TPO 27

Recently, there has been a ton of debate about what caused the Little Ice Age. More specifically, regarding the passage, the author puts forth the idea that some environmental phenomena and changes in the human population prompt the Little Ice Age period. In the listening, the lecturer is quick to point out there are some serious flaws in the writer's claims. In fact, the professor believes that the reasons mentioned by the writer are out of date and not convincing, and addresses the trouble with each point made in the reading text.

First of all, the writer states that some disruptions of ocean currents may have an effect on cooling. In fact, there was a period of unusually warm weather during which glaciers melted. Thus, it released a large amount of cold freshwater into the Gulf Stream. Some professionals in the field stand in firm opposition to this claim. The speaker, for example, believes that changes in ocean currents would cause the cooling only in Europe and North America, but as the scientists suggest, it happened everywhere, for example, in Africa and New Zealand. Therefore, this event cannot be a cause for the changes in climate.

One group of scholars, represented by the writer, think that volcanic eruptions could have caused the Little Ice Age. They posit that dark clouds of dust and sulfur sent by the eruptions blocked some sunlight from reaching Earth's surface. Not all experts in the field believe this is accurate. Again, the professor addresses this point when he states that there should have been some records of visual effects such as colorful sunset or brown snows if this phenomenon has happened, and hence the people should have some reports of these events. But as there is no evidence regarding this matter, the clouds probably were not strong enough to cover significant parts of the Earth's surface.

Finally, the writer wraps this argument by proposing that there was a decline in human population, and it resulted in forests growing on agricultural lands, and therefore there were fewer greenhouse gases which kept the Earth warm. Not surprisingly, the professor takes issue with this claim by contending that there was not enough time for such chains of events. The human population grew fast after the decline, and forests were cut down quickly again by humans.

To sum up, the writer and the lecturer hold conflicting views about what caused the Little Ice Age.