While Janzen was planning his descriptive, observational study with wild populations of painted turtles, he wanted to find out how much temperatures were predicted to rise over the next 100 years. He is not a climatologist, but fortunately, scientists can rely on work done by other scientists. When scientists look for scientific information, they use primary scientific literature. Primary literature often takes the form of a journal that is published multiple times a year. There are hundreds of journals devoted to different fields of scientific research. The journals include papers that describe in detail the methods, results, and conclusions from scientific studies. A hallmark of primary literature is that the papers are reviewed by other scientists before they are published. This so-called peer review helps ensure accuracy and reliability. As a student, you might not go to primary literature as a first step. You might seek out information in popular literature aimed at nonscientists. When considering what popular sources to use, it is important to evaluate their reliability. For instance, consider the credentials of the author, if the source has an agenda or bias, if primary sources are cited, and if the information is consistent with what you find in other reliable sources. Suppose you found the following sources for Janzen to use as references for the predicted rise in global temperature. Indicate if each source is an example of primary literature, and then decide if each source is reliable. If you are uncertain about a source, look it up online.