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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