unit 8, exam 2 Flashcards
faint young sun paradox
sun gets stronger with time so early Earth received about 70% of current energy, but Earth was still hot
sunspot cycles
11 years
more sunspots=more energy output. not enough to drive climate change
milankovitch cycles and orbital parameters
eccentricity
precession
obliquity
eccentricity
100,000 year cycle
changes in how extreme the elliptical orbit is. how close or far away the earth is from the sun
perihelion
point closest to the sun
right now in january
aphelion
point furthest from the sun
right now in june
precession
23,000 year cycle
changes that effect which hemisphere faces the sun during the perihelion/aphelion
-changes the contrast between summer and winter seasons
-THIS IS WHY ICE AGES ARE POSSIBLE
colder summers are what can make ice and snow and glaciers expand
obliquity
41,000 years
earths axis tilt changes from 22.1-24.5 and back over those years.
as tilt increases=winters colder, summers warmer
tilt decreases=seasons even out
global contributions
plate techtonics
volcanoes
plate techtonics
determine land mass and how radiation is absorbed by earth
10million to 100 million years
volcanoes
1-millions of year time scale
increase in greenhouse gases
some decrease because of aerosals(mt.pinatubo) (aerosal dimming)(deccan traps)
future trend of milankovitch cycles
less elliptial orbit
closer to the sun in june
lesser axis tilt
ALL POINTING OPPOSITE OF CLIMATE CHANGE
aerosal dimming
absorb energy and scatter or send it back out as shortwave radiation
deccan traps
big plateau of volcanic stuff in india. potentially the demise of the dinos. huge eruption after astroid
positive feedback
climate change increases as a reaction to initial change. more of this in nature ice albedo feedback soil moisture feedback warm earth feedback
negative feedback
reaction to initial change tries to balance things back out
warm earth-evaporation feedback
arctic amplification
more heating is going on at the poles as compared to the equator
sinks
components responsible for removing carbon from another component
source
component responsible for adding carbon to another component
methane hydrate
melting of land with methane forms thermokarst lakes which decay and release methane into atmosphere increase in GHG then warms system and melts permafrost
human contributions of sources and sinks
Energy industry(GHG) Aerosols (global dimming & cooling effect) Land use/land change Agriculture
callendar effect
theory that global climate change can be brought about by enhancement of the earth greenhouse effect by increasing GHG concentration in the atmosphere
keeling curve
daily record of observations of CO2 at manua loa used as evidence that atmopheric CO2 is rising and contributing to climate change.
- 40% greater than industrial revolution
- burning fossil fuels accounts for 75% of deforestation
natural aerosals
volcanoes, dust, sea spray(salt), pollen, fire smoke
