ERTH 1000E MODULE E QUIZZES
Today the timing of peak snowmelt runoff in New England streams is happening _____
than it typically occured historically.
a. at the same time
b. later
c. earlier
d. significantly later - Answer -c. earlier
Which of the following are the major drivers of global (eustatic) sea-level rise, both in
modern day, as well in other parts of Earth history?
melting of continental glaciers
changes in oceanic circulation
melting of sea-ice
thermal expansion of seawater - Answer -melting of continental glaciers
thermal expansion of seawater
Let's return to a concept we first discussed in Unit 8 (Earth Systems Science): radiative
forcing.
Radiative forcing refers to components of the earth system that can change the amount
of energy from the Sun that reaches the Earth's surface (measured it Watts per square
meter). Understanding the different radiative forcings is key to making robust predictions
about Earth's climate system.
Earth has net positive radiative forcings, meaning that we have more energy in the
climate system that we would have if our climate was only determined by solar
radiation. This is a good thing too, because without those radiative forcings, Earth's
average surface temperature would be about -15 degrees C, or 5 degrees F, whereas
now it's closer to 15 degrees C, or 60 degrees F.
Radiative forcings are displayed in the diagram below. Solar radiation comes in at the
top of the atmosphere, but some of it is lost by being reflected, eithe - Answer -about
half
This question refers to the figure in Question 3. What climate modelers do is generate
scenarios in which radiative forcings are changed. More energy at the Earth's surface
means that the Earth warms up, whereas less energy at the Earth's surface means that
the Earth cools down.
Can you for example predict which of the following changes in radiative forcings would
warm the Earth's surface up? (select all that apply)
increased evapotranspiration
decreased reflectivity (albedo) of the Earth's surface
increased solar radiation
decreased Greenhouse Gases
increased aerosols - Answer -decreased reflectivity (albedo) of the Earth's surface
increased solar radiation
, To understand the impact of anthropogenic (human-made) emissions, and be able to
predict how changing anthropogenic emissions will affect the climate in the future,
climate modelers must first understand the net effect of individual radiative forcings.
Below, you see a diagram that constrains the effect of different radiative forcings. Note
the error bars associated with each of the forcings.
Which of the following forcings have a net warming effect on the Earth's surface? (select
all that apply)
Carbon dioxide (CO2)
Land-use change
Methane (CH4)
Changes in clouds due to aerosols
Aerosols - Answer -Carbon dioxide (CO2)
Methane (CH4)
Climate modelers are then capable of looking back in time at known changes in
radiative forcings and see how the climate responded to these changes. For example,
below is the evolution of radiative forcings since 1750. Above the dark line means that
these forcings increase effective radiative forcing, whereas below the dark line means
that they decrease effective radiative forcing. Note that the two dotted lines represent
actual changes in radiative forcing (black, total) and all anthropogenic radiative forcings
combined (red). (ERF = effective radiative forcing, WMGHG = well-mixed greenhouse
gases, int. = interaction)
Before the Great Acceleration, what is the forcing that seems to have been able to
change global climate the most on a year by year basis?
carbon dioxide
land-use change
volcanic eruptions
solar radiation - Answer -volcanic eruptions
After this, incorporating the uncertainty related to the effect of radiative forcings has
actually less to do with how the climate responds to changes in radiative forcing, but
more with what policies are adopted. See for example below the graph showing the
global surface warming over the next century. The shaded area represents modeled
uncertainty, whereas the different colored lines represent different policy scenarios.
By the year 2100, what is the Global Surface Warming difference (in degrees C)
between the most "optmistic" and the most "pessimistic" scenario? - Answer -3.5
Interestingly, while the near future climate is so dependent on politics and culture that is
hard to predict, many climatic trends in the distant future are easier to predict, because
they rely on predictable astronomical or geological trends.
Have a look at the Timeline of the Far Future. Note that for each "event" there are
different mechanisms associated with it and therefore different levels of certainty. For
example, Earth's orbital variation is cyclical and entirely predictable, whereas the
recurrence rate of a supervolcano eruption is simply based on previous rates of
eruptions and is therefore not cyclical.
Today the timing of peak snowmelt runoff in New England streams is happening _____
than it typically occured historically.
a. at the same time
b. later
c. earlier
d. significantly later - Answer -c. earlier
Which of the following are the major drivers of global (eustatic) sea-level rise, both in
modern day, as well in other parts of Earth history?
melting of continental glaciers
changes in oceanic circulation
melting of sea-ice
thermal expansion of seawater - Answer -melting of continental glaciers
thermal expansion of seawater
Let's return to a concept we first discussed in Unit 8 (Earth Systems Science): radiative
forcing.
Radiative forcing refers to components of the earth system that can change the amount
of energy from the Sun that reaches the Earth's surface (measured it Watts per square
meter). Understanding the different radiative forcings is key to making robust predictions
about Earth's climate system.
Earth has net positive radiative forcings, meaning that we have more energy in the
climate system that we would have if our climate was only determined by solar
radiation. This is a good thing too, because without those radiative forcings, Earth's
average surface temperature would be about -15 degrees C, or 5 degrees F, whereas
now it's closer to 15 degrees C, or 60 degrees F.
Radiative forcings are displayed in the diagram below. Solar radiation comes in at the
top of the atmosphere, but some of it is lost by being reflected, eithe - Answer -about
half
This question refers to the figure in Question 3. What climate modelers do is generate
scenarios in which radiative forcings are changed. More energy at the Earth's surface
means that the Earth warms up, whereas less energy at the Earth's surface means that
the Earth cools down.
Can you for example predict which of the following changes in radiative forcings would
warm the Earth's surface up? (select all that apply)
increased evapotranspiration
decreased reflectivity (albedo) of the Earth's surface
increased solar radiation
decreased Greenhouse Gases
increased aerosols - Answer -decreased reflectivity (albedo) of the Earth's surface
increased solar radiation
, To understand the impact of anthropogenic (human-made) emissions, and be able to
predict how changing anthropogenic emissions will affect the climate in the future,
climate modelers must first understand the net effect of individual radiative forcings.
Below, you see a diagram that constrains the effect of different radiative forcings. Note
the error bars associated with each of the forcings.
Which of the following forcings have a net warming effect on the Earth's surface? (select
all that apply)
Carbon dioxide (CO2)
Land-use change
Methane (CH4)
Changes in clouds due to aerosols
Aerosols - Answer -Carbon dioxide (CO2)
Methane (CH4)
Climate modelers are then capable of looking back in time at known changes in
radiative forcings and see how the climate responded to these changes. For example,
below is the evolution of radiative forcings since 1750. Above the dark line means that
these forcings increase effective radiative forcing, whereas below the dark line means
that they decrease effective radiative forcing. Note that the two dotted lines represent
actual changes in radiative forcing (black, total) and all anthropogenic radiative forcings
combined (red). (ERF = effective radiative forcing, WMGHG = well-mixed greenhouse
gases, int. = interaction)
Before the Great Acceleration, what is the forcing that seems to have been able to
change global climate the most on a year by year basis?
carbon dioxide
land-use change
volcanic eruptions
solar radiation - Answer -volcanic eruptions
After this, incorporating the uncertainty related to the effect of radiative forcings has
actually less to do with how the climate responds to changes in radiative forcing, but
more with what policies are adopted. See for example below the graph showing the
global surface warming over the next century. The shaded area represents modeled
uncertainty, whereas the different colored lines represent different policy scenarios.
By the year 2100, what is the Global Surface Warming difference (in degrees C)
between the most "optmistic" and the most "pessimistic" scenario? - Answer -3.5
Interestingly, while the near future climate is so dependent on politics and culture that is
hard to predict, many climatic trends in the distant future are easier to predict, because
they rely on predictable astronomical or geological trends.
Have a look at the Timeline of the Far Future. Note that for each "event" there are
different mechanisms associated with it and therefore different levels of certainty. For
example, Earth's orbital variation is cyclical and entirely predictable, whereas the
recurrence rate of a supervolcano eruption is simply based on previous rates of
eruptions and is therefore not cyclical.
