100 more pages of text isn't the only difference in this new edition of Bob Jones' Earth Science. It still includes both earth and space science, but the flow is much more logical and smooth, and the bulky P.I.L.R. sections at the back of both volumes of the 3rd edition are gone. Students begin with a defense of doing science as Christians, then jump right into a fairly strenuous introduction to geology, environmentalism, oceanography, the atmosphere, climate, cosmology, the solar system, etc.
The text has been significantly updated and streamlined, and there are a lot more illustrations, all in full color. Each topic is presented from a rigorously Christian perspective, showing kids not only how science works, but how to think about it as children of God. The authors are decidedly creationists, and evolutionary theory is repeatedly debunked. The fact that this 4th edition student text comes in a single volume (rather than two, as with the 3rd edition), makes it easier to carry around and use; the added information and illustrations make it a better book.