▶ Your Answer :
The reading passage contends that the cause
of Little Ice Age can be fully explained by three theories. On the other hand,
the lecture contradicts the reading by saying that none of the three theories
are convincing.
First of all, the lecturer argues that it
is impossible to say that the decrease amount of solar radiation caused the
Little Ice Age. Recent observations showed that there are few amount of Sun Spot
on the surface. However, the total energy of solar radiation has not been
decreasing. Therefore, the correlation between the sun spot and solar radiation
is not true. This casts doubt on the reading passage’s claim that the lessened
solar radiation due to fewer sunspots caused the Little Ice Age.
Also, the speaker asserts that the Little
Ice Age was not triggered by a massive volcanic eruption. An enormous volcanic
eruption didn’t’ affect the global climates. This is because the ash and dust
would not have lasted few years, so it is not enough time to affect the global
weather. However, the Little Ice Age continued from 1300s to late 1800s for
about 500 years. This refutes the reading passage’s claim that a massive
volcanic eruption that caused a large amount of dust and ash prevented the
Earth from the solar radiation by causing the Little Ice Age.
Last but not least, the final point made by
lecturer is that it is doubtful that the increase in Earth reflectivity that caused
by the amount of glaciers and snow has affect the global cooling. In fact, the
cloud reflects most of the solar energy. If the temperature goes down, this
trend leads to decline water evaporation rate. As a result, the formation of
cloud is not occurred anymore, and then the reflectivity will be decreasing.
This contradicts the reading passage’s claim that the Earth’s great
reflectivity resulted in the Little Ice Age. |