Introduction to the Focus Issue: Nonautonomous dynamics in the climate sciences

This Focus Issue is, along with the one on Nonautonomous dynamical systems: Theory, methods, and applications, part of the Double Focus Issue on Nonautonomous dynamical systems in the sciences. We refer to the two twin Focus Issues as NDS-G and NDS-C, for short, where "G" stands for General and "C" for Climate. A key area of inquiry for understanding climate behavior in this century is the impact of anthropogenic and natural forcing on a system that is highly nonlinear and exhibits both chaotic and random aspects. The theory of NDSs is the perfect framework for exploring this impact. The 16 papers in this issue address several questions within this broad area: (i) various types of tipping that have arisen in the system's history or may occur in its future; (ii) the effects that one component of the climate system might have on another one; and (iii) how we may better learn from observations and model simulations about all that is going on within the system.