// hw questions

Question 1

We know that the Earth is warming because,

Answer 1

• Mountain glaciers are melting,
• sea ice is melting,
• sea surface temperature is increasing,
• and surface air temperature is increasing

Question 2

Svante Arrenhius, the swedish scientist,

Answer 2

Did the first calculation of warming by CO2 increase.

Question 3

Between 1980 and 2016 the Northern Hemisphere warmed faster than the Southern Hemisphere.

Answer 3

True (because more land mass)

Question 4

• Between 1940 and 1980 global mean land temperature

Answer 4

remained almost constant (because of limited use of GH gases)

Question 5

In 2011 a group led by Berkeley professor Richard Muller did an independent analysis of the global surface temperature record and found that,

Answer 5

• Surface air temperature had increased,
• over the past 50 years the land temperature warmed by 0.9 C,
• while stations considered to be ‘poor’ might be less accurate, they record the same warming as other stations,
• the urban heat island effect does not bias the global trend of temperatures

Question 6

We know that the increase in CO2 in the atmosphere is caused by fossil fuel burning because.

Answer 6

• the carbon-13 abundance in the atmosphere is decreasing,
• it rises simultaneously with fossil fuel use,
• the molecular oxygen in the atmosphere is decreasing,
• the carbon-14 (radiocarbon) in the atmosphere has decreased

Question 7

The CO2 concentration in the Northern Hemisphere atmosphere (e.g. Mauna Loa, HI) shows the following seasonal variation.

Answer 7

Maximum in Spring, minimum in Fall

Question 8

Which of the following is NOT TRUE?

Answer 8

Sea level rises when sea ice melts (because it’s already in the ocean). the rest are true….

• Sea level rises when icebergs slide into the ocean.
• Sea level rises when the ocean warms. (water expands)
• Sea level rises when mountain glaciers melt.

Question 9

Which of the following is NOT TRUE?

Answer 9

Hotter bodies emit longer (it’s shorter!) wavelength radiation. the rest are true…

• Hotter bodies emit more energetic photons.
• The Earth emits thermal infrared radiation with wavelengths around 10 microns, or 10000 nanometers.
• Hotter bodies emit more blackbody radiation

Question 10

Which of the following is NOT an important cause for the strong greenhouse effect that keeps the surface temperature of Earth warmer than it would be without an atmosphere containing greenhouse gases.

Answer 10

The atmosphere reflects infrared radiation. the rest are important causes…

• The atmosphere is relatively transparent to solar radiation. (so warms fast).
• The surface absorbs solar radiation and emits thermal infrared radiation. (keeps GHG in atmosphere longer)
• The atmosphere absorbs and emits infrared radiation

Question 11

Are both statements true and/or false?: If there were no natural greenhouse effect, the surface temperature would be cooler . If there were no enhanced greenhouse effect due to emissions of greenhouse gases, the surface temperature would be cooler .

Answer 11

true and true

Question 12

The climate sensitivity is often quantified as?

Answer 12

Increase in global mean surface temperature from doubling the preindustrial CO2 level.

Question 13

What is the most abundant and important greenhouse gas and why is it not driving current climate change?

Answer 13

Water vapor is the most abundant but it has a short residence time, meaning it is continually lost to condensation and precipitation.

Question 14

Which greenhouse gas contributes the most to the current greenhouse gas radiative forcing relative to pre-industrial times?

Answer 14

CO2

Question 15

Significant upward trend in solar activity since 1978 is the major driving force for recent global warming.

Answer 15

False. (almost at a sunspot minimum, yet the earth is hot af).

Question 16

Water vapor is a very effective absorber and emitter of thermal infrared radiation because,

Answer 16

It is a bent triatomic molecule

Question 17

In order for a volcanic eruption to effectively cool the surface of Earth, it must have the following characteristic,

Answer 17

• It must be highly explosive and put material in the stratosphere
• It should happen in the tropics where it lasts longer and more insolation is present
• Its efluent must contain a large amount of SO2, which then converts to H2SO4 aerosols

Question 18

For a time horizon of 100 years in the future, Methane has a global warming potential 25 times that of CO2 because

Answer 18

A kilogram of Methane added to the atmosphere produces a much larger climate forcing than a kilogram of carbon dioxide

Question 19

The climate forcing associated with the 11-year solar cycle has a magnitude, peak to peak of about

Answer 19

0.2 Wm-2

Question 20

Global Dimming refers to

Answer 20

An observed reduction in downward solar radiation at the Earth’s surface between about 1950 and 1980

Question 21

Which of the following is NOT TRUE about the global distribution of net incoming radiation, which equals absorbed solar minus outgoing infrared radiation?

Answer 21

The turning point from net gain to net loss is 23.5 degrees latitude. The rest are true…

• Motions in the atmosphere and ocean work to distribute the resultant energy imbalance
• The polar regions experience a net loss
• The tropics experience a net gain

Question 22

• Over the Sahara and Arabian Deserts the biggest contributions to the surface energy balance come from

Answer 22

Radiative heating and sensible cooling

Question 23

Which is correct about the El Niño Southern Oscillation (ENSO)?

Answer 23

Weaker trade winds are associated with El Niño phase.

Question 24

What is the primary reason the ocean has a greater overall heat content than the atmosphere?

Answer 24

Water has a higher heat capacity than air, and the ocean has more mass than the atmosphere..

Question 25

Which of the following are NOT TRUE about the poleward transport of energy by the ocean and atmosphere

Answer 25

The atmospheric transport peaks near the subtropical jet at 30N and 30S (actually about 45 N and S). the rest are true…

• The atmosphere does more transport than the ocean in middle latitudes.
• The ocean transport peaks nearer the equator than the atmospheric transport.
• The total peaks at about 40N and 40S.

Question 26

Which statement is false?

Answer 26

The equator receives more radiation during solstice than during equinox. the rest are true…

• At equinox the sun is directly over the equator.
• During equinox the days are the same length north and south of the equator.
• During solstice the sun is 23.45 degrees north or south of the equator.

Question 27

In the annual mean, over the Sahara and Arabian Deserts

Answer 27

• The mean motion of the air is downward,
• the surface albedo is very high,
• the surface is hot and the sky is clear,
• the net radiation at top-of-atmosphere is negative, the deserts lose energy

Question 28

The angular momentum of the atmosphere is greatest

Answer 28

At the equator if the wind is zero or westerly.

Question 29

The two largest terms in the global mean atmospheric energy balance are,

Answer 29

Heating by condensation and cooling by radiation

Question 30

The largest terms in the global mean surface energy balance are,

Answer 30

Radiative heating and evaporative cooling