Earth's climate as a problem in physics

Among the outstanding problems that physics has to face, surely, the understanding of the climate’s behavior can be considered one of the most challenging. All the fundamental forces seem to operate at the lowest order. However, it appears that they operate with a large degree of randomness wherein a systematic (deterministic) behavior is floating in this sea of uncertainty. It is hard, in fact, to exclude that observations just describe the outcome of an erratic dynamics, while it is equally hard to rule out that certain effects may have well-established causes.