Chapter 6 Flashcards
What happens to energy out as the planet heats up?
energy out increases
What do warmer objects radiate more of?
blackbody energy
What is radiative forcing?
Factors that are not initiated by the Earth’s surface temperature, but create warming or cooling (climate change)
affects climate (temperature), but is unaffected by climate (temperature)
What would the radiative forcing in W/m^2 be if CO2 in the atmosphere doubled?
+4 W/m^2
What are aerosols?
particles so small they don’t fall under the force of gravity but remain suspended in the atmosphere for days/weeks
What are sulfate aerosols?
sulfur gases react with other atmospheric constituents to form small liquid droplets
exists in lower atmosphere
What are black carbon aerosols?
produced by incomplete combustion
absorb solar radiation and decrease planet’s albedo, warming the planet
What is mineral dust?
natural process, dust picked up by wind
What is the aerosol direct effect?
scattering or absorption of solar radiation by aerosols in the atmosphere
How do aerosols alter clouds?
they increase the number of particles in a cloud
What is cloud-condensation nuclei?
small hydrophilic aerosols
attract water
What is the aerosol indirect effect?
impact of aerosols on clouds
What is climate sensitivity?
predicted increase in Earth’s average surface temperature
What are feedbacks?
processes that respond to changes in the surface temp
What is the difference between radiative forcing and feedbacks?
feedbacks do not initiate climate change whereas radiative forcing does
What is positive feedback?
output regulates process to increase(increases temp)
What is negative feedback?
output regulates processes to reduce/reverse(decreases temp)
What is ice-albedo feedback?
positive feedback loop that occurs when a decrease in snow and ice leads to more solar radiation
What is water vapor feedback?
arises because a warmer atmosphere can hold more water vapor
What is lapse-rate feedback?
biggest negative feedback
occurs when troposphere warms unevenly, changing how much atmosphere cools
What is cloud feedback?
reflect sunlight back to space
absorb infrared radiation by surface
What is the runaway greenhouse effect?
initial temperature change leads to large temperature rise
What are slow feedbacks?
processes that respond slowly increasing surface temperature
What is the carbon-cycle feedback?
initial warming leads to release of large amounts of CO2 and methane currently frozen in the ground
What do positive and negatives mean in forcings?
+ means temp is increasing
- means temp is decreasing
relative to Industrial Revolution
What does ice-albedo feedback do to albedo?
decreases it
What kind of feedback loop is water vapor?
positive
How long does water vapor feedback take?
fast
What does the cloud #1 feedback loop look like?
inc temp –>more clouds–>more water vapor=more clouds–>increase in albedo (lowers radiation)
negative feedback loops
takes weeks
What does the cloud #2 feedback loop look like?
inc temp–>more clouds–>more water vapor=more clouds–>absorbs infrared radiation–>increases greenhouse gases
positive feedback loops
takes weeks
What kind of feedback loop is permafrost and how long does it take?
positive
decades
What kind of feedback loop are rocks and how long does it take?
negative
millions of years
