  Tipping points associated with bifurcations (B-tipping) or induced by noise
(N-tipping) are recognized mechanisms that may potentially lead to sudden
climate change. We focus here a novel class of tipping points, where a
sufficiently rapid change to an input or parameter of a system may cause the
system to "tip" or move away from a branch of attractors. Such rate-dependent
tipping, or R-tipping, need not be associated with either bifurcations or
noise. We present an example of all three types of tipping in a simple global
energy balance model of the climate system, illustrating the possibility of
dangerous rates of change even in the absence of noise and of bifurcations in
the underlying quasi-static system.
