In the listening material, the professor challenged the three traditional theories which are mentioned in the reading passage. He gave the following modern viewpoint propod by the scientists.
First, in the considering about the factor that disruption of ocean currents contributing to the Ice Age, there is something not accurate. Though the cold fresh water melt from the glaciers will cau the breakdown of t he Gulf Stream, it will only relate to the roaring decline of temperature in Europe and North America, but can not make n of the global change into ice age including southern area such as New Zealand.
Second, while the reading passsage is concerned that the volcano eruption is the invitation to the ice age, the listening material pointed out that the dimension of the eruption of volcanos maybe was not huge enough to account for the form of ice age becau with large range of volcano eruption, there would usually be some awkward transformations in weather and landscape condition conquently. However, there are not specific reports about it such as the view of dramatically colourful sunt or the grey clouds caud by the volcano ash before or during tho ice ages.
Third, the theory about the absorption of carbon dioxide by the trees causing Earth cooler was challenged. The professor thought that despite the fact that more trees would take in more green hou gas, it would not last for a long term becau the growing number of oxide which would increa humans population also make the trees cut down and grow back to the previous quantity to reach a balance.
