Earth's climate system 4.2 review quiz

Which of the following statements best describes the average solar energy budget for incoming radiation? (percentages rounded)

20% absorbed by atmosphere and clouds, 30% reflected back to space, 50% absorbed by land and oceans.

What is a greenhouse gas?

Any gas that absorbs relatively high amounts of energy from solar radiation.

Why does the Earth have seasons?

Because earth's axis is tilted

The three Milankovitch cycles:

Create variations in the amount of solar radiation reaching Earth's surface

When the Earth is at maximum eccentricity the orbital shape is __________.

Eliptical

True or False: The following is an example of a negative feedback system: increased melting of permafrost leads to increased methane emissions which causes more permafrost to melt.

False

How do scientists know the value of atmospheric carbon dioxide concentration in preindustrial times?

Gas bubbles trapped in ice cores can be extracted and measured for their gas concentrations directly

Which of these is a major limitation of instrumental records to understand long term climate variability?

Instrumental records are not long enough to capture the full range of natural climate variability

Which of the following data sources is NOT a climate proxy?

Temperatures measurements made using thermometers

Which of the following Milankovitch cycles is stated correctly?

The tilt of the earth's axis of rotation varies between 22.2-24.50 over 41,000 year cycles

Analyzing oxygen isotope proportions from an ocean sediment core, a graduate student finds that the concentration of O18 in the ocean was lower at some time in the past than it is today. What would that tell the student about Earth's climate at that time?

Warmer than today

Think about what you know about albedo: At times when more continental land area is found near the poles, Earth would likely be ________ when continents are concentrated along the Equator.

cooler than

During glacial periods, the concentration of 18O in the oceans will be ______ compared to interglacial periods.

higher

If the Earth were tilted at 30o on its axis instead of 23.5o seasons on Earth would be ____.

more intense