EARTH RESOURCES, LOCKED IN.

what is the human population of the earth now

8 billion

approximately what is the 2019 UN medium projected population for the year 2100

10 billion (10.4 , to be precise)

doubling time for 3% growth rate

23 years “about 35” (ln[2]/rate of growth)

doubling time for factor of 10 increase

76 years “about 75”

how much of the oil that has ever been burned has been burned in prof.kelemen’s lifetime (64 years)

about 95%

if your children choose to continue current trends of oil extraction, and use more than 95% of all oil that has ever been used by 2090, how much more will you have to find, extract, and use by then

20x more

what is external cost

cost of producing a commodity born by “the public”

in acid rain, the pH is

lower than normal

emissions from burning coal, smelting copper, etc. that cause acid rain include

sulfur oxides and nitrogen oxides

what are the four main layers in the solid earth

(solid) inner core, (liquid) outer core, mantle, crust

what types of evidence are used to constrain the composition of earth

the composition of samples from the earth’s mantle, the composition of carbonaceous chondrites, and the composition of the earth’s crust

how was seafloor spreading discovered

marine magnetic measurements

is the earth expanding

no

if the earth (and continential crust) is more than 4 billion years old, where is the oceanic crust more than 180 million years old?

subducted

subduction zones are also called

convergent plate boundaries

mid-ocean ridges are also called

divergent plate boundaries

true or false: continental crust is more dense than oceanic crust

false

true or false : continental crust is more SiO2 rich than oceanic crust

true

true or false: continential crust has higher Mg, Fe, and Mg/(Mg+Fe) than oceanic crust

false

true or false: continential crust is thicker than oceanic crust

true

true or false: continental crust is felsic

true

characteristics of continental crust

less dense, thicker (hard to subduct), felsic, incomaptible elements (SiO2), older

characteristics of oceanic crust

thinner, denser, mafic, rich in compatible elements (Fe+Mg) — young, hot, and compatible

where is the youngest oceanic crust

C — symmetric about C

compared to felsic rocks, mafic rocks have

less SiO2 , higher Mg(Mg+Fe)

incompatible elements are concentrated in

evolving magma undergoing crystalisation

the most abundant elements in the contential crust (incompatible)

oxygen and silicon

where are compatible elements

mafic oceanic crust and mafic intrusions enriched in compatible elements

where are incompatible elements

felsic continental crust enriched in incompatible elements

highest T/P (temperature/pressure)

mid-ocean ridge

lowest T/P (temperature/pressure)

subduction zone

economically and legally recoverable oil in known deposits

reserve

all of the ultimately recoverable oil on earth

resource

compared to CH4 (methane) and other hydrocarbons, CO2 is

oxidised

coal is mainly formed by thermal maturation at depth of

reduced plant material

oil is mainly formed by thermal maturation at depth of

reduced microbial material

what is a spontaneous reaction

RELEASES energy (eg combustion aka oxidation)

what is a non-spontaneous energy

requires energy as an input, reduction (solar energy, photosynthesis)

oil is found ….

in shallow marine sediments that have been buried at 1-4km depth, younger than 400 million years, not extensively faulted or deformed

the amount of oil that can ever be recovered on earth is

the size of a resource

mars and venus have atmospheres with more than 95% CO2, as did the early earth, whereas at present earth’s atmosphere contains only 400ppm CO2 (0.04%). where is most of the missing carbon?

in sedimentary rocks

what does EROEI stand for

energy returned on (energy) invested

as production moves from conventional to unconventional sources of oil, EROI

decreases

according to the US energy infromation administration, electricity production via conventional combined cycle gas-fired generators is more expensive than via conventional coal-fired generators

true

the ratio of reserves (in tons) divided by production (in tons per year) has units of

time

the reserves of a finite , non-renewable resource that is being produced for consumption, always decrease with time

false (new discoveries + technological advancements + changes in price)

which country uses more coal than all other countries in the world combined

china !

rank the following in order of increasing energy density, in terms of joules per cubic meter - anthracite coal, lignite coal, oil, natural gas at atmospheric pressure

natural gas at atmospheric pressure, lignite coal, oil, anthracite coal

EROI for tar sands production is

lower than for conventional oil

EROI for US oil production on average is lower or higher than saudi arabian production

lower than for saudi arabian production

global oil consumption is

increasing

global oil reserves are

increasing

global oil formation via maturation of hydrocarbons is

slower than production

coal is more important than natural gas in US electric power generation

false

if the growth rate of shale gas production in the US remained at about 33% per year, approximately how long will it take for production to double (natural log 2 [0.7]/rate)

2 years

if the growth rate of shale gas production in the US remained at about 33% per year, approximately how long will it take for production to increase by a factor of 10 (natural log of 10 [2.3]/rate)

7 years

if electricity generation using wind increased exponentially, by a factor of 10 in 15 years, what is the annual rate of increase

years = 2.3 / rate

rate = 2.3 years

rate = 2.3/15 = 0.15 = 15%

actually, closer to 17%

in EIA estimates for 2017, 2018, 2019 and 2022, the costs of electric generation in the US using conventional coal-fired power plants has been

higher than for conventional gas-fired power plants

coal is more important than natural gas in global electricity generation

true

gas hydrates are found in areas with

more than a few 100m of water depth with bottom water temperatures less than 10 C (100-10,000m below seafloor)

in terms of stored energy, gas hydrate resources may exceed all other hydrocarbon resources

true

over the past several decades, global energy consumption has been growing at about

1.5-4% per year

over the past several decades, the doubling time for global energy consumption has been

23-35 years

over the past century, the time to increase global energy consumption by a factor of 10 has been

76-115 years

the most abundant greenhouse gas in the atmosphere

H2O

the frequency of the approximately 100,000 year cyclicity in global mean temperature is thought to be set by

variations in the earth’s orbit around the sun

amplifiers that increase the temperature and CO2 response to changes in the earth’s orbit and rotation axis include

CO2 solubility in seawater decreases with increasing temperature + continental glaciation and polar ice caps reflect more incoming solar radiation back into space compared to rock, soil, and open water

true or false: greenhouse gases like CO2, CH4, NO2, H2O are nearly transparent to short wave, visible light and absorb long wave, infrared radiation

true

as seawater temperature decreases, the solubility of CO2

increases

the temperature of deep ocean water is

colder than at the surface

H2O is a greenhouse gas

true

how do we know about the medieval warm period?

it is indicated by data from tree rings and the shells of marine micro-organisms

the pH of the ocean goes up with increasing CO2 content in the atmosphere

false, it becomes more acidic, so the pH decreases

how many tons of C is 3700 Gt CO2 (3700 billion tons CO2)

about 1 trillion tons

the IPCC and others have identified the total cumulative emissions of carbon (and other greenhouse gases in equivalent units) that can be emitted, since 1850, without causing the earth to warm more than 2 C on average. this value is

around 1,000 billion tons (1 trillion tons) of carbon

at the current rate of increase of greenhouse gas emissions, this cumulative amount will be exceeded

in less than 75 years

estimating the “social cost of carbon” is affected by

• the uncertinaity in the magnitude and distribution of weather changes for a given increase in temperature

• the uncertainty in the magnitude of temperature change for a given increase in atmospheric CO2 and other greenhouse gases

• the uncertainty in the nature, magnitude, and spatial distribution of economic damage resulting from a given increase in temperature, change in climate, and/or change in ocean pH

most renewable electricity production is via hydroelectric generation

true

solar energy reaching the earth’s surface is orders of magnitude larger than human energy consumption

true

is using a turbine to spin a magnet inside a coil of wire a generator or an electrical engine?

• a generator converts mechanical into electrical, while an electrical engine converts electrical into mechanical

• thus, this is a generator

is using a current in a coil of wire to spin a magnet a generator or an electrical engine?

• a generator converts mechanical energy into electrical, while an electrical engine converts electrical into mechanical

• thus, this is an electrical engine

true or false: compressed CO2 is denser than water at temperatures below 10 C and ocean depths greater than 4 km

true, and this is significant because of the potential to store CO2 in “ponds” on the seafloor

storage options to smooth out intermittent wind and solar power generation include

batteries, huge steel fly wheels, pumping water uphill, splitting water into H2 and O2 , molten salt, compressed air in caves

in the periodic table excerpt above, in the rectangle for uranium, what is the number 92

the atomic number , which is equally the number of protons

in the periodic table excerpt above, in the rectanglel for uranium, what is the number 238.03

atomic weight , which is also the average number of protons + neutrons

how many neutrons are there in 238 U (atomic weight = 92)

atomic number = 92 = number of protons

atomic weight = 238 = number of protons + neutrons

neutrons = 238 - 92

total number of neutrons = 146

which naturally occuring isotope of uranium is most abundant

238 U

which naturally occuring isotope of uranium is enriched for reactors and bombs

235 U

to avoid 1 billion tons of carbon emissions due to generation of electrical power using fossil fuels, 50 years from now, nuclear energy generation capacity would have to

increase by a factor of three

if current trends continue, will nuclear energy generation capacity increase by the amount required in the previous question (by a factor of three)

no

true or false: over the past 50 years, cumulative deaths due to accidents at nuclear power plants and to exposure to waste from nuclear power plants have been greater than deaths due to coal mining

false

true or false: a nuclear chain reaction results from the fact that, for example, each U 235 fission, triggered by capture of one neutron, produces three neutrons which can be captured by three more 235 U nucleii

true

true or false: control rods absorb neutrons to slow a chain reaction while moderators slow neutrons to increase the likelihood of neutron capture by a 235 U nucleus to ensure a chain reaction

true

what elements are used as control rods in nuclear reactions

Ag, In, Cd, Boron, Hafnium

what elements are used as moderators in nuclear reactions

H2O, D2O, graphite

how many years does it take for radioactivity from nuclear waste (spent fuel rods) from a typical US nuclear power plant is reduced to the level of a moderately safe uranium mine

one million years

true or false : breeder reacotrs actually can be said to perform “alchemy” , transforming one element into another, and consuming weakly radioactive elements to form new, highly radioactive isotopes (eg, making several isotopes of plutonium from 238 U, making 233 U from 232 Th)

true

if widely adopted, breeder reactor technology would greatly increase the avaliable resource for nuclear energy generation

true

why is breeder reactor technolgoy not widely used in the US and many other countries

• newly formed elements are chemically separable from their parent elements, and thus it is far easier to create bomb-grade material from breeder reactor products than to separate 235 U from 238 U

what is fusion

merging of two isotopes, most likely isotopes of hydrogen, to form a heavier isotope, typically helium