41-50

Question 1

Which sector in China is the majority of the final (primary+secondary) energy spent
on?

Answer 1

Industry

Question 2

What fraction of the electricity in China is generated by coal?

Answer 2

60%

Question 3

A reason why China is a big CO2 emitter is that China is the world’s leading producer of

Answer 3

cement

Question 4

In 2022, roughly what fraction of China’s CO2 emission did it come from the use of coal?

Answer 4

80%

Question 5

If the US is to reduce its total CO2 emission per GDP dollar by 80% in 2050 relative to 2005, then after taking a 1.5% inflation into account, the actual reduction required has to be around

Answer 5

80%

Question 6

In the lecture, we talked about four major ways through which Earth balances the input
energy it receives from the Sun: albedo, infrared radiation, latent heat, and

Answer 6

sensible heat

Question 7

One of the keys of the greenhouse effect is that

Answer 7

infrared radiation from the surface cannot pass through the atmo- sphere.

Question 8

Given that the solar radiation has a power of 1360 W m−2 and the Earth is a rotating sphere, what is the area-averaged power received by the Earth’s top of the atmosphere?

Answer 8

340 W m^−2

Question 9

The Earth receives solar radiation from the Sun mostly in the visible wavelength range.
At what dominant wavelength range does the Earth radiate energy back to the space?

Answer 9

Infrared

Question 10

Which of the following is the most abundant greenhouse gas in the Earth’s atmosphere?

Answer 10

H2O