Topic 2.2: Greenhouse Effect Questions

Which radiation do greenhouse gases absorb most strongly?

The emission curve of a black body is drawn as intensity against wavelength. The body is cooled.

What happens to the area under the curve?

A region becomes covered in fresh snow.

What happens to its albedo and to the intensity it absorbs?

Nitrogen makes up most of the atmosphere but is not a greenhouse gas.

Which statement explains this?

A geography student researching climate change reads that human activity since the Industrial Revolution has strengthened the natural greenhouse effect, leading to global warming.

Which human activity is the main cause of this enhanced greenhouse effect?

A black body is heated from 400 K to 800 K.

Which describes the change in its emission curve?

Which change increases the Earth's albedo?

A satellite measures that a region scatters 4.2 × 10¹⁶ W of solar power back to space out of 1.2 × 10¹⁷ W of incident solar power.

Calculate the albedo of this region.

A region on the equator has the Sun directly overhead at midday.

The intensity of solar radiation arriving at the top of the atmosphere is 1360 W m⁻², and the atmosphere has an albedo of 0.30.

Assuming no absorption by the atmosphere, what is the intensity of solar radiation reaching the surface?

Sunlight of intensity S falls on the top of an atmosphere whose albedo is 0.20, with the Sun directly overhead.

What intensity reaches the ground below?

A textbook states that without the greenhouse effect the Earth's average surface temperature would be around −18 °C instead of about 15 °C.

Estimate, in kelvin, how much warmer the greenhouse effect makes the surface, and state what this shows about the greenhouse effect.

A solar-powered space probe travels away from the Sun.

State why its solar panels deliver less power as it travels.

Define what is meant by a black body, and outline why a real star is a good approximation to one.

Why does sunlight pass through the atmosphere while much of the Earth's outgoing radiation is absorbed?

State what is meant by the albedo of a surface.

With the Sun overhead, 1200 W m⁻² arrives at the top of the atmosphere. 30 % is reflected and nothing is absorbed by the air.

What intensity reaches the ground?

Identify which of the following statements about Earth's albedo are correct.

I. Earth's albedo can change with the time of day.
II. Earth's albedo depends on the latitude of the location.
III. Earth's albedo increases when cloud cover increases.

A 4.0 m² solar panel receives sunlight of intensity 0.80 kW m⁻² and converts 15 % of it into electrical energy.

What electrical power does it deliver?

State one reason why the intensity of sunlight at the Earth's surface is less than the solar constant.

Betelgeuse is a red supergiant at about 3600 K.

Determine where its black-body curve peaks, and the part of the spectrum that lies in.