Holocene stability: climate attractor, or lucky break?

Palaeorecords indicate that global temperatures have been relatively stable for the past ~10,000 years of the Holocene epoch, in contrast to cooling trends during previous interglacials and multiple abrupt shifts during past glacials. Hypotheses for this seeming stability range from early anthropogenic emissions to orbital factors or the timing of carbon cycle feedbacks. An alternative suggestion grounded in dynamical systems theory is that Holocene stability reflects the Earth system residing in a climate ‘attractor’, with strong negative feedbacks acting to stabilise the climate’s state, and glacial/interglacial cycling representing either a limit cycle or tipping between interglacial and glacial attractors. This in turn has led to the more recent hypothesis that human actions are eroding the resilience of the Earth system’s current state, and at some level could be sufficient to tip the whole Earth system into a warmer “Hothouse Earth” attractor. However, despite multiple hypotheses for Holocene stability, that the Earth system is close to the edge of a dynamical attractor is often assumed rather than demonstrated. Here, I review the basis for the Holocene climate attractor hypothesis in the literature, and assess to what extent there is sufficient evidence to support it versus other possibilities. I then outline what additional evidence might be needed, and consider how Earth system states and resilience can be alternatively conceptualised.