EPS 7 Midterm II
National Environmental Policy Act (NEPA) 1969
A 1969 U.S. federal act that mandates an environmental assessment of all projects involving federal money or federal permits.
Optical Depth (colors/wavelength)
A gas can be optically thick with respect to one wavelength (e.g. blue) while it is optically thin with respect to another (e.g. red)
Optical Depth (scattering and absorption)
A gas can be optically thick with respect to scattering, but optically thin with respect to absorption. Or vice versa. (scatters before it has a chance to absorb) (absorbs before it has a chance to scatter).
DDT
A powerful insecticide that is also poisonous to humans and animals; bioaccumulated and killed eggshells of raptor birds--eagles, peregrine falcons
How much of the burned carbon can be hidden as bicarbonate in the ocean from equilibration of the atmosphere and ocean?
About 60% On what timescale? 1,000 years Why is the timescale so long? The ocean is big. 1,000 years is roughly how long it takes the ocean's circulation to expose all of its water to the atmosphere
How much of the burned carbon is hidden as bicarbonate in the ocean after calcium-carbonate dissolution?
About 80% On what timescale? 10,000 years
1 ppm = 2 GtC
Adding 250 GtC to atmosphere brings from 280 ppm to 400 ppm
Negitive Forcings (atmosphere)
Aerosols -1w/m^2
What is the primary source of anthropogenic nitrous oxide?
Agriculture
Any evidence that silicate weathering created CaCO3 in the past?
All of the remaining carbon put into the atmosphere by humans is removed by silicate weathering On what timescale? 100,000 years
How much carbon has gone into the atmosphere and ocean
Atmosphere: originally 600 GtC, now 850 GtC (+250 GtC) Ocean: originally 40,000 GtC, now 40,150 GtC (+150 GtC)
Rachel Carson/Silent Spring (1962)
Book published that chronicles Rachel Carson's concerns about pesticides and environmental contamination--SPARKED ENVIRONMENTAL MOVEMENT
Coal
C or CH; comes from carboniferous (300 mya); fossilized peat
Which of these is an example of a halocarbon?
CF2Cl2
Oil
CH2; comes from jurassic (150 mya); fossilized plankton; formed in the tethys sea
What chemical formula most accurately describes the burning of natural gas?
CH4 + 2O2 → CO2 + 2H2O
gas
CH4; gas is overcooked oil
Amount of ocean carbon in different forms
CO2 + H2CO3, HCO3-, CO3--
Photosynthesis equation
CO2 + H2O + photon → O2 + CH2O
carbonate chemistry
CO2 + H2O ← → H2CO3 ← → H+ + HCO3- ← → 2H+ + CO3--
When permafrost thaws, it releases
CO2 and CH4
Positive Forcings (atmosphere)
CO2: +2w/m^2 Methane (CH4) + Nitrous Oxide (N20) + Ozone (O3) + Halocarbons = +1w/m^2
carbonate ion
CO3--
Calcium carbonate
CaCO3 sea shell, chalk, marble, snail shell, limestone, egg shell; Ocean acidification is a big deal for calcium carbonate (CaCO3); The more acidic the ocean, the more difficult it is for these species (and many others) to make their calcium-carbonate structures - coral, sea butterfly, sea urchin
After 1,000 years, what happens to the remaining 40% of burned carbon that is still in the atmosphere?
Calcium carbonate (CaCO3) dissolves from the ocean floor and on land, raising the pH, and allowing more CO2 to dissolve into the ocean. It does this by the carbonate grabbing an H+ ion. CaCO3 → Ca++ + CO3-- Ca++ + CO3-- + H+ → Ca++ + HCO3-
the world has used so far
Coal: 200 GtC Oil: 150 GtC Gas: 50 GtC Total of: 400 GtC
Originally there was
Coal: 5,000 GtC Oil: 350 GtC Gas: 250 GtC Land plants: 500 GtC Soils: 1,500 GtC Ocean: 40,000 GtC Atmosphere: 600 GtC
IPCC (Intergovernmental Panel on Climate Change) 1988
Created by WMO and UNEP
World Meteorological Organization (WMO)
First established in 1873, renamed in 1950 and becomes part of the UN--an organization is established to exchange weather data between countries
Four U.S. climate models
GISS (NASA) GFDL (NOAA) CESM (NSF) ACME (DOE)
Jules Charney
Gave first modern estimate of ECS; 1979 Charney report estimated 3 C increase.
hydrogen ion
H+
carbonic acid
H2CO3
Carbon cycle
H2O--> CH2O (plant matter)-->(photosynthesis)O2 -->(respiration) CO2
bicarbonate ion
HCO3- Bicarbonate is an electrically charged ion, so it cannot leave Carbon in the form of bicarbonate is hidden from the atmosphere
John Tyndall
Identified gases responsible for greenhouse effect: -N2, 02, Ar are transparent to infared -H20 (water vapor), CO2, CH4 are greenhouse gases Discovered T=1 at 5km
What is an acid?
It is a molecule that can give up an H+ ion
Things that are conserved
Mass: with units of kg Momentum: mass x velocity, with units of kg x m/s Energy: various forms, with units of kg x m^2/s^2 (=Joule)
Rayleigh scattering
Molecules redirect photons into a new direction. Short wavelengths (blue) are much more easily scattered than long wavelengths (red, infared): why the sky is blue
Ocean acidification in a nutshell
More CO2 in the air → more CO2 in the ocean → more carbonic acid → more acidic ocean
amount of ocean carbon in different forms
Most: HCO3- (bicorbante ion) Middle: CO3-- (carbonate ion) Least: CO2 + H2CO3
Why would the earth breathe with an annual cycle?
Much more land in northern hemisphere NH Summer: Plants grow-->photosynthesis > respiration-->CO2 is removed SH Winter: Plants do not grow--> respiration > photosynthesis--> CO2 is added
Which of these is an example of a NOx?
NO2
Respiration equation
O2 + CH2O → CO2 + H2O + photon
CO2 is removed from the atmosphere by three processes
Ocean acidification - 1,000 years Dissolution of CaCO3 - 10,000 years Silicate weathering - 100,000 years
RCP 6.0
Paris agreement
Stuff that can burn
Peat, Permafrost, Clatherates
Joseph Fourier
Postulated the greenhouse effect (1824); surface receives twice as much radiation from the atmosphere than from the sun--enhancement of solar radiation., START OF CLIMATE SCIENCE
RCPs (Representative Concentration Pathways)
RCP 2.6w/m^2, 4.5w/m^2, 6.0w/m^2, 8.5w/m^2; IPCC make plausible scenarios for the future of emissions (not predictions)
After 10,000 years, what happens to the remaining 20% of burned carbon that is still in the atmosphere?
Silicate rocks (CaSiO3) chemically weather in the presence of CO2 and make calcium carbonate (CaCO3) which locks up the C in new limestone CaSiO3 + CO2 → Ca++ + CO3-- + SiO2 → CaCO3 + SiO2 Land rocks exposed to rainwater with dissolved CO2 Ions carried to the ocean in rivers Carbon locked away as new calcium carbonate on the ocean floor
In between trasnparent and opaque
T"="1
Transparent
T<<1
When does a gas emit to space
T=1; at each increment in T (tau) the gas behaves like the surface of a solid body
Opaque
T>>1
What does pH measure?
The concentration of H+ ions in the water, Lower pH is more H+
Bicarbonate is an electrically charged ion, so it cannot leave Carbon in the form of bicarbonate is hidden from the atmosphere
The ocean hides away most of the carbon that dissolves into it
climate sensitivity
The response of the climate system to a given radiative forcing
Parallel Computing
The simultaneous execution of the same task on multiple processors to obtain results faster.
What is acidic water?
Water with a lot of H+ ions in it
grid cells
Weather and climate models discretize the world into boxes
Higher Optical depth
You can get a higher optical depth between two locations by increasing the distance Or by increasing the density (e.g., by increasing the amount of greenhouse gases for longwave absorption and emission)
Global warming is caused by
a decrease in outgowing power, not an increase in incoming power --> positive forcing
Planck feedback (negative)
a negative feedback loop when the planet is warmer: --> more T^4 longwave emission --> cooling tendency
middle clouds
altostratus, altocumulus
Advanced Microwave Sounding Unit (AMSU)
antenna that picks up microwave signals emitted by earth's atmosphere; polar-orbiting satellite.Sun-synchronous: ascend and descend . over the equator at the same time each day and night.
Each increment in Tau
at each increment (T=1, T=2, T=3, T=4) the gas behaves like the surface of a solid body
Gya
billion years ago
RCP 8.5
business as usual
Doubling of CO2
causes 3k increase in global temp.
feedback parameter
change in net inflow per change in stock
Climate sensitivity is the
change in temperature for a doubling of CO2
High clouds
cirrus, cirrostratus, cirrocumulus
Total feedback in uncertain because
cloud feedback is uncertain--why ECS could be from 1.5 k to 4.5 k
Mie Scattering
clouds scatter light; cloud drops are bigger than N2 molecules--no wavelength preference; clouds are white.
Three types of fossil fuels
coal (C or CH), oil (CH2), natural gas (CH4)
FIngerprint of a CO2-induced global warming
cooling in stratoshpere, warming in lower atmosphere/surface (10km)
negative forcing
decrease stock; decrease spigot flow
Svante Arrhenius (1896)
determined that humans could create greenhouse effect by burning fossil fuels (1896)
Feedback
extra flow out (in excess of steady-state flow) response of flows to the perturbation
perturbation
extra water in tank (in excess of steady-state stock) Current stock - stock in original steady state
Conservation laws
fundamental principles of physics that tell us that certain things are neither created nor destroyed.
James Hansen (1988)
gave congressional testimony about global warming in 1988
Cirrus
hair
cumulus
heap
positive forcing
increase stock; increase spigot flow
ΔT=kpΔz
k=some constant (depends on gas and wavelength or light; big k for greenhouse gases and longwave) p=Density of the gas p Δz=distance
stratus
layer
The first forecasts
made by the Smithsonian in D.C. in 1857
supercomputer
made up of individual computers no more special than your laptop. A supercomputer is "super" because it is made of thousands or millions of computers wired together for parallel computing.
Dave keeling (1960s)
measurements of CO2 at Mauna Loa; first unambiguous evidence of rising CO2
alto
middle
Mya
million years ago
An extra molecule of CH4 in the atmosphere causes an extra molecule of CO2 in the atmosphere
more warming than
lapse rate feedback (negative)
negative feedback when the planet is warmer: --> lapse rate descreases -->T=1 emission layer warms faster than surface --> T=1 layer emits even more longwave --> cooling tendency
Vertical Clouds
nimbostratus, cumulonimbus
Peat
of the 1500 GtC in soil, peat accounts for 200 GtC; peat is made in swamps
nimbo
percipitation
WHat is the layer of the sun that emits light
photosphere
In summer
photosynthesis > respiration
water vapor feedback (positive)
positive feedback when the planet is warmer: --> air holds more water vapor (clausius-clapeyron) --> more greenhouse gas (water vapor) --> warming tendency
cloud feedback (positive)
positive feedback when the planet is warmer: --> fewer clouds -->lower albedo --> more sunlight absorbed -->warming tendency
Ice feedback (positive)
positive feedback when the planet is warmer: -->less ice and snow -->lower albedo -->more sunlight absorbed -->warming tendency
borehole temperatures
prove an increase of about 1K from preindutrial temperatures. Prof. Lonnie thompson from tOSU works on this.
Doubling CO2 (w/m^2)
radiative forcing of 3w/m^2
in winter
respiration > photosynthesis
Shortwave (in the atmosphere)
some scattering, but very little absorption and emission
surface-air thermometers
stevenson screen is an enclosed thermnometer that shades and ventilates; designed by thomas stevenson in 1864.
low clouds
stratus, stratocumulus, cumulus
positive feedback
tends to increase size of perturbation make the rich richer and the poor poorer (e.g. interest in a bank account)
nagative feedback
tends to reduce size of perturbation make the rich poorer and the poor richer (e.g. psychology)
Kya
thousand years ago
timescale
time for something to get mostly done
Evidence of warming
tropical glaciers, borehole temperatures, surface-air thermometers, satellites
Longwave (in the atmosphere)
very little scattering, but a lot of absorption and emission
Equlibrium climate sensitivity (ECS)
we wait until earth equilibrates (~100 years) to new CO2 level before differencing the mean temps. 1.5 C-4.5 C 3k
Which way do storms move in the continental United States?
west to east
RCP 2.6
wildly optimistic
Buys Ballot
(1872) Proposes an international network of stations in Europe
Final Perturbation = Forcing / |feedback parameter|
(only for negative feedback parameters!)
Total atmospheric forcing
+2w/m^2
Total feedback parameter
-1w/m^2/K
Serial computing
1 core processor completes one task before computing another. One cycle at a time
clathrate--methane clathrate
1,000-10,000 GtC; a compound in which molecules of methane are physically trapped within the crystal structure of water. As planet warms, clathrates release methane.
Land Warming
1.5x that of projected global mean warming
Current global emissions of CO2
10 GtC/ year; emissions double every 23 years; americans emit 4x as much CO2 than global avg; CO2 is rising 2ppm/year; pop. will rise to 11 billion in 2100
how much does atmospheric CO2 increase each year?
10 GtC: 5 GtC to atmosphere (+2.5 ppm), 5 GtC to ocean
Methane in the atmosphere oxidizes to CO2 on what timescale?
10 years
big bang; earth formed
14 gya; 4.5 gya
Clean Air Act 1970
1970 -- nixon
Environmental protection agency 1970
1970 -- nixon
United Nation Environmental Programme (UNEP) 1972
1972
Clean Water Act 1972
1972 --veto overridden
Endangered Species Act 1973
1973--nixon
first assessmnet report of IPCC
1990 working group I: Physical science working group II: Adaptation working group III: mitigation
IPCC released 5 assessment reports
1990, 1995, 2001, 2007, 2014; summarize state of science--do not generate new science-- 4000 pages with ~800 authors
Atmosphereic temp.
200K-300K
preindustrial CO2 concentration
280 ppm; first 280 ppm + 3k, 2nd + 1.8k, 3rd + 1.2k
How much has berkeley's temp increased?
2k; 3-4 F
What is the current radiative forcing from the extra CO2 that is currently in the atmosphere?
2w/m^2
With RCP w/m^2
2w/m^2 = ~ 1 K of warming at 2100, but will equal the same if we wait enough
How much does a person use of coal, oil, and gas?
3 tons of coal, 22 barrels of oil, and 2400 m^3 of natural gas)
Permafrost
350 GtC of 1500 GtC in soil permanently frozen layer of soil beneath the surface of the ground; topped by an active layer that freezes and thaws every year.Permfrost decays and emits CO2. Over all depths permafrost contains 1500 GtC
Space Temp.
3K
Earth's climate sensitivity
3K because: doubling of CO2 causes +3w/m^2and e a r t h' s feedback parameter is -1w/m^2/K final perturbation = forcing/|feedback parameter| =(3w/m^2)/|-1w/m^2/K| =3K!
Where is T=1
5 km in atmosphere
