Climate Change: From Puzzles to Policy

factors for planet surface temperature

distance from sun

atmospheric composition

reason for seasonal patterns + explanation for difference based on position vis-a-vis equator

tilted axis changes exposure to sun and radiation concentration throughout elliptical rotation

axis position compared to sun causes different levels of radiation for geographical global north vs. global south

important things to note about earth’s monthly average temperature over the years

seasonal cycles have remained the same

all months have been experiencing increased temperatures

main factor for climate

geography

which zone experience the most solar radiation and why

the equator, because the earth is not a perfect sphere, but rather an oblate spheroid

name the components of our climate system

atmosphere

ice

ocean

land surface

vegetation

explain how changes occur within the climate system

external forcings cause internal interactions between and with different components of the system

this leads to internal responses (ie: changes in the components)

name the potential external forcings and explain them

changes in plate tectonics (configuration of the continents impacts exposure to solar radiation)

changes in the earth’s orbit (changes in our tilt or orbital radius would also affect exposure to solar radiation)

changes in the sun’s strength (as a star, the sun decays, meaning it also transfers less of its energy to our planet)

what is temperature and how does it work

measure of internal heat energy —> measure of internal kinetic energy

the more energy, the faster molecules that make up a material are moving

types of energy transfer

conduction

radiation

convection

conduction

transfer of energy via physical contact

radiation

transfer of energy via electromagnetic waves

convection

transfer of energy via a third-party substance

explain depth of convection

dry convection is when the hotter materials rise less, moist is more

dry convection

no clouds

less than 1km

shallow convection

1st type of moist

cumulus clouds

1-3km

deep convection

2nd type of moist

cumulonimbus clouds

5-12km

sensible vs. latent heat

sensible means that transfer of heat is measurable (temperature change)

latent means heat is transfering in a way we cannot measure (no temperature change)

climate vs. weather

weather is short-time evolution

climate is long-term weather statistics

climate change

long-term change in climate-defining weather characteristics

fossil fuels and where they come from

comes from remains of ancient plants and animals

coal (found in sedementary rocks)

oil (heated up solid mixture of mud and clay)

natural gas (found in pockets above oil deposits)

zones of the atmosphere

troposphere (less than 10km)

stratosphere (10-50km)

mesosphere (50-85km)

thermosphere (85-120km)

pressure pattern as you go up through the atmosphere

decreased pressure due to lower amount of gas particles

gases go down due to gravity

describe heat patterns for the different zones

goes down as you move up through troposphere (less surface radiation)

goes up in stratosphere due to ozone absorption

very cold in mesosphere

technically lot of solar radiation in thermosphere but cannot be felt due to lack of radiation

why is the troposphere highest at the equator

because the equator is hotter, the gases get more heated up and rise higher

name the convection cells

hadley cells (less than 30 degrees)

ferrel cells (30-60)

polar cells (more than 60)

rules for coriolis force

Northern hemisphere deflects objects to the right, southern to the left

force is zero at the equator and increases with latitude

the force increases with an object’s speed

only change in direction, not speed

primary winds in the united states

easterlies (west to east)

ITCZ

intertropical convection zone (visible rising branch of the hadley cell)

cause for seasonal patterns in keel curve

plants grow during the summer → co2 uptake → less co2 in the atmosphere → decrease in curve

plants die during the winter → co2 outgasing → more co2 in the atmosphere → increase in curve

the hemispheres should cancel one another out, but the nothern hemisphere has a greater land mass, which leads to the curve showing its seasonal pattern

equation for pressure

force divided by area

biosphere

thin surface

supporting global ecosystem

components of ecosystem

living organisms

abiotic factors

biome

area within biosphere

photosynthesis and respiration

intake of co2 → creation of organic molecules → generation of energy → outgassing of co2

what absorbs co2 in ocean

phytoplankton

oceans

arctic

atlantic

pacific

indian

southern

structure of ocean

surface

epipelagic (sunlit) - 200m

mesopelagic (twilight) - 1000m

bathypelagic (midnight) - 4000m

abyss + trenches

causes for surface circulation

winds, tides, temperature, salinity

gyres

permanent current patterns

eddies

circular swirls

thermocline

temperature rapidly decreases

halocline

salinity rapidly increases

pynocline

density rapidly increases

cause for deep ocean convection

thermohaline

gases in atmosphere

mostly nitrogen

some oxygen and co2

small amount of other gases (argon)

main sources of human carbon emissions

fossil fuel burning

land use change

major types of land use change

commodity-driven deforestation

shifting agriculture

wildfire

forestry

physical and biologicak ocean pumps

solubility

photosynthesis and sedimentation

describe co2 placement

half in atmosphere

fourth in ocean

fourth in land

cause for accumulation of co2

sources being greater than sinks

types of radiation, lowest to highest energy

radio

microwave

infrared

visible

ultraviolet

x ray

gamma ray

rules of object wavelength range

hotter objects have shorter peak emission wavelength

total energy strongly depends on temperature

strongly in mathematical terms

to the power of 4

how do gases interact with radiation

solar radiation gets mostly either scattered or transmitted through

longwave infrared radiation gets absorbed and re-emitted

positive and negative feedback

positive enhances

negative counteracts

principal climate feedbacks

water vapor (higher concetration at higher temperature + traps heat)

surface albedo (melting of ice)

clouds (low clouds cool surface, heat is too high for cloud formation)

hot period and cold period

cretaceous and pre-cambrian (sturtian climate)

glacial morraines

accumulations of rocks, gravel, and sand carried by glaciers or ice sheets

change in ocean isotope ration

as ice volume goes up, heavier isotopes more common in ocean