Unit 2 - CC Introduction and Impacts Flashcards
Are human-caused atmospheric phenomena climate change?
no, we are talking about natural sources of variation
4 things that are NOT results of climate change?
-hole in ozone layer
-smog/pollution
-acid rain
-ocean acidification
weather or climate?
thunderstorm
weather
weather or climate?
avg # of intense precipitation events per year
climate
weather or climate?
a late spring freeze event
weather
weather or climate?
the average date of the last freeze in spring continues to get earlier
climate
weather or climate?
servere hurricane
weather
weather or climate?
an upward trend in the 30 year average of the frequency and intensity of hurricanes
climate
Climate change doesn’t cause hurricanes or storms to form, it just increases the _____ of it happening.
likelihood/frequency
definition: mixture of gases that hold heat to the surface of the Earth
atmosphere
Without the atmosphere, would Earth be warmer or colder?
colder (drop from 60 to 0 degrees C)
When energy from the sun warms the Earth what are the two options for this energy?
(1) escaping back into space
(2) held by greenhouse gases in atmosphere
What is the main effect of the greenhouse effect?
to warm the Earth’s surface and lower atmosphere
In the Greenhouse effect, what type of radiation is emitted from the Earth’s surface?
infrared radiation
When energy is absorbed and then reradiated by the Earth’s surface, what happens?
it gets more disordered/looses energy and the low energy/infrared radiation can’t escape as well
What are the main steps in the Greenhouse Effect?
(1) incoming, short wavelength radiation from the sun
(2) once Earth is warmed by the sun, all objects radiate heat in the form of long wave infrared radiation
(3) long wave infrared radiation is ABSORBED by greenhouse gases in the atmosphere
(4) when GHG molecules stop vibrating, they are reradiated in ALL directions
What does the strength of the Greenhouse effect depend on?
concentrations of different GHG
How is it possible for the Earth’s energy budget to have a stable temperature?
energy entering = energy exiting
In Earth’s energy budget, what can happen to incoming solar energy?
(1) reflected by atmosphere (6%)
(2) reflected by clouds (20%)
(3) reflected from Earth’s surface (4%)
(4) absorbed by atmosphere (16%)
(5) absorbed by clouds (3)
(6) absorbed by land and oceans (51%)
What are 3 different options for incoming solar energy?
(1) absorption: atmosphere, land or water causing warming
(2) reflected: bounced back into space without causing warming
(3) radiated: passively escapes into space
What is the term for natural and VERY long-term fluctuations in the sun’s intensity? Responsible for ice ages.
milankovitch cycles
What is the main cause of milankovitch cycles?
changes in the Earth’s orbit that in turn changes the Earth’s temperature
About how long are Milankovitch cycles?
100,000 years
What is the main way the amount of incoming solar radiation can change due to changes in Earth’s orbit?
milankovitch cycles
How long ago was the end of the last ice age?
10-15,000 years ago
definition: amount of sunlight (solar radiation) reflected by a surface
albedo
Things with ____ albedo:
-light colored
-reflects more light/energy
-ex: ice, snow, clouds
high
Thing with high albedo reflect ___% of incoming energy while things with low albedo ___% of incoming energy.
80; 10
Things with ____ albedo:
-dark colored
-absorb more light/energy
-ex: water, forest, dark soil
low
Is the sea ice albedo feedback positive or negative?
positive
Describe the sea ice albedo feedback?
warming temperature tends to decrease ice cover and hence decrease the albedo, increasing the amount of solar energy absorbed and leading to more warming
In the sea ice albedo feedback, what happens when ice starts to melt and reveal seawater beneath it?
the albedo decreases and the dark water absorbs more heat further melting sea ice
______ feedback: promotes changes that lead back toward equilibrium
negative
_______: systems that promotes further change toward an extreme (amplification of a stimulus)
positive
What is a common example of a negative feedback (overshoot, undershoot, overshoot behavior)?
predator-prey dynamics
What is a common example of a positive feedback (build, build, build, CRASH behavior)?
labor, avalanche
What is the result of the albedo positive feedback cycle?
snowball earth
Describe what snowball Earth was.
as more ice covers the globe, the planet becomes more reflective, or higher in albedo which further cools the surface for more ice to expand
How can volcanic activity temporarily cool the planet? Can all eruptions do this?
ash can reflect sunlight high in the atmosphere before it even comes close to the surface of the Earth; No, only ones with the right sized particles made out of proper materials
Can small increases in GHGs increase temp?
yes
What is the main difference between the natural and human enhanced Greenhouse Effects?
less heat ESCAPES into space & there is more reemitted heat in the human enhanced Greenhouse Effect, contributing to a warmer Earth
In the ______ Greenhouse effect, equal amounts of energy are coming in and leaving.
natural
In the ______ Greenhouse effect, more energy is coming in than leaving.
human enhanced
What % of the atmosphere is made of GHGs?
less than 0.1% (trace gases)
What are the trace gases?
Carbon dioxide (93%)
Methane (0.4%)
Nitrous Oxide (0.08%)
What are natural sources of Carbon Dioxide?
respiration, volcanoes, decomposition, fires (carbon cycle)
What are natural sources of Nitrous Oxide (N20)?
Nitrogen cycle product, fires, car emissions
What are natural sources of methane?
digestion, geologic leaching, melting permafrost
What are natural sources of fluorinated compounds (F gases, SF6, CFCs, HFCs)?
none, all are synthetic
What are natural sources of water vapor?
water cycle, combustion
What are anthropogenic sources of CO2?
fossil fuel burning (mostly coal), cement curing, land use conversion
What are anthropogenic sources of N2O?
gasoline burning, agricultural fertilization