Global Changes Exam 1

change in 1.0C

equals change in 1.8F

short wavelengths

high frequency

long wavelengths

low frequency

Percent IR energy which reaches the Earths surface

50%

Percent visible energy which reaches the Earth’s surface

40%

Percent UV energy which reaches the Earth’s surface

10%

Flux

the amount of energy in an electromagnetic wave that passes perpendicularly through a unit surface area per unit time

Stefan-Boltzmann Law

The amount of energy radiated is proportional to the temperature of the object raised to the fourth power

Wien’s Law

The hotter the object, the shorter the wavelength of the emitted energy

Inverse Square Law

When distance from an energy source doubles, the intensity decreases by a factor of 1/4

Earth’s current albedo

0.3

Temperature of the Earth without greenhouse gases

-18C 

Observed temperature of Earth with greenhouse gases

15C

Units out of 100 solar radiation reflected by atmosphere

30

Units out of 100 of solar radiation absorbed by atmosphere

25

Units out of 100 solar radiation absorbed by Earth

45

Total units out of 100 emitted back to space by Earth

70

Negative feedback loop

Stable system which resists change following a perturbation

Positive feedback loop

Unstable system which changes further following a perturbation

Forcing

Persistent disturbance of a system

Perturbation

Temporary disturbance of a system

Time delays

Cause negative feedback loops to take too long and a tipping point is reached

Unstable Equilibrium State

Shifts to a new stable state when pushed by a perturbation

Stable equilibrium state

Returns to the original state when pushed by a perturbation

CO2, CH4, H2O

Greenhouse gases abundant on early Earth

Volcanoes

Supplied CO2 to early Earth

Produced by volcanoes and biological processes

CH4 on the early Earth

H2O

Greenhouse gas which is self regulating

The uplift of the Himalayas

Triggered the Cenozoic cooling period by exposing rock which consumed atmospheric CO2 when weathered

Carbonate Silicate cycle

Moves atmospheric CO2 by subducting precipitated carbonates in the ocean over 100-200 million years