Prof. Macdonald is a great instructor. His Env. Change class was super interesting, and I really learned valuable info regarding the history of the natural processes our Earth went/goes through. His lectures are clear and he's a humorous and entertaining guy. That's not to say his class was "easy". The cool thing, though, is that his exams accurately reflect his lectures. If you take good notes and study them like crazy, you will do well on the exams. I did so and managed an A+. A tip for doing well: write down AS MUCH INFO as you can on each exam question, as he (his readers) grades for thoroughness. Definitely one of my favorite classes and professors that I've had at UCLA.