It is very hard to know which argument to take more seriously. Both arguments use scientific data to make their points. When experts use the same data to come to different conclusions, it is very hard to know which experts to believe. In the end, it almost comes down to an issue of faith. In other words, when two experts use the same data to tell different stories, whose story do you have more faith in? My own view is that I have more faith in Diamond’s argument.
In the chapter on Easter Island in Questioning Collapse, there are two main causes cited for the plight of the people of Easter Island. One is rats and the other is Europeans. The chapter argues that rats were the main cause of deforestation. It argues that the rats ate the palm nuts and seedlings and thus deforested the island. It then goes on to argue that the real decline in the population was caused by Europeans, though it does not mention how they were responsible for the decline.
Diamond, by contrast, argues that the people of Easter Island themselves were responsible for the deforestation. He argues that they cut down too many trees in order to cultivate the island, in order to make fires, and in order to transport their huge statues. My own view is that Diamond is closer to the truth. He presents convincing evidence that the deforestation had already happened before European contact. He makes a convincing argument for why the people of Easter Island would have cut down so many trees. Above all, he sees the people of Easter Island as similar to modern people. In other words, he believes that they were capable of abusing their environment. People like McAnany seem to believe that it would have been impossible for the people of Easter Island to abuse their environment. This is hard for me to believe. People all over the world have abused their environments. There is no reason for me to believe that the people of Easter Island could not have done so.
Thus, I tend to believe Diamond largely because I believe that people at all times and places have been willing to overuse their environment.