Multiscale effects are challenging issues in materials science, but ours is not the only domain in which they are of current interest. Global climate change obviously operates at the largest length-scales available on a planet the size of Earth (or even Saturn, where the famous red spot is shrinking) but it is a product of effects that operate on the scales of individual machines, buildings, cities, tidal systems, and the molecular reactions within each of these. Understanding all of these is a daunting task.