EPS 7 Midterm 2 Review
what is the radiative forcing of the other positive forcings combined?
+1 W/m2
what is the radiative forcing of CO2?
+2 W/m2
how much will the average American use of fossil fuels each year?
- 3 tons of coal - 2400 cubic meters of gas - 22 barrels of oil
what were the preindustrial levels of carbon?
- atmosphere: 600 GtC - land/plants: 500 GtC - soils: 1500 GtC - ocean: 40,000 GtC
what are the underground concentration carbon?
- coal (5000 GtC) - gas (250 GtC) - oil (350 GtC)
what are the three fossil fuels?
- coal (C or CH) - oil (CH2) - gas (CH4)
what have we used of the underground concentration?
- coal: 200 GtC burned - oil: 150 GtC burned - gas: 50 GtC burned
why is global warming a positive forcing (aka net inflow increases)?
- higher CO2 causes a higher altitude of T =1 surface emitting to space - since atmosphere has lapse rate of 6.5 K/km, its colder higher up - by SB law, a colder T = 1 surface radiates away less power => holds in more radiation
what are things conserved?
- mass (kg) - momentum (kg x m/s) - energy (kg x m2/s2 or J)
what is the total feedback parameter given all the feedbacks?
-1 W/m2/K
middle clouds
-altostratus: middle layers -altocumulus: middle heaps
high clouds
-cirrus: hair like -cirrostratus: hair like layers -cirrocumulus: hair like heaps
clouds w/ vertical development
-nimbostratus: layer of precipitation -cumulonimbus: heap of precipitation
low clouds
-stratus: layer (you can't see the sun but theres no wetness from precipitation) -stratocumulus: layer of heaps -cumulus: regular ass cloud
who owns climate models in the US?
1) NASA 2) NOAA 3) NCAR 4) DOE
why is climate sensitivity defined in terms of doubling?
1) a doubling is convenient 2) each doubling gives roughly same amount of warming
what are the three things that can burn that contribute to positive feedback?
1) peat 2) permafrost 3) clathrates
how does the atmosphere interact with radiation?
1) scatters some shortwave 2) aborbs and emits longwave
what are the four signs of warming?
1) tropical glaciers 2) borehole temperature 3) surface-air thermometers 4) satellites
what is the current global emission of CO2?
10 GtC/year (5 into ocean, 5 into atmosphere)
methane in the atmosphere oxidizes to CO2 on what timescale?
10 years
what is the timescale of hiding carbon for the dissolution of CaCO3?
10,000 years (to hide 80% of burned carbon)
what is the timescale of hiding carbon from silicate weathering?
100,000 years (for the remainder)
in a business-as-usual scenario, what is a likely concentration of atmospheric CO2 in the year 2100?
1000 ppm
what is the timescale of carbon hiding by ocean acidification?
1000 years (to hide 60% of burned carbon)
what is the likely amount of carbon contained in methane clathrates?
1000-10000 GtC
ff we hold the concentrations of greenhouse gases constant at the levels anticipated in 2100 for the RCP8.5 scenario, roughly how much land warming would we get if we waited long enough?
12 K
when did the Big Bang occur?
14 Gya (billion years)
when was oil formed from the Jurassic?
150 Mya (million years)
in what year was the greenhouse effect postulated, thereby initiating the field of climate science?
1824
1 ppm
2 GtC
roughly at what rate is the atmospheric concentration of CO2 increasing?
2.5 ppm/year
the carbon contained in peat down to 1 meter is equivalent to how many years of fossil-fuel burning at the current rate of emissions?
20
how much carbon is there in peat worldwide down to one-meter depth?
200 GtC
where does the burning of fossil fuels go?
250 GtC to atmosphere, 150 GtC to ocean
what was the preindustrial concentration of carbon dioxide?
280 ppm
how much has Berkeley warmed?
2K
whats the radiative forcing for a doubling of CO2?
3 W/m2
when was Earth formed?
3.5 Gya (billion years)
how much is in one GtC (gigaton) of carbon?
3.7 Gt of CO2
when was coal formed from carboniferous?
300 Mya (million years)
when did fossil fuels from organism form?
300-500 Mya (million years)
If we hold the concentrations of greenhouse gases constant at the levels anticipated in 2100 for the RCP4.5 scenario, roughly how much globally averaged warming would we get if we waited long enough?
4 K
how much fossil fuel have humans burned?
400 GtC
what is the current concentration of atmospheric CO2?
400 ppm
If we hold the concentrations of greenhouse gases constant at the levels anticipated in 2100 for the RCP4.5 scenario, roughly how much land warming would we get if we waited long enough?
6 K
If we hold the concentrations of greenhouse gases constant at the levels anticipated in 2100 for the RCP8.5 scenario, roughly how much globally averaged warming would we get if we waited long enough?
8 K
if a sand dune's feedback parameter is −20 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of −4 m?
80 kg/s - because sudden height perturbation = final perturbation
given Earth's feedback parameter of -1 W/m2/K, what is roughly its final temperature perturbation in response to a brightening of the Sun that leads to 9 W/m2 of extra solar absorption?
9 K
what chemical formula most accurately describes the burning of natural gas?
CH4 + 2O2 → CO2 + 2H2O
when permafrost thaws, it releases
CO2 and CH4
which is not a contributing factor to the seasonal cycle in atmospheric CO2?
CO2 is a greenhouse gas
what happens in ocean acidification?
CO2 is added, reacting with H2O to make H2CO3 (carbonic acid) -H2CO3 will give up a H+ ion to make HCO3- (bicarbonate ion) - HCO3 gives up its H+ to created CO3-- (carbonate ion)
which compounds have positive forcings?
CO2, CH4, N2O, O3, halocarbons
what happens in dissolution of CaCO3?
CaCO3 dissolves and increases pH, allowing more carbon to dissolve
what chemical reaction ultimately removes the excess carbon from the atmosphere and ocean?
CaSiO3 + CO2 → CaCO3 + SiO2
which chemical reaction describes ocean acidification?
H2CO3 → H+ + HCO3−
which are greenhouse gases?
H2O, CO2, CH4 (opaque)
which are not greenhouse gases?
N2 and O2 (transparent)
aresols
NOT aersol, but a suspension of fire solid/liquid droplets in air - volcanic ash, pollen, sea salt, soot - decrease Earth's albedo, which decreases absorption of radiation
who first predicted global warming and made a calculation of Earth's climate sensitivity in 1896?
Syvante Arrhenius
how deep into a gas does the gas emit radiation like a solid surface?
T = 1
who was the IPCC founded by?
WMO and UNEP in 1988; first repot in 1990
what is methane clathrate?
a crystallized lattice structure of water with CH4 molecules trapped in between
advanced microwave sound unit (AMSU)
a fancy atenna that picks up microwaves from Earth's atenna - flys in a polar orbit -measures the T = 1 layer by k
how much coal have we used?
a few percent
how much warming do boreholes show?
about 1 K from preindustrial
which compounds have negative forcings?
aersols
stock
amount of stuff in container
lapse rate feedback
as Earth warms, the lapse rate changes, causing the T = 1 level to warm faster => increases longwave emission - there's a cooling effect - negative feedback
water vapor feedback
as earth warms, air holds more water vapor, decreasing longwave emission - causes more greenhouse gases - positive feedback
what is earth's climate senstivity?
averaging 3K, but can be 1.5-4.5K
what happens in silicate weathering?
basically weathers rocks to produce CaCO3 that gets flushed into oceans
why are clouds white?
because all wavelengths are scattered equally
why the is the Sun orange?
because light was not scattered (longwaves)
why is the sky blue?
because shortwave radiation is scattered (aka blue wavelengths)
why are we not worried about CO2 emissions from the ocean?
because the carbon dioxide in the ocean is dissolved
why is the Northern Hemisphere more important?
because there is more land, so the cycle of photosynthesis and respiration are more based on the northern hemisphere
halocarbons
carbon atom with atom from halogen element (Cl and Fl) - used as a refrigerant in air conditioning and used to be in hairspray - mainly stoped using bc it depletes ozone
CH4
caused by livestock burps, landfills, rice paddies, and fugitive natural gas (leaky) - causes more radiative forcing than CO2, but eventually becomes CO2
optical depth equation
change in T = kp X change in z
what does it depend on?
change in T= kp X change in z - k = constant (depends on the gas and wavelength of light) - p = density - z = distance
feedback parameter
change in net inflow per change in stock; tells us how much net infow changes for a given perturbation
what makes earth's climate sensitivity uncertain (predicted at 3 K but can really be 1.5-4.5 K)?
clouds
which of the following carbon pools has the largest amount of carbon at present?
coal
pH
concentration of H+ ions in a solution
ozone (O3)
created from NOx (NO and NO2) and VOCs (volatile organic compounds) - think smog
Joseph Fourier
created the heat equation; credited with postulating the existence of a greenhouse effect and thereby kicking off the field of climate science
John Tyndall
discovered greenhouse gases - found that there were gases that were transparent, but that others were opaque and could absorb and hold longwave radiation
when is warming the greatest?
during the initial warming, since warming amounts decrease with time
what is climate sensitivity aka?
equilibrium climate sensitivity, because we wait for Earth to equilibriate to a new CO2 level
what does respiration do with carbon?
expels it with water vapor
forcing
externally applied change in a flow, specifically net inflow - negative: external reduction - positive: external increase
perturbation
extra stuff (in excess of steady state flow); change in stock - can be positive (more) or negative (less) stock than usual
final perturbation
forcing/feedback parameter - only applies to negative feedback systems (aka only stable systems, so not sand dunes)
coal
fossilized peat (swamp soil) that is compressed to the point where it dries out, depleting it of oxygen and leaving carbon
oil
fossilized plankton that is compressed at high pressures and temps
conservation laws
fundamental principles that tell us that certain things are neither created nor destroyed; no exceptions!
Jules Charney
gave the first modern estimate of earth's climate senstivity
how much oil have we used?
half
how does ocean hide carbon?
hides it through bicarbonate ion (HCO3-), but that makes ocean more acidic bc of more H+
optically thick
if some amount of gas is opaque to radiation (aka does not allow passing)
optically thin
if some amount of gas is transparent to radiation (allows passing)
T = 1
in between transparent and opaque; right where gas goes thin to thick
is Earth in a steady state?
in preindustrial yes because the flow in of sun's energy equaled flow out of radiation, but right now NO
if the atmosphere does absorb/emit longwave radiation
infrared thermometer reports 200-300K - when it doesn't, it reports 3K
flows
inputs or outputs for a container of stuff
what does photosynthesis do with carbon?
intakes it to create oxygen and glucose
IPCC
intergovernmental panel on climate change
what makes Earth different from Mars and Mercury?
it has an atmosphere
if a sand dune's feedback parameter is +8 kg/s/m, what happens if we suddenly reduce the height of the dune by 2 m?
it will disappear
if a sand dune's feedback parameter is −5 kg/s/m, what happens if we suddenly add 4 m of sand?
it will go back to steady state bc we add stock
Planck's feedback
largest negative feedback system - more longwave emission that goes out has a cooling effect by SB law
with a negative feedback system, forcing
leads to a new steady state; reestablishes equilibrium - if the earth warms, it will cool - if the earth cools, it will warm
cloud feedback
less clouds has lower albedo, so more sunlight is absorbed and warms - positive feedback
ice feedback
less ice and snow causes lower albedo, which causes more sunlight to be absorbed - positive feedback
how do greenhouse gases work? what is the greenhouse effect?
lets shortwave in, but traps that energy by slowing longwave emission and collective cooling - basically traps longwave from escaping
longwave
little scattering, but a lot of absorption and emission
Charles David (Dave) Keeling
made scientists aware of global warming because of measurements at Mauna Koa in 1953
acid
molecule adding H+ ions to water
which of the following is a violation of conservation of mass/momentum/energy?
nothing
static equilibrium
nothing is happening
optical depth
opacity in T (tau)
T > 1
opaque (optically thick)
gas
overcooked oil
what is scotch made from?
peat
what do we call the layer of the Sun that emits light to space?
photosphere
what occurs more in the summer?
photosynthesis
infared thermometer
power per area in infrared radiation emitted by an object you point at it - calculates T by PPA
nitrous oxide (N2O)
primarily the result from fertilizers, but also used as a propellant and as laughing gas
Luke Howard
published paper in 1803 that we use to classify clouds today
what occurs more in the winter?
respiration
what do stevenson screen measurements show?
show an increase in surface air temps (and collectively across locations too) through min and max temps
what book is credited with kicking off the U.S. environmental movement in 1962?
silent spring by rachel carson
shortwave
some scattering, but very little absorption and emission
what do IPCC assessments do?
summarize the state of climate science
what happens with each doubling?
the amount of warning gets smaller, but still increases
climate sensitivity
the change in mean global temp for a doubling of atmospheric CO2
what motivated the formation of the International Meteorological Organization, later renamed the World Meteorological Organization, in the 1800s?
the desire for weather knowledge, large storms for Europe, and telegraph
why does burning fossil fuels cause global warming?
the extra atmospheric CO2 lifts the τ = 1 layer to a colder level in the atmosphere
the higher the k and/or ρ of some gas in the atmosphere...
the higher the effective height emission to space
how can we use borehole temps to show warming?
the more you descend in boreholes, the more sampling you get from thousands of years ago. upper layers are warmer than they should've been
global warming
the response of Earth's steady-state heat budget to a positive forcing from extra greenhouse gases in the atmosphere -decrease of radiation flow out (bc radiation is being held)
the higher the density (p)...
the shorter the distance change in Z to get to T =1 - today, the density of greenhouse gases is increasing, so we get to T =1 faster
feedback
the system's natural change in inflows in response to a perturbation; positive amplifies the perturbation, while negative dampens the perturbation
timescale
the time it takes something to get mostly done
what is the active layer?
the top layer of permafrost that thaws out
when there is a geometric increase in CO2
there is a linear increase in temp
what is happening to the glaciers?
they are disappearing
supercomputer
thousands and millions of computers wired together for parallel computing
steady state
total flow in = total flow out
T < 1
transparent (optically thin)
stevenson screen
used for surface air temp measurements; enclosure that shades and ventilates, as well as reflect away sunlight
what does AMSU show?
warming at low altitudes and cooling at high altitudes
what is the reality if we keep going?
we will more than double but less than quadruple our CO2 ppm
grid cells
weather and climate models discretize the world into boxes
serial computing
when a single computer solves a single problem
why is ocean acidification bad?
when acid increases, it blocks the production of CaCo3, which harms animals w CaCo3 structures (coral, sea butterfly, sea urchin)
parallel computing
when multiple computers solve a single problem
negative feedback
when there is a decrease in perturbation size; males steady state possible
positive feedback
when there is an increase in perturbation size
James Hansen
woke the public to global warming in 1988
