Environmental and ecological problems are currently front burner national issues. This DVD presents a lecture by and an interview with Simon Levin, one of the leaders in the application of mathematics in these areas. Drawing on a range of examples, Levin shows that the fundamental problem is relating processes that operate on very different scales of space and time--for example, the problem of global change centers on understanding how large-scale changes in temperature and greenhouse gases translate into effects on individual leaves and plants. Levin discusses how mathematical methods can be used to approach such problems. In the interview segment of the DVD, he provides further background on some of the topics in his lecture and discusses how he became interested in this field of research. Because a mathematical background only at the level of calculus is assumed, this DVD will appeal to a general scientific audience interested in environmental issues, as well as to students and researchers in the mathematical sciences.