Midterm 1 Quizes 1,2,3 Flashcards
Roughly how large is a 1˚C warming in Fahrenheit?
0.5˚F
1˚F
2˚F
3˚F
2˚F
Which emits radiation with the shortest wavelengths?
An ice cube
The warm yellow tip of a flame
The hotter blue center of a flame
Not enough information to answer
The hotter blue center of a flame
When was the greenhouse effect discovered?
1820s
1920s
1950s
1970s
1820s
The atmosphere is mostly _______________________to solar radiation and _____________________ to Earth’s radiation.
Absorptive, transmissive
Transparent, opaque
Absorptive, reflective
Blocking, reflective
Transparent, opaque
How does CO2 warm the planet?
It absorbs incoming sunlight, warming the atmosphere and delivering heat to the surface
It absorbs earth’s outgoing radiation and re-emits it back toward the surface
It is absorbed by the oceans, increasing their heat content
It produces its own heat that adds to the energy delivered by the sun
It absorbs earth’s outgoing radiation and re-emits it back toward the surface
If you took away the atmosphere’s greenhouse effect, Earth would be ________________.
the same temperature
10 to 20°F warmer
10 to 20°F colder
50 to 60°F colder
50 to 60°F colder
For gas molecules to absorb infrared radiation, they need to have their electric charge be _____________________.
Symmetrical on both sides of the molecule
Lopsided toward one side of the molecule
Lopsided toward one side of the molecule
What is the current status of Earth’s energy balance?
Satellites and ocean warming both confirm that more energy is coming into the climate system than escaping it out to space
The climate system must be in energy balance, otherwise a vicious cycle would have taken over and warming would have spiraled out of control
Scientists suspect the climate system is gaining energy but there is no way to measure it and be sure
We do not know
Satellites and ocean warming both confirm that more energy is coming into the climate system than escaping it out to space
If the atmosphere and ocean stopped circulating __________________.
the tropics would be warmer and the poles would be colder
the tropics would be colder and the poles would be warmer
the tropics would be colder and the poles would be colder
the tropics would be warmer and the poles would be warmer
The tropics would be warmer and the poles would be colder
-Which does not affect global average temperature (i.e., the global energy balance)?
Strength of the sun
Atmospheric circulation
Earth’s albedo
Strength of the greenhouse effect
Atmospheric circulation
The Arctic is warming faster than the tropics, reducing the pole-to-equator temperature difference. What should this tend to do to atmospheric circulation?
Strengthen it
Weaken it
Reverse it
Weaken it
What would happen to the atmospheric wind belts if the planet spun backwards?
The winds would not change
The winds might stop
The winds would reverse
The winds would strengthen
The winds would reverse
Where are the surface and deep ocean best connected (i.e., able to move water vertically)?
the tropics due to the warm surface waters
the poles due to the cold surface waters
the mid-latitudes due to fronts in the atmosphere
the Indian Ocean due to the strong seasonal monsoons
the poles due to the cold surface waters
-Which is true?
Clouds and rain tend to form where air rises
It tends to be clear and sunny where air rises
Warm air cannot hold much water vapor, a key greenhouse gas
Warming an air mass increases its relative humidity
Clouds and rain tend to form where air rises
Which sets up the conditions for cold Arctic air to spill south over the US east coast in winter?
A straight jet stream
A wavy jet stream
A fast jet stream
A reversed jet stream
A wavy jet stream
What would happen to the salinity of the North Atlantic and the strength of the deep ocean conveyor belt if western North America was covered by flat plains instead of the Rocky Mountains?
Saltier North Atlantic and weaker conveyor circulation
Saltier North Atlantic and stronger conveyor circulation
Fresher North Atlantic and stronger conveyor circulation
Fresher North Atlantic and weaker conveyor circulation
Fresher North Atlantic and weaker conveyor circulation
If the deep ocean conveyor belt stopped circulating (i.e., surface waters stopped sinking into the depths of the ocean), global surface temperature would ___________________.
warm even faster
warm more slowly
cool
stop changing
warm even faster
Where has >90% of the heat gained due to Earth’s energy imbalance gone over the past 50 years?
It has been added to vegetation
Warming the atmosphere
Melting glaciers
Warming the oceans
It has been reflected back to space
Warming the oceans
Where has a “cold blob” been observed in recent years, suggesting the global ocean conveyor belt may be weakening?
The North Atlantic
Around Antarctica
The bottom of of the Pacific
This is a trick question; there is no cold blob because the world has been warming everywhere
The North Atlantic
Approximately how much would global sea level rise if all of the ice on the planet melted?
0 feet
10 feet
20 feet
200 feet
200 feet
Approximately how much would global sea level rise if all of the sea ice in the Arctic Ocean melted?
0 feet
10 feet
20 feet
200 feet
0 feet
Which is the largest potential contributor to sea level rise?
Mountain glaciers
Ice sheets
Ocean warming and expansion
Sea ice
Ice sheets
How much would sea level rise around Greenland if the Greenland Ice Sheet melted?
Less than the global average
The same as the global average
More than the global average
Less than the global average
How much has global sea level changed over the past century?
It has fallen 3 inches
It has not changed
It has risen 8 inches
It has risen 5 feet
It has risen 8 inches
Why is the Thwaites Glacier in West Antarctica thought to be especially vulnerable to climate change?
It has more crevasses (cracks) than any glacier in the world
Meltwater drains underneath it lubricating its flow into the sea
Its surface is covered in dark dust, so it absorbs lots of sunlight
It sits on land beneath sea level that slopes inward toward the center of the ice sheet
It sits on land beneath sea level that slopes inward toward the center of the ice sheet
If human fossil fuel emissions continue at the current rate throughout this century, atmospheric CO2 concentrations during the rest of your life will never be as low as they are today.
True
False
True
Will chemical weathering of rocks remove the CO2 humans have emitted to the atmosphere?
Yes, and this should reverse global warming by 2100
Yes, but only after many thousands of years because it is a very slow process
No, a warming climate will prevent rocks from weathering and consuming CO2
No, weathering of rocks will release more CO2 into the atmosphere
Yes, but only after many thousands of years because it is a very slow process
Approximately how much of our CO2 emissions has nature absorbed from the atmosphere?
None of it
Half of it
All of it
We do not know
Half of it
Which contains the most carbon?
Atmosphere
Plants and soils
Surface ocean
Deep ocean
Deep ocean
Which is true about how the carbon cycle worked in the centuries before humans started emitting carbon (i.e., before the Industrial Revolution)?
Carbon did not cycle between different reservoirs (land, ocean, atmosphere), so the level of CO2 in the atmosphere was stable
Carbon flows between different reservoirs were in balance, so the level of CO2 in the atmosphere was stable
More CO2 was flowing into than out of the atmosphere, so the level of CO2 in the atmosphere was rising
There was no CO2 in the atmosphere until humans started emitting it
Carbon flows between different reservoirs were in balance, so the level of CO2 in the atmosphere was stable
Which of the following is an example of a climate feedback?
Melting glaciers delivering freshwater to the North Atlantic and slowing the deep ocean conveyor belt circulation
Thawing Arctic soils releasing greenhouse gases to the atmosphere
Melting sea ice increasing absorption of solar radiation
Warmer temperatures allowing insect populations to rise and kill carbon-absorbing forests
All of the above
None of the above
All of the above
There is no way to compare how much different kinds of forcings affect the climate because they are in different units (e.g., CO2 concentrations are in parts per million, forest cover is in square miles, solar output is in watts, etc.), so one cannot do an “apples to apples” comparison between them.
True
False
False
Doubling atmospheric CO2 levels by itself (i.e., only considering its direct effect) would cause the planet to warm by roughly how much?
0°C
1°C
2.5°C
4°C
1°C
Climate could continue changing all on its own even after humans stop emitting greenhouse gases due to feedback loops.
True
False
True
Water vapor is a key greenhouse gas, but it cannot force the climate to change, it can only amplify an already ongoing climate change as a feedback.
True
False
True
What is the major source of uncertainty in predicting how much global warming will occur due to doubling atmospheric CO2 levels?
how much feedback loops will amplify or diminish the initial warming from CO2
how large of a forcing 2x CO2 is (i.e., how much extra radiation it will trap)
how much shortwave radiation from the sun the CO2 will absorb
there is very little uncertainty
how much feedback loops will amplify or diminish the initial warming from CO2
How much will doubling atmospheric CO2 likely change global temperature (i.e., “climate sensitivity”)?
0-1°C colder
0-1°C warmer
1.2-1.3°C warmer
2.5-4°C warmer
5-10°C warmer
2.5-4°C warmer
Feedbacks in the climate system tend to __________________ the direct warming from rising greenhouse gases.
amplify
counteract
leave unchanged
amplify
Let’s say Earth’s climate sensitivity is 3°C. If CO2 concentrations reach twice their preindustrial level in 2050, how much warmer will global temperature be that year?
3°C
less than 3°C
more than 3°C
less than 3°C
A tipping point is called that because a system always tips abruptly once the threshold point is crossed.
True
False
False
A tipping point simply refers to a system that will change states once a threshold is crossed, but it may not happen abruptly if the processes involved take a long time. For example, we may have crossed the tipping point between online shopping versus brick-and-mortar retail stores, but shopping malls will not instantly disappear (if they ever do).
There are thought to be many tipping points throughout the climate system, including the ocean, the ice, and the land, and from the poles to the tropics.
True
False
True
As we discussed in class, major tipping points in the climate system include (but not limit to) melt of Greenland ice sheet, boreal forest dieback, change in ENSO amplitude or frequency, etc.
Some tipping points may be temporarily crossed without causing the system to jump to a new state if the forcing is turned back down quickly enough.
True
False
True
Think when you are canoeing and just about to flip, if you lean to the other direction immediately, you might not flip over.
Which of the following is NOT true about climate tipping points?
They could cause abrupt shifts in the climate
They can be precisely predicted
They could have large impacts on people and ecosystems
They could be triggered by small amounts of warming beyond a critical threshold
They can be precisely predicted
Climate only varies if it is pushed by an external forcing.
True
False
False
Climate also varies due to internal or unforced variability, e.g., temperature variability at a given location across different years in a short term.
Internal variability within the climate system is organized into recurring patterns or modes.
True
False
True
Internal unforced variability tends to be organized into large-scale patterns or “climate modes” that oscillate back and forth over years to decades. Examples are ENSO, AMO, and NAO.
Over what time scale does internal climate variability occur?
years
several years
decades
all of the above
All of the above
Internal climate variability could occur on time scales of years to decades.
The largest driver of year-to-year temperature variability at any given location is usually an external forcing, such as the steadily rising concentration of atmospheric CO2.
True
False
False
At a given location, the largest driver of year-to-year temperature variability is usually internal unforced variability. Internal variability causes the largest fluctuations at local scales by sloshing heat from one place to another.
The global temperature record shows numerous 5 or 10-year intervals of stable or declining temperatures over the past half century.
True
False
True
This is true - have a closer look at the figure on slide 22 of the “8. Forced and unforced variability” PowerPoint.
The longer you observe the climate, the more confident you can be if there is a trend in it.
True
False
True
Internal variability largely cancels out globally and over longer time scales, so it is easiest to see forced trends in global temperature over decades.
Arctic permafrost thaw and carbon release is an example of an irreversible tipping point.
True
False
True
The tiniest error in estimating what part of the atmosphere is doing right now could lead to a completely different forecast of what the weather might be in a couple weeks due to chaos.
True
False
True
This is true - a prediction with errors could be completely different from what is going to happen.
The climate will always vary even if no external forcing is driving it.
True
False
True
This is true because we still need to consider internal unforced variability.
The poles have larger year-to-year unforced variability than the tropics. If both experience the same rate of forced climate warming, where would you expect this warming trend to be detectable first?
Poles
Tropics
The trend would become clear in both regions at the same time
It is unclear
Tropics
Because the poles have larger unforced variability so they are less sensitive to forced climate warming. Likewise, tropics have smaller unforced variability so they are more sensitive to forced climate warming.
The whole world likely warms up and cools down over the Ice Ages together because of _________________________.
Group of answer choices
changes in global average sunlight received due to cycles in the earth’s orbit
changes in atmospheric CO2 concentrations
changes in the strength of the deep ocean conveyor belt
Changes in solar output over 20, 40, and 100 thousand year sunspot cycles
Changes in atmospheric CO2 concentrations
What is the initial trigger at the end of an ice age?
The sun gets brighter
The ocean conveyor belt strengthens
El Niños become more frequent
The earth’s orbit changes causing stronger Arctic sunlight to melt ice sheets
The earth’s orbit changes causing stronger Arctic sunlight to melt ice sheets
See the reading. The end of an ice age starts when increasing Arctic summer sunlight melts ice sheets (turning off the deep ocean conveyor by freshening the North Atlantic, in turn leading to CO2 coming out of the ocean around Antarctica).
Which of the following does NOT vary in sync with the growth and decay of Arctic ice sheets over ice age cycles?
Global sea level
Atmospheric CO2 levels
Antarctic temperatures
The intensity of summer sunlight in the Southern Hemisphere
The intensity of summer sunlight in the Southern Hemisphere
The intensity of summer sunlight in the Southern Hemisphere depends on Milankovitch Cycles (precession, obliquity, and eccentricity).
There had NOT been abrupt changes in Earth’s climate until today.
True
False
False
There were dozens of abrupt climate events during the last ice age.
The atmospheric CO2 concentration is currently higher than it has been for at least 800,000 years.
True
False
True
The current CO2 concentration is ~420 ppm, much higher than the 180-280 ppm range over ice age cycles during the past 800,000 years.
