to energy production (for transportation, heating, agriculture and other needs of modern society) and consequent rapid transfer of carbon from the lithosphere (where it has been isolated millions of years) to the atmosphere

Fossil-fuel CO₂ release has exponentially increased from less than 0.1 gigatons C (0.1 gigaton [Gt]= 0.1 billion tons = 10¹⁵ g carbon) 150-200 years ago to approaching 8 gigatons C per year of carbon today [8 Gt C= 8 billion tons C= 8 x 10⁹ tons C)].  This CO₂ comes from oil, coal, natural gas, “flaring” and cement manufacture.

CO2 emissions by country- U.S. was number one, but China is now number one.

Atmospheric CO₂.  The rate of increase has been variable over the time period of direct measurement since 1958, related to sources and sinks.  Analysis of gas in ice cores tells us the pre-Industrial Revolution concentration of CO₂ was about 270-280 ppm.

Over last eight-hundred thousand years there is a cyclic rise and fall of CO₂ concentrations from about 190ppm at the peak of the glacial periods to about 275 ppm during “interglacial” periods. Current concentration is the highest it has been in the last million years.

Past CO₂ from carbon cycle models and analysis of leaf fossils and soil minerals (is the 392 ppm CO₂ today the highest in Earth history?)

Last 600 million years=> evidence that most of the period had CO₂ concentrations from about 5 to as many as 18 times the current CO₂ concentration (corresponding “ice house” and “hot house periods”).

Analysis of the statement “fossil-fuel emissions of CO₂ are actually quite small compared to Nature’s inputs of CO2 to the atmosphere, and therefore we need not be concerned with them” in light of the carbon cycle. It does not tell the important part of the cycle, ie carbon formed slowly and stored for tens of millions of years is being rapidly being added to atmosphere; we see large atmospheric concentration increase, because the normal carbon sinks are not sufficiently fast to capture it all.

These emissions have increased since the beginning of the “Industrial Revolution” around 1800, but only 55-60% of the emissions are represented in the atmospheric CO2 concentration. So where is the rest of the carbon going????

Fri. Apr. 1

GA4 on greenhouse gases

Wed. Mar. 30

Student Conservation Association and opportunities for internships in summer or other parts of the year.

Biosphere and carbon cycle

Atmospheric CO₂.  Direct CO₂ measurements (“the most important graph of the 20^th Century”), beginning with Keeling’s measurement site established in Mauna Loa, Hawaii, and providing continuous measurements since 1958; now a world-wide network. Current CO₂ concentration is almost 389 ppm (part per million)- about 33% increase since 1958 resulting largely from fossil-fuel inputs. 

Increase in atmospheric CO₂ concentration has not occurred as a smooth line, but like the teeth of a saw blade, with a maximum and minimum concentration each year. Varying dominance of photosynthesis vs. respiration causes it. This annual “amplitude” (maximum CO₂ to minimum CO₂) change is greatest at high latitudes in N. Hemisphere (“seasonal biosphere”). Why is the amplitude low at the Equator and in most of the S. Hemisphere? (lots of terrestrial biosphere at Equator, but it is not seasonal; little terrestrial biosphere at higher latitudes of S. Hemisphere)

Al Gore clip on the causes of seasonal high and low CO2 (the “zig-zag” ups-and-downs in the Keeling Mauna Loa CO2 curve)

Change of Seasons- seasons may be shifting and expanding as a result of global warming.

Phenology is the study of timing of recurring biologic phases such as budbreak, flowering, first leaf unfolding, leaf fall, migration, hibernation, emergence, and breeding.

Phenology can be linked to carbon and water cycling and energy of biosystems.

Lilacs in US appear to be flowering about 3-4 days earlier now than the first half of the 20^th Century.

A US Phenology network is coordinating and tabulating this information for several species, and other networks exist outside the US.

Climate change and human health- WHO estimates 150,000 excess deaths worldwide related to climate change (from cardiovascular mortality and respiratory illnesses during heatwaves, to altered transmission of infectious diseases and malnutrition from crop failures, to flooding events). Disease spread may be accelerated by warming (like malaria northward), but diseases might sometimes be reduced (like malaria tropical areas that experience reduced precipitation/drying)

IPCC and our knowledge of radiative forcing, as relevant to GA4, which concerns GHGs CO2, CH4 and N2O (and whether the ozone hole contributes to global warming or cooling)

We looked at carbon cycle depiction in Mann/Kump, including reservoirs/pools/compartments=places where element/compound resides (biosphere, atmosphere, oceans, lithosphere), and flux/flow/transfer=processes and rates of movement between reservoirs (other C-cycle representations at Carbon cycle)

Mon. Mar. 28

Writing Exercise #3 was handed in.

For Friday’s GA4 preparation, read EPA pamphlet available in D2L content for week of March 28. Friday, you will also bring in your written scheme for reducing GHG emissions (see GA4 preparation instructions in D2L) and particularly note in the table of the EPA pamphlet the various activities responsible for large inputs of CO₂, N₂O and CH₄

Extinctions

Modern systems have the greatest abundance of species (especially insects) ever, but extinction rates seem to be high. Massive extinctions have occurred in the past, unrelated to human activity. Permian-Triassic extinction event (225 million years ago) the largest of the 6 major extinction in the Phanerozoic (last 600 million years), plus extinction of megafauna about 12,000 years ago, and possible major extinction event in progress over the last 500 years (and growing).

Extinction of dinosaurs (65 million years ago) might have been caused by meteorite impact, evidenced by iridium “anomalies” occurring in sedimentary rocks around the world of that age.

At the Permian-Triassic boundary, evidence from geological record suggests the possibility the extinction was driven by large volcanic eruptions (Siberian traps) or meteorite/comet impact. Evidence suggests loss of land plants and lots of sediments, and many "Bucky Balls" (fullerenes) containing inert gases whose isotopic composition suggests extraterrestrial origin.

Invasive species come from different locations, in many cases different continents, moving via a worldwide network of air and especially sea transportation. Invasive species in US may be responsible for over $100 billion in losses each year. Examples:

Buffelgrass (from Africa, introduced to US in the 1940s; it is a C4 grass meaning it is better adapted to warm summer conditions) and cheatgrass (from Eurasia about 100 years ago; a C3 grass meaning it is better adapted to cool season conditions) a big problem in western states because they capture water and nutrients that would otherwise be used by the native plants. Both grasses also promote wildfire, the consequence of which may be the death of native trees and bushes, and the continued expansion of these grasses. Warming may help buffelgrass to expand because it is better adapted to warm temperatures, and rising atmospheric CO₂ may provide cheatgrass a further competitive advantage.

Zebra mussel were introduced into the Great Lakes from ship ballast in the 1980s, and are now spread throughout the Great Lakes and other nearby river systems including the Mississippi River. ZM’s are prolific filter feeders and filter fine organisms and particles out of the water, which removes the food for some fish species. Also, they encrust pipe taking up water and boats. Climate warming is expected to help them extend their range northward.

Invasive species are a 2-way street, with many Great Lakes species getting into European lakes/seas, and many from outside Africa now causing problems for systems throughout Africa

Fri. Mar. 25

Distribution of organic matter (O.M.) in biomes between the living organisms (mainly plants) and the dead organic matter of soils and litter (Figure from lecture- same password as other password-protected readings) expressed as “dry organic material”. Biomes are typically different in terms of either total organic matter or distribution of organic matter between living and dead O.M.

Global maps (same password as other password-protected readings) of (1) sunlight, water and temperature as influencing growth and productivity, (2) changes in productivity from 1982-1999, and (3) IPCC model projections of vegetation change by 2100.

Biomass is mass of living organisms (= phytomass + zoomass, which is approximately equal to phytomass alone) (mass/volume; mass/area)

Primary productivity is amount of plant matter produced [by photosynthesis] (per area per time)

Gross Primary Productivity (GPP) is total production

Net Primary Production (NPP) = GPP-respiration losses

Biomass in oceans is a miniscule 0.5% of the biomass on continents, but some estimates suggest NPP in oceans is almost 1/2 of NPP on continents. Biomass is needed on continents to provide support to reach light, and therefore the continental biomass is dominated by structural components (CHO- carbohydrates). Marine biomass does not need the structural components, tends to have a higher ratio of proteins to carbohydrates, and have much shorter life spans than terrestrial organisms

Net primary productivity (NPP) = GPP(gross primary productivity) – respiration loss

Respiration loss is about ½ GPP

Aquatic: open ocean- LOW to algal beds, reefs- HIGH

Terrestrial: desert- LOW to tropical rain forests-HIGH and tropical wet lands-HIGH

Coral reefs are like the “rain forests of the ocean” in terms of productivity. They are damaged or threatened by:

1) Hurricanes

2) Humans (excess nutrients, dynamite fishing, aquarium tropical fish trade, overfishing of starfish predators and algae and seaweed eating fish)

3) Change in environment (salinity, clarity, pH, temperature)

The pH change could be toward increasing acidity as more CO₂ dissolves in the water (rising atmospheric CO₂ concentrations)

The current dieback observed in coral reefs may be a result of several factors, often hard to isolate. Coral reefs may be reduced/killed by future warming of the ocean, but coral species are not equally susceptible to the conditions forcing coral bleaching, so the relative abundance of coral species may change and reefs may persist

Aquatic biomes exist in lakes, streams and the ocean. In the ocean, biomes are related to whether they are on the ocean bottom (benthic) or in the water column (pelagic). High biological productivity in upwelling areas and in “estuaries” where fresh water streams encounter coastlines in embayments with highly variable environments of salinity (higher salinity toward bottom and lower salinity at top) and organism associated with tidal mixing and rates of stream flow. Extremely important to commercial fishing.

Wed. Mar. 23

Term Project outlines turned in at beginning of class

According to Mackenzie text, biosystems (ecosystems) are composed of both abiotic and biotic components

These biosystems can be altered by global climate change or other influences/events. For example:

Change in species (abundance or composition; pioneering, invasion and extinction)

Change timing of species development or activity; loss of breeding habitat

Contribute to emigration or adaptive response

Contribute to catastrophic change- wildfire and frequency

Example of fish called “bream” in India, which may be shifting time of spawning to counteract effects of warming waters.

Food chains and food webs (“Energy Pyramid”= “trophic

level pyramid

”= “biomass pyramid”= “ecological Pyramid”)

90% loss of energy going from one trophic level to the next level above it

Energy consequences of "eating low" on the food chain for Western & Asian diets

Biosphere "abiotic components"- climate, nutrients (eg, C,O,H,N,S,etc), sunlight, water

A closer look at abiotic factors of nutrients (eg, major nutrients C,O,H,N,S,P and minor nutrients K, Ca, Fe, Mg- Table from MacKenzie) and climate

Abiotic and biotic components comprise biosystems (ecosystems)

Large, easily identified community units are known as "biomes"; interaction of biota and climate (Fig. 1.9) on a regional scale. Biomes around the world, such as grasslands (Fig. 4.8; table 4.3). These biomes generally conform well to climate regions, where climat is similar (map)

Distribution of organic matter (O.M.) in biomes between the living organisms (mainly plants) and the dead organic matter of soils and litter (Figure from lecture [same password as other password-protected readings]). Biomes are typically different in terms of either total organic matter or distribution of organic matter between living and dead O.M.

Mon. Mar. 21

Mid-term exam was handed back and we went over 2-3 M/C questions per exam page. All answers are at D2L content for week of March 21. Prof. Leavitt made an error in his grading key and the answer to question #43 should be D (not C); if graded incorrectly please give to Prof. Leavitt or Rebecca to correct in gradesheet.

First stage of writing project due Wednesday at beginning of class period. See D2L content week of Feb. 28 for instructions and D2L content week of Mar. 21 for grading information

Writing exercise 3 was handed out today- due next Monday

Events after the midterm

1) Spring Equinox yesterday (March 20), day of year when sunlight comes in vertically over the equator and we have 12 hours of day and 12 hours of night

2) The Japanese earthquake (32km depth off coast of Sendai; Richter magnitude of 9.0; related to convergent plate boundary) and tsunami of Friday March 9.

Final words on Sea Level:

One of the IPCC robust findings is that sea level will continue to rise for many centuries, even if GH gas emissions and GH gas concentrations are stabilized. Uncertainty as to how long Greenland will take to melt; during last interglacial 125,000 years ago more of Greenland melted and consequently sea level was over 3 m higher than today. Greenland ice sheet may melt to size of ice sheet 125,000 years ago in several thousand years, although it may be substantially sooner depending on ice dynamics.

Biosphere (also called “Ecosphere” in our text)

Contains "abiotic components"- climate, nutrients (eg, C,O,H,N,S), sunlight, water

Contains "biotic components"- trophic (nourishment) levels from bottom to top: (1)-primary producers=autotrophs; (2)-primary consumers=herbivores (=heterotrophs); (3)-secondary consumers=carnivores (also =heterotrophs) and additionally a group (4)-decomposers. “Omnivores” may eat at more than one trophic level.

Fri. Mar. 9

No class- students worked on their term writing project

Wed. Mar. 7

Q3 was handed back and discussed; WritingExercise 2 was handed back and discussed.

Miderm Exam, Wednesday, on material from beginning of the semester through today. Study guide is on D2L under Content for week of March 7

Clip from An Inconvenient Truth about ice melting and sea-level rise.

Sea level rise seen at most coastal localities around the world; but not the exact same trends in rise (in fact some show no increasing trend over the last 15 years).

Consequences of sea-level rise

Increased coastal flooding

Increased coastal erosion

Loss of coastal wetlands

Salt water intrusion

Loss of “developed” land

Displacement of people (e.g., Tuvalu islands in SW Pacific now or Beijing/Shanghai/New York in future)

A 1990’s estimate of the cost of a 1 meter sea-level rise in the U.S. was about $400 billion.

The recent and expected rise in sea level is believed to be a consequence primarily of melting of ice on land (glaciers/ice sheets) and expansion of (warming) ocean water (because it decreases density at higher temperature)

Besides global sea level change being dominantly influenced by warming of ocean and melting of permanent ice on land (glaciers/ice sheets) for the neat past and future, other effects on sea level are related to impoundment of rivers behind dams (like Three Gorges Dam, China), or local effects that may be permanent such as subsidence (like Venice) and tectonic changes (faults/earthquakes), or temporary such as hurricanes.

IPCC modeled prediction of global temperature changes of about 1.5 to 6°C by 2100 (2-4°C is most likely), and the mean estimate of global sea level rise is expected to be about 40-50 cm. These predictions represent modeling different scenarios related to fossil fuel usage, economy, population, alternate fuels, etc. Mann/Kump show an estimate of sea level rise of 80-90 cm (or about twice that of IPCC 2007), because models are now better taking into account affects of ice dynamics, such as “calving” of ice sheets into the ocean.

One of the robust findings is that sea level will continue to rise for many centuries, even if GH gas emissions and GH gas concentrations are stabilized.

Effects of a 1 to 6 m sea-level rise at various places around the world can be viewed at this link. [select a region and look at still image for a particular increase in sea level, or run quick time movie by selecting “view”, and then “loop” when it is loaded]

Fri. Mar. 4

Quiz 3 first 20 minutes

“Northwest Passage” was open in late 2007 because of melting of Arctic sea ice (“the lowest area in history” but “history” only refers to the time since satellite observations (began about 1980).

Since 1980, satellite evidence of decline in the area covered by sea ice in the Arctic (but sea ice pattern in Antarctic does not show such a clear trend)

Ice Road Truckers. This Arctic commerce depends on frozen ground (soil and lakes) over which they drive. If the length of time that lakes and soils are frozen is slowly being reduced, the consequence is reduced time available to transport goods by this method.

Methane hydrates (ice with cage-like openings in the molecular structure that hold methane molecules) locked in permafrost and continental shelf marine (ocean) sediments. They could provide fuel for society if carefully managed, but they could contribute an uncontrolled release of large quantities of potent greenhouse gas to the atmosphere as warming melts the ice.

IPCC maps of Greenland and Antarctica showing area where snow/ice is accumulating and where it is declining over the last decade or two. Greenland seems to have a net loss of ice, but the more isolated Antarctica may not be showing any net change.

IPCC prediction this century for loss of glaciers and ice caps (also contributing to rising sea level), increases in thaw depths of permafrost regions, and acceleration of warming in Arctic by “positive feedbacks”.

Feedbacks- positive feedbacks reinforce a change or process that has already take place. For example, if warming by CO₂ is the initial process, then resulting increased evaporation could lead to more water vapor in the atmosphere, which is a greenhouse gas that could further amplify the initial warming; a negative feedback counteracts (opposes) a change or process that has taken place. For example, if warming by CO₂ is the initial process, then resulting increased evaporation could lead to more water vapor in the atmosphere that could contribute to more clouds, which could reflect more incoming sunlight, thereby decreasing temperature and counteracting the CO₂ warming effect.

Summary of Consequences of Arctic warming

Ice/snow Melting: reduces albedo, enhances warming (this is positive feedback)

Melting of permafrost with consequences to

structures and roads

methane release

Northwest Passage and commerce

Melting and contribution to rivers flowing to Arctic Ocean [together with enhanced precipitation at high latitudes], which could influence TH Circulation

Shifting vegetation, tundra => forest (forest has lower albedo than tundra); longer growing seasons

Warming, drying and forest fire increase

Reduced ice in the Arctic Ocean Fall 2007 prompted Russia planted a flag at the N. Pole to claim its resources/territory.

Kilimanjaro - iconic symbol, and representative of global environmental change and our (humankind’s) badness to the planet, but maybe these stories aren’t as they seem.

Wed. Mar. 2

Fires scars in tree rings were used to determine when fires occurred and the climatology associated with fires in Southwest. The first 2 in-class writing exercises relate to the correspondence of low burned forest area to El Niño conditions and high burned forest fire area to La Niña conditions.

Story of rubber ducks- Items inadvertently thrown in ocean (for example from container ships) helping to inform us about ocean circulation. North Pacific “Garbage patch”. You can even go on a cruise this summer to see it!!! (NPR Moby Duck)

Cryosphere

Videos from Al Gore’s AIT topics on the melting mountain glaciers, Arctic and Antarctic. Solar energy and albedo changes were a big element related to the Arctic clip as related to “positive Feedbacks”- positive feedbacks reinforce a change or process that has already take place. In the polar ice example, warming by CO₂ is the initial process, after which the north pole ice cap (sea ice) shrink and albedo becomes lower (more sunlight absorbed by Earth’s surface when the white ice/snow is lost, which in turn leads to more heating of the poles. In other words, the melting of the ice cap amplifies the initial warming- this is a positive feedback.

“Northwest Passage” was open in late 2007 because of melting of Arctic sea ice (“the lowest area in history”), but headlines of being open for “for first time in history” were misleading because it is based on satellite observations.

Permafrost- permanently frozen ground. Often surface may thaw to shallow depth in summer but deeper layer of permafrost will remain frozen all year. If melted, it caused numerous engineering problems. The “drunken forest” in AIT occurred where permafrost was melting; also the sinking of buildings, roads and pipelines where permafrost is melted.

Mon. Feb. 28,

Make-up times for GA3: Wed 2-2:50 (March 2) Room 330 Space Sciences and Thursday 12:30-1:20 (March 3) Room 330 Space Sciences; Anyone who missed GA3 is welcome to come to the make-up, regardless of whether you had a valid excuse or not. Please estimate how many pound of beef you eat per week, and how many pound of non-beef meat you eat per week and bring these numbers along with a CALCULATOR, to the make-up. (full instructions under D2L content for week of Feb. 21) Don’t be Late!!

Writing Exercise 2 was handed in

Writing project (see D2L content for week of Feb. 28 or the syllabus) was unveiled, with lots of possible topics given, as well as deadlines, requirements and formats. If you come up with a global environmental change topic other than related those given in the instruction, you should pass it by Prof. Leavitt or a TA to make sure it is ok.

Ocean circulation- surface ocean current on the eastern side of the south Pacific Ocean Basin (eastern current of the S. Pacific gyre) normally brings cool water from the Antarctic northward. That current promotes “Upwelling” of nutrient-rich deep water along the S. American coast, which supports food chains/webs, which can in turn be influenced by ocean/atmosphere conditions.

El Niño and currents in S. Pacific

El Niño tends to recur in irregularly from 2-7 years, and strength varies among events.

It is related to atmospheric and ocean circulation in the tropical Pacific Ocean (see diagrams in textbook and http://www.pmel.noaa.gov/tao/elnino/nino-home.html)

Evidence for El Niño events= (1) Thick, warm water pooled on east side of Pacific, (2) Reduced upwelling off S. American coast and fishery crash, (3) SOI (Southern Oscillation Index) negative (the atmospheric pressure at Darwin is greater than Tahiti), (4) Westerly winds (west to east winds) in Pacific near equator, (5) High precipitation in Ecuador/Peru; Low precipitation in Australia/Indonesia

During La Niña events conditions are generally the opposite of those listed for El Niño evidence. We are currently in a fairly strong La Niña, with lower precipitation this winter in southern Arizona than average (although maybe it is not warmer than average as we would expect)

“Teleconnections” are the influence of El Niño outside of the confines of the Pacific Ocean Basin; these include statistical correlations of El Niño with climate of diverse locales such as climate effects in the US Southeast, eastern S. America (including the Amazon Basin), India, and Africa; see teleconnection maps in Mackenzie and Mann/Kump.

“ENSO” (El Niño/Southern Oscillation) and tropical wildfire- during El Niño events, there is increased precipitation along Peru and Ecuador (but precipitation is reduced in Amazon), so it is ripe for fires just like the rainforests in Indonesia during El Niños (the opposite occurs during La Niñas)

El Niño has tended to be more frequent and stronger after the mid-1970s, whereas La Niña tended to dominate in the decades prior, suggesting some decadal periodicity; these cycles on longer scales (25-30 years) may influence Pacific climate and teleconnect elsewhere, including PDO (Pacific Decadal Oscillation)

Consequences of “El Niños of the Century” (1982-83 & 1997-98) in the western US, such as flooding and filling of water reservoirs

IPCC says warming will contribute to shift of warm pool to east in Pacific during the 21^st Century, but models do not agree about whether frequency and strength of El Niños and La Niñas will change.

Fires scars in tree rings were used to determine when fires occurred and the climatology associated with fires in Southwest. The first 2 writing exercises relate to the correspondence of low burned forest area to El Niño conditions and high burned forest fire area to La Niña conditions.

Fri. Feb. 25

Group Activity 3- beef

Wed. Feb. 23

Writing exercise 1 was handed back

Preparation for GA3, see Feb. 21 ClassNotes

Densest water forms in far North Atlantic and far South Atlantic areas of ocean, where there are cold temperatures and salinity greater than 35permil (35 parts per thousand=the average of ocean water)

The excess salinity in N. Atlantic contributes to sinking of dense water that then moves as a deep current through the S. Atlantic Ocean, Indian Ocean and Pacific Ocean before rising and returning as a warm-water surface current back to the N. Atlantic (to replace water that has sunk to the deep currents)

Thermohaline circulation transports heat and salinity (salt) as nature tries to even out these imbalances around the world ocean.

There may have been times in the past, and maybe in the future, where the thermohaline circulation could slow or stop, with important climate consequences. Younger Dryas was an abrupt return to cold conditions about 12,000 years ago (10,000 radiocarbon years), after the last ice age appeared to end; evidence is seen in calcium concentration of ice cores; it was likely caused by a shift in meltwater discharge from the Gulf of Mexico to the N. Atlantic as melting N. American glaciers retreated. It appears to have been teleconnected world-wide, probably by its influence on suppressing thermohaline circulation. This is an example of “abrupt climate change”

Story of tree rings and Younger Dryas in central N. America from NW Indiana

Evidence for freshening of N. Atlantic (from precipitation or melting ice) in recent decades.

IPCC report predicting a 25% slowdown of thermohaline circulation by the end of the century, but no shutdown; beyond that it is uncertain.

Ocean circulation, surface ocean

Surface currents- driven by wind; flow in semicircular patterns known as "gyres"; high pressure drives air circulation that drives gyres; direction of circulation is different in the North and South hemispheres.

Also, the surface warm return currents of thermohaline circulation such as the Gulfstream move water at and near the surface. Gulf Stream provides mild climate of British Isles and Scandinavia (compared to more extreme climate of Virginia to Massachusetts where first European settlers arrived)

“Upwelling” of nutrient-rich deep water along S. American coast supports food chains/webs (fisheries along coastal Peru are dependent on upwelling); the food web is supported at its base by photosynthesis (CO₂ + H₂O in the presence of chlorophyll and with energy from sunlight => CH₂O + O₂). The CH₂O product is organic matter that is important both with respect to mass and stored energy. [Respiration, combustion, and decomposition are mechanisms that represent the reverse reaction: CO₂+H₂O => CH₂O + O₂]

Mon. Feb. 21

Quiz 2 was handed back and answers were discussed (+1.5 quiz adjust will be added to your raw score). “Tipping Point” was the wrong answer to question 3, but it relates to one of your readings that we did not cover in class. No one knew the meaning of it, so we will have a question about it on Quiz 3.

Preparation for this Friday’s GA3. Estimate how much beef (or other meats) you eat per week, and bring calculator. Also read short articles on beef nutrition fact sheet and Worldwatch article “Is Meat Sustainable” (full preparation instruction under content on “Week of Feb. 21”)

Section 52 students start a new Discussion today on weather extremes and variability.

Kepler telescope devoted to finding planets around other stars in our galaxy came out with an estimate a few days ago of perhaps 500 million “goldilocks” planets in our galaxy.

Humidity in the atmospheric reservoir of the water cycle- Warmer air can “hold” more humidity- an increase in global temperature could result in more evaporation and more water vapor in the atmosphere, but relative humidity would not necessarily change because higher temps would mean more water-vapor holding capacity. Try USA Today and USA Today2 for more explanation.

IPCC (Intergovernmental Panel on Climate Change) 2007 report gives us information about past climate variability and future changes. With global temperature increase, the hydrologic cycle can be affected. For example, heat waves/drought are expected to be more frequent and last longer in the future, with some evidence of increased drought in the tropics/subtropics. Precipitation will change but not necessarily uniformly- in some places, more precipitation is forecast and others less. Evidence of reduced N. Hemisphere snow cover in the last 25 years

With global temperature increase, the hydrologic cycle can be affected. Precipitation will change but not necessarily uniformly- Maps showing prediction of precipitation in 21^st Century (see p. 89 of Mann/Kump), Maps showing change (increase and decrease) in precipitation during the 20^th Century, and Maps showing change (increase and decrease) in number of days of precipitation. Even in some areas of increasing precipitation, the number of days of precipitation has decreased, i.e., fewer precipitation events but they are larger in quantity of precipitation.

Deep-ocean currents (and the “Ocean Conveyor Belt”) require dense water to start cycle by sinking

Dense water achieved by (1) cooling or (2) increase in salinity

Short Writing Exercise 2 was handed out toward the end of the period (due next Monday). It is related to writing more economically and more interestingly by reducing usage of there is, there are, there will be, there were, etc.

Fri. Feb. 18

Writing exercise 1 turned in today

Demo of surface tension of water with razor blade and paperclip.

Properties of water (<= click for diagrams) cont’d

More salt and polar compounds can be dissolved in water at higher temperature, but non-polar gases are less soluble in water at higher temperatures.

A measure of the amount of material dissolved in water is TDS (total dissolved solids)- it ranges from 0 parts per million (pure distilled water) to Tucson water (300-700 ppm), to ocean water (35,000 ppm equivalent to 35ppt), to Dead Sea (200,000 ppm); water quality may also depend on what is “in” the water (for example low TDS but high arsenic or PCBs could be a problem that electrical conductivity alone could not detect)

Pattern of latitude precipitation- highest at equator, and secondary peaks at about 45-55° latitude; minima at about 30° and 90° latitude (related to solar heating and general circulation) (diagram in Mackenzie)

General pattern of evaporation with latitude- greatest at low latitudes and least at high latitudes (diagram in Mackenzie)

Groundwater, aquifers and subsurface flow of water in the water cycle

Streamflow (runoff) can be measured with stream gage instruments back into the 20^th Century, but tree rings can be used to reconstruct streamflow back hundreds of years.

Wed. Feb. 16

Quiz 2 first 20 minutes

Still waiting from group leaders of groups 2 and 12 to complete their GA2 assignment.

Writing Exercise 1 due Friday- (1) Don’t use while, if you mean although or whereas (while has element of time); (2) Don’t use due to if you mean because of or caused by; (3) Don’t use since if you mean because (since has element of time); (4) that is more specific to one thing just referenced in a sentence, whereas which encompasses broader ideas or a less specific reference and is usually preceded by a comma. In all formal writing for the remainder of the semester, you will lose credit for each occurrence of one of these mistakes (less for that/which because it is rather tricky sometimes).

Clip from An Inconvenient Truth about disturbances of the Hydrologic Cycle, hence the value in knowing something about it.

Properties of water (<= click for diagrams) cont’d

Specific heat- 1cal of heat energy will raise temperature of 1 g of water 1°C. Most other substances, eg, metals, sand, have lower specific heat.

As water cools density increases to a maximum density at 4°C (39°F); with further cooling density decreases- this contributes to lakes that freeze from the top down in the winter (rather from the bottom up)

Water can dissolve many different types of substance such as salts (like table salt), polar compounds (like carbohydrates and proteins), and non-polar substance (like CO₂ and O₂)

More salt and polar compounds can be dissolved in water at higher temperature, but non-polar gases are less soluble in water at higher temperatures.

Mon. Feb. 14

GA2 Make-up- Tuesday 11am, room 104 W. Stadium (conference room); COUNTRY= North Korea

We considered Benford article related to “geoengineering” to reduce or prevent harmful global warming effects from enhanced greenhouse effect. Students came up with some of the ideas from article such as painting roofs white, adding SO2 (converted to sulfate SO₄^--) to troposphere and stratosphere, the “geritol” solution of adding iron to the ocean, and planting trees. One question on Quiz 2 will be related to these or other ideas from Benford.

Climate is weather averaged over time (usually about 30 years), and models forecasting global change compare the average of at least 20-30 years of their forecast to the current conditions for 20-30 years. This is seen in modeled global temperature map comparing predicted temperature change for 30 years at the end of the century to 30 years at the end of the 20^th Century.

Hydrological cycle is expected to change associated with global climate changes, so some areas may become wetter and others drier (see Mann and Kump, p. 124-125) (past “superdroughts” contributing to downfall of Toltec and Aztec empires revealed by tree rings, indicating the sensitivity of the Southwest and Mexico to drought, featured in Scientific American article)

Intro to water cycle (driven by solar energy)- reservoirs where water resides, represented by the amount [mass, volume] present), and fluxes represented by movement of water between reservoirs [mass per time, volume per time]) Most water in oceans, most fresh water locked up in ice caps, more fresh water in groundwater than surface water. Fluxes between water reservoirs, eg, runoff is the primary direct flux between continents and ocean, or precipitation transfers water from atmosphere to land or ocean.

Properties of water (also this link)

Strong covalent bonds between hydrogen and oxygen (sharing of electrons to “fill” electron shells/orbitals)

“Polar” water molecule (which has a “positive” side and “negative” side) promotes cohesion, adhesion, capillary rise (water pulls itself upward in small tubes because of cohesion and adhesion), and surface tension

Handed out writing exercise due on Friday Feb. 18 at class time:

(1) Don’t use while, if you mean although or whereas (while has element of time); (2) Don’t use due to if you mean because of or caused by; (3) Don’t use since if you mean because (since has element of time); (4) that is more specific to one thing just referenced in a sentence, whereas which encompasses broader ideas or a less specific reference and is usually preceded by a comma.

Fri. Feb. 11

GA 2 Water Resources around the world

Wed. Feb. 9

Satellite photos of storms and weather maps with High and Low Pressure systems and fronts.

Earth’s “radiation budget” (Mackenzie)- 30% of incoming solar radiation is reflected immediately back to space ("albedo") by Earth's surface and atmosphere; for the fate of the 70% absorbed: 45% is absorbed by the Earth’s surface yet the Earth’s surface does not get warmer and warmer. This is because much of the energy absorbed at the Earth’s surface gets transferred to the atmosphere by latent heat (evaporation) and sensible heat (conduction of heat you feel) by “thermals”. Greenhouse gases (GH gases) absorb and re-radiate electromagnetic radiation, maintaining the warmth of the Earth-atmosphere system. This radiation budget relates to how the Earth was, is, or can be cooled or warmed.

Atmosphere absorbs some wavelengths of terrestrial and solar radiation. Incoming solar radiation has much of its UV radiation removed by oxygen and ozone; outgoing terrestrial radiation is absorbed by greenhouse (GH) gases such as water vapor and CO₂.

Our detailed definition of the greenhouse effect- the atmosphere is “transparent” (ie, it does not absorb) to much of the incoming solar radiation (like the greenhouse windows), but greenhouse gases effectively absorb many wavelengths of the outgoing terrestrial radiation and prevent the energy from escaping to space (like greenhouse windows keeping heat energy in the greenhouse). Greenhouse gases, particularly water vapor (H₂O) and carbon dioxide (CO₂) contribute to the “greenhouse effect” that has maintained relatively mild temperatures on our planet for billions of years. The “enhanced greenhouse effect” from rising greenhouse gases like CO₂ is the concern behind Al Gore’s AIT, the National Geographic Special “6 degrees”, the Kyoto Protocol, etc. The garden-variety greenhouse effect is a good thing that has served Earth well for billions of years, without which the Earth’s average temperature would be 33ºC colder; it is the enhanced greenhouse effect that is the major global change problem we are currently facing.

“Enhanced greenhouse effect” is of concern because very large recent increases of greenhouse gases such as CO₂, methane and N₂O, all of which varied little between 10,000 years ago and about 200 years ago, but have since increased drastically

Weather- conditions in the atmosphere (temperature, humidity, atmospheric pressure, winds) now or at some other specific time. (a weather map depicts aspects of weather)

Climate- weather measured over several decades, usually at least 30 years. Average annual temperature of a location, average temperature on Feb. 15 would be examples of climate measures, deviation of current temperature from the long-term average would be a comparison with climate

The assigned-reading article by Benford proposes some “adjustments” of our atmosphere (and oceans) to counteract global warming. What are these adjustments? Make sure you have read this by Monday.

Mon. Feb. 7

Begin preparation for GA2

We discussed answers to homework exercise involving different temperature scales and global atmospheric circulation associated with convection cells in the atmosphere.

Intro to general circulation based on homework exercise- Deserts, storms, surface wind directions, horse latitudes, doldrums, and sailing to “New World”

Earth’s “radiation budget”- 30% of incoming solar radiation is reflected immediately back to space ("albedo

”) by Earth's surface and atmosphere; for the fate of the 70% absorbed: 45% is absorbed by the Earth’s surface yet the Earth’s surface does not get warmer and warmer.

High and Low Pressure systems, and movement of air around them (clockwise and counterclockwise in the N. Hemisphere, respectively).

Demonstration of 4 atmospheric gases (N₂, H₂O, CO₂ and O₂), some in unusual (cold) forms. Experiment to determine if one of the liquids in the test tube was N₂, H₂O, or O₂. Experiment with balloon and liquid nitrogen.

Fri. Feb. 4

Incoming solar radiation is most “concentrated” near equator, and most “dispersed” near the poles because of the angle of incidence. Transfer of energy by radiation, conduction and convection, all of which relate to heating of Earth-Atmosphere system and transfer of excess heat from ground to atmosphere and from low latitudes to high latitudes.

A little more on general circulation (Hadley Cells, rising/sinking air, etc) in regard to prevailing surface winds and their influence by the Coriolis effect (another link), which deflects wind to right in N. Hemisphere and to left in S. Hemisphere

Electromagnetic radiation is means by which energy is gained and lost by the Earth.

Electromagnetic spectrum (pdf) subdivided into categories of radiation defined by wavelength (l).

“Rules of Electromagnetic (EM) Radiation”- (1) The hotter the object, the shorter the wavelength of peak radiation (Wien’s Law determines the peak wavelength, and the temperature of any object will determine the wavelength), (2) Shorter wavelengths have greater energy, (3) Energy emitted as EM radiation increases as the 4^th power of an objects temperature, (4) Objects emit visible light (reddish glow) as objects reach a temperature of about 550-600C.

Wien’s Law (l_peak=2880/T_K) determines the peak wavelength and at Earth’s temperature (15ºC, 288K) the peak of emitted radiation is at 10mm (infrared), whereas at Sun’s temperature (6000K) the peak of the emitted radiation is at 0.5mm (visible).

Last 20 minutes= Informal contest to see which 1/3 of the class would be able to save the polar bears (NON-Trivial Pursuit type of quiz game)

Wed. Feb. 2

We live in the bottom of a "sea" of air, with greatest atmospheric pressure at the Earth's surface (at sea level)

Temperature structure of atmosphere-- averaged over the whole planet and over the whole year, we see temperature change as we go upward into the atmosphere as follows:

Average surface temperature is +15°C (Earth’s surface would be -18°C if no greenhouse gases were present)

As you go further upward, temperature decreases to about -57°C at a height of 10 km, which is the top of the lowest atmospheric layer (known as the “troposphere”, in which we live)

“troposphere” in which we live, contains nearly all weather on Earth, and has abundant vertical and horizontal air motion (clouds indicate some of this vertical motion)

The thin layer above the troposphere is called the tropopause where temperature remains constant as you continue to go upward

As you continue further upward, temperature then starts to warm in the next layer (“stratosphere”, contains the ozone layer where absorption of solar ultraviolet radiation contributes to the increasing temperature, and air motion is dominantly horizontal) until it is a balmy 0°C at the top of the stratosphere at 50 km

Record of rising average global temperature since 1850 (from Kump/Mann) based on instrumental measurements; photos of measurement of temperature- thermometers in instrument shelters

Some examples of poorly sited instrument shelters- IPCC 2007 report states that the upward trend in instrument-based global temperatures occurs regardless whether sites with urbanization are included or excluded from the mean global record.

Temperature scales (°F, °C, K) and conversions between them (complete Homework 4 by Monday-it will not be turned in)

Earth-Sun orientation as Earth orbits around sun. Tilt of Earth’s rotational axis contributes to different seasons, related to where/when sunlight is incident most directly on the Earth’s surface

ITCZ- intertropical convergence zone (heat equator) moves north and south of geographical equator depending on season (it occurs where sunlight is most direct).

Intro to general circulation- a consequence of greater heating from sunlight at the Equator than at the poles. Global air circulation follows convective patterns where air rises at 0° and 60° latitude, and sinks at 30° and 90° latitude. “Hadley Cell” is convection cell closest to Equator where air rises and sinks at 30°N and 30°S latitude. The return flow of wind along the Earth’s surface to replace the rising air results in easterly winds (east to west) from 0-30° latitude, westerlies from 30-60° latitude and easterlies from 60-90° latitude.

Homework 4 exercise to draw vertical and horizontal circulation (convection cells), as well as predominant wind directions associated with various latitude bands (by Monday).

Mon. Jan. 31

Answers to Q1 were discussed; 19.2 was average; +1 “quiz adjust points” will be added to your raw score in the master gradesheet.

Make-up opportunities for GA #1- Wed 11-12, room 330 Space Sciences; Prepare for group activity by researching composition of TITANIUM following the instructions provided and bringing in at least 2 printed/photocopied pages of relevant information. 14 Grand Challenges for Engineers for the 21^st Century- several of which directly relate to topics of this class.

Short oil video at beginning of class related to earth resources and rising price of resources, (metals and) petroleum

Review Earth timeline of major natural global changes, including origin and abundance of life; early “weak sun” and the role of greenhouse gases; cyanobacteria (stromatolites

) and changing atmospheric oxygen concentrations; banded iron formations (BIF) representing precipitation in early oceans of Fe²⁺ with oxygen liberated by photosynthesis, thus preventing an early build up of oxygen in the atmosphere until all of the Fe²⁺ was “used up”. Fe²⁺ would be considered a “sink” for oxygen, as the first oxygen form was rapidly consumed by forming Fe-oxides

Today’s atmosphere dominated by nitrogen (78%), oxygen (21%), argon (1%) and “trace gases”, i.e., it is an “oxidizing” atmosphere. 4.6 billion years volcanic gases were being emitted containing H₂O (dominant), CO₂, SO₂, H₂S, HCl, H₂, CH₄, and N₂ during initial "outgassing" of Earth's interior, i.e., a “reducing” atmosphere. H₂O condenses to form oceans; H₂ escapes to space; SO₂ and CO₂ readily dissolve in ocean and precipitate as gypsum and limestone, respectively; photosynthesis builds up O₂ (after BIF oxygen Fe²⁺ “sink” that removes oxygen became saturated), although “photodissociation” of water vapor molecules in upper atmosphere also produces small quantities of H₂ and O₂. Photosynthesis is a process/mechanism (“source”) that produces oxygen (CO₂ + H₂O => CH₂O + O₂ in the presence of chlorophyll and with energy from sunlight). We will usually refer to CH₂O as “organic matter”

Reverse reaction of photosynthesis is respiration/combustion/decomposition

Important properties of the trace gases (list and properties in Homework 4 [do not turn in])

“Sources” (mechanism/process for gas getting into atmosphere), “sinks” (mechanism for removing gas from atmosphere) and importance of some major and trace gases; for example, H₂O and CO₂ are most important greenhouse gases on Earth. Respiration (the reverse reaction of photosynthesis) is a mechanism (sink) to remove oxygen from the atmosphere (CH₂O + O₂ => CO₂ + H₂O). The same equation can likewise represent combustion processes that also remove oxygen from the atmosphere (sink).

Water vapor (H₂O) and carbon dioxide (CO₂) are the 2 most important greenhouse gases on our planet.

Fri. Jan. 28

Group Activity 1- Mineral Resources

Wed. Jan. 26

Quiz 1- first 20 minutes

Students have some preparation to do for Group Activity 1 before class Friday; You can find what group you are in (and the instructions for the research that you need to do prior to class) under D2L content and on links in the course homepage (accessible from D2L).

Plate tectonics is directly related to location of natural resources, the extraction and processing of which can affect atmospheric chemistry, hydrologic cycle, etc, natural emission of gases.

Chemicals are heterogeneously distributed across the Earth’s surface. In many cases, besides earthquakes and volcanoes, the location of ore deposits of specific metals/elements is related to plate tectonic and plate boundaries. The richness of metal resources of a country is dictated by their current and past position with respect to plate tectonics ore-forming processes, and other ore-forming processes such as related to climate. Ore deposits of some elements may be as much related to climate as plate tectonics. Table of important elements, their uses, and sources- Note the USA is only a primary source for a few of the elements.

Raw resources are very important to our society, but extraction and processing has its costs (with example of computer chips, in terms of energy, water and waste, which can contribute to environmental problems and global changes).

The price of copper (historical graph) and oil over the last 6-8 years was considered.

Video of innovative Nepal fuel, which is relevant to Smith’s “In Praise of Petroleum”.

Mon. Jan. 24

Your summary of Lemonick article in Scientific American with your personal thoughts is due in class on Wednesday, Jan. 26 (1-page, double-spaced).

The quiz Wed will be given in the first 20 minutes of class, with lecture to follow as is customary. Sample quiz 1 is on D2L with answers soon to be posted.

We will have Group Activity 1 on Friday and instructions will be sent to everyone and to group leaders on Tuesday. Group lists will shortly appear on D2L and the course webpage- see what group you are in.

Origin of Solar System (cont’d)

Matter was distributed in the solar system such that the internal 4 planet are more dense and rocky “terrestrial” planets and the outer “Jovian” planets are lower density, “icy” planets composed of lighter elements/frozen gases. There are also satellite planets (moons) orbiting around many of these planets, such as Titan. [not in lecture: over 400 other planets have been observed around other distant stars, but most are quite different than ours (hotter and much, much larger!)]

Newton’s Laws

1^st- Every object persists in a state of rest or in uniform motion in a straight line

unless acted on by an external force to change that state.

2^nd- The change in velocity (= acceleration) with which an object moves is

directly proportional to force applied and inversely proportional to the

mass of the object (a=F/m)

3^rd- Every action has an equal and opposite reaction (conservation of momentum)

Law of Universal Gravitation- any and all objects exert a force of attraction between them proportional to the product of their masses and inversely to the distance between them squared. (F= G x (m₁ x m₂)/r²) (also see Family Guy clip for humorous example)

Newton’s Law of Universal Gravitation further explored with astrological examples of gravitational force exerted on you at birth (by closest star other than sun, and doctor).

Structure of the Earth (heterogeneous distribution of chemicals with depth=layers)

Earth’s core is made predominantly of iron and nickel (like some meteorites). The mantle layer above the core is primarily magnesium (Mg) and iron (Fe) silicate (Si and O) rock, and the crust on the surface is composed of silicate rock with less Fe and Mg and more K, Na and Al.

During early stages of Earth history, our planet was at least partly molten resulting from heat of collisions and gravitational potential energy converted to heat energy (decay of radioactive elements was also important source of heat over all of Earth’s history)

During this early period, Earth began to “differentiate” into layers with heavier material “sinking” to interior and lighter material “rising” to surface. Consequently Earth’s core is made predominantly of iron and nickel (like some meteorites). The mantle layer above the core is primarily magnesium (Mg) and iron (Fe) silicate (Si and O) rock, and the crust on the surface is composed of silicate rock with less Fe and Mg and more K, Na and Al.

Differences in chemistry among layers (for example low SiO₂ in mantle and higher in

continental crust, and more Fe in mantle and less in crust) is consistent with Earth’s “differentiation” into the layers early in its history. Continental crust is referred to as having a granitic composition (K,Na,Fe,Al,Si,O); oceanic crust a basaltic composition (Mg,Ca,Fe,Al,Si,O). The ocean crust is also called “mafic” (dominated by Mg and Fe), whereas the mantle is ultramafic in composition.

Crust and rigid upper mantle constitute the “lithosphere”. The lithosphere rides over the portion of the upper mantle (asthenosphere) that flows (heat from Earth’s interior leads to convection processes in the asthenosphere). The plates move (cm per year) and interact with each other in a dynamic system known as “plate tectonics”.

Plate tectonics and types of plate boundaries (plates colliding = “convergent” boundary; plates moving apart = “divergent” boundary; plates sliding past each other = “transform” boundary). Caused by convection (flow) in upper mantle. Contributes to lateral heterogeneous distribution of chemicals across the Earth’s surface. Boundaries associated with earthquakes and volcanoes.

Fri. Jan 21

Homework #3 assigned; to be turned in Wednesday Jan. 26 as hard copy- Write a 1-page double-spaced summary of the content of the Lemonick article in Scientific American. Please feel free to include any of your personal views in this writing. We talked about some of the elements of the article in class, related to Judith Curry’s research into hurricane intensity, interaction with skeptical bloggers, uncertainty in data and models, “groupthink”, “fortress mentality”, and predictions of sea-level rise

First Quiz next Wed. Jan. 26; I’ll put up a sample quiz on D2L this weekend

The fusion taking place in the Sun and other stars represents a tremendous energy source, and research has been directed at trying to promote controlled fusion reactions on Earth as a limitless source of energy (The world already has many fission reactors in which large radioactive elements such as uranium, decay and release energy)

Laws of Thermodynamics

First Law- Energy cannot be created or destroyed, but it can be converted from one form to another (examples of energy- heat, like, kinetic energy, electrical energy, potential energy of petroleum, food and gravity)

Second Law- No energy transformation is 100% efficient or Energy can be converted from one form to another but in all conversions there is formation of some ‘low quality’, ‘non-usable’ heat or Heat cannot be completely converted to work or Universe runs down as energy is dispersed to low-quality heat energy or All systems tend to become random (or dispersed) on their own (or all energy is not “equal”). Entropy is a measure of randomness, or dispersion or disorder

Origin of Solar System

There was about 10 billion years between the Big Bang and the origin of our Solar (Sun) system

Our solar system is made of all the elements of the Periodic Table but only He is being produced in our solar system currently (in the Sun); therefore all of the elements had to have been produced in the 10 billion years before the solar system was formed. (our system is from the remnants of other stars) Solar Nebula Hypothesis has solar system forming from a rotating ball of dust and gases that flattened to a disk shape. Most of the mass was in the center and the pressure and temperature in that environment ignited hydrogen “burning” (fusion).

Wed. Jan. 19

First Quiz next Wednesday (Jan. 26)

We need someone to provide their class notes for DRC students. Let Prof. Leavitt or Rebecca know of your interest, and we can devise a way of providing them.

We need 5 or 6 interested and responsible students to be group leaders (for 6 group activities), and receive 5 EC points. Let Prof. Leavitt know your interest.

We went over some answers to Homework #2 that had been handed out in class on Jan. 14. You will be quizzed on these skills in the first Quiz next Wed. Jan. 27.

Grand story of epic proportions:

ØOnly H and He (the most abundant elements in the Universe) were formed in the "Big Bang" 13-15 billion years ago; evidence of the Big Bang event is seen in the galaxies moving away from us at high speeds; the more distant the galaxy, the faster it is moving from away from us; Wavelengths are characteristic of electromagnetic radiation such as visible light (short wavelengths correspond to low pitch for sound waves, and red color for visible light waves; long wavelengths correspond to high pitch for sound waves, and purple color for visible light waves; see "electromagnetic radiation"); The “Red Shift” of visible light is associated with the “Doppler Effect” indicates galaxies are moving away from us at high speed to shift light toward longer wavelengths (red). Video of eye-popping, jaw-dropping, awesome reenactment of the Big Bang using a balloon with some marks on it, in full special effects mode with Dolby® Surround-sound®, and 3-D glasses, which illustrates how the galaxies farthest away could be moving at the greatest speeds.

ØElements from lithium (Li) to iron (Fe) (also He) produced in the interior of normal stars by “fusion” processes, i.e., lighter elements being combined to manufacture heavier elements. For example, in our Sun, fusion takes place converting 4 hydrogen atoms (1 proton in each nucleus = 4 nuclear particles) to one helium atom (2 protons and 2 neutrons in nucleus= 4 nuclear particles); the mass of the helium atom is less than the 4 hydrogens, so the difference in mass is what was converted to energy that contributes to the internal heat of the Sun (E=mc²); The energy from such nuclear reactions (involving nuclei of atoms) >> energy from chemical reactions (involving electrons of atoms); The fusion taking place in the Sun and other stars represents a tremendous energy source, and research has been directed at trying to promote controlled fusion reactions on Earth as a limitless source of energy (The world already has many fission reactors in which large radioactive elements such as uranium, decay and release energy)

ØElements up to Iron can be produced by fusion because energy is released; Elements beyond (heavier than) iron cannot be produced by fusion, but can be produced by high fluxes of neutrons that are captured in the nuclei of existing atoms; such neutron fluxes occur in interior of massive stars and when stars explode (supernova). Our sun has all of the elements of the Periodic Table, but it is only making He through fusion- Why?

Fri. Jan. 14

Syllabus handed out and key points reviewed; course web site is accessible through D2L containing many links for syllabus, website, homework, readings, skills, etc.

Daily readings from Mann/Kump (required) and Mackenzie (recommended) textbooks are listed in syllabus, but additional readings will be announced and made available through course web site;

You are responsible for knowing what is in the syllabus, particularly related to instructors contact information, policies, deadlines, grading, etc……at least 2 questions on first quiz will come from list of questions at end of syllabus.

Course content involves Earth’s systems, natural and human-induced mechanisms of global change, and nature of global changes.

Student can earn up to 6 Extra Credit points that will be added directly on to their final cumulative course grade (a number between 0 and 100%)!

Note: Office hours in room 330 Space Sciences are available immediately before (11-12 with TA Rebecca) and immediately after (1-2 with Prof. Leavitt) our class on Mon. and Wed.

Cheating/plagiarism is dangerous in this class- it can get you a recommendation for grade of “E” and referral to Dean

Don’t distract instructor or students with ringing cellphones, newspaper readings, sleeping, extended conversations, etc!

Attached to syllabus was also Homework 2 (atom size [diameter, mass], moles, speed of light, conversions, etc) containing problems for students to work and Periodic Table; Homework 2 will not be graded. If anything is not clear, Homework 1 has lots of explanation about scientific notation, graphs, conversions, etc (likewise, it is not to be turned in or graded). Both homeworks are available on the course homepage as well.

The AD 535global catastrophe was described based on the ‘Cerceo’ required reading, whose thesis is that some catastrophes we are helpless to prevent, but others (global warming related to use of fossil fuels) we can.

Class was also asked about main points from the ‘August’ opinion piece in the Tucson Weekly, in regard to “old ways”, sustainability, locavores, and flourishing or collapse of societies. No one knew what a locavore was, and all were asked to find out by the next class.

The fragility (uniqueness?) of blue Earth in the universe was portrayed with Earth viewed from Apollo and Voyager.

Characteristics of matter

All matter is made of small particles (atoms and their constituents)

Atoms of the same element have similar chemical properties

Atoms are not divided by chemical reactions

Chemical reactions involve electrons; nuclear reactions involve protons/neutrons

(in a column of period table different elements may behave similarly in chemical rxns)

Periodic Table

Elements arranged according to increasing Atomic Number (number of protons).

(This arrangement is also related to filling of electrons in discrete electron “shells”)

Each element has name and 1- or 2-letter shorthand notation.

When an atom is “neutral”, it will have an equal number of protons (+) in nucleus and

electrons (-) orbiting nucleus. Neutrons (no charge) also can reside in nucleus at the

center of atoms.

Intro to “grand story” of epic proportions regarding time, space, power, fire and ice, attraction and repulsion, collisions and explosions (sort of like Lord of the Rings, Star Wars, Bible, etc). The “Epic Story” told in the Periodic Table of Elements, which establishes a context of time and space in which our world exists

Wed. Jan. 12 (Wed.)

No class; University cancelled classes on Wednesday because of the tragic events of last Saturday, Jan. 8