'Little things can make a big difference'

Welcome back to my blog! In this post, I will endeavour to discuss the emergence of 'tipping point' as a concept in mainstream scientific communication and public discourse. 

Emergence of Tipping Points

The basic principle behind climatic tipping points can be attributed to the journalist/sociologist Malcolm Gladwell. In the 2000 book 'The Tipping Point', Gladwell theorized the presence of sudden, dramatic shifts in sociological/behavioural phenomena under the influence of rapidly spreading ideas and messages, popularizing the notion that 'little things can make a big difference'. This was subsequently quoted directly in Lenton et.al. (2008), one of the first comprehensive review of climatic tipping points. The widespread emergence of tipping points in mainstream scientific literature and public discourse on climate change can be traced back to a 2005 American Geophysical Union address by world renowned climate scientist James Hansen in which climate tipping points were defined as irreversible critical points (Russil and Nyssa 2009). Scientific research on global climate change prior to the mainstreaming of tipping points rarely appreciate the full range of outcomes. 'Climate alarmism' were often used to describe the very few assessments which considered events defined as 'low probability' but with extreme consequences (Schneider 2004). Since Hansen's 2005 address, tipping points have since been a major part of climate research and scientific communication. It was included in the latest IPCC report with scientists concluding with medium confidence that a continued rise in temperature will increase the risk of crossing climatic thresholds and thereby triggering abrupt and irreversible changes (IPCC 2014).

Defining Tipping Points

Theories and modelled results previously described as being too uncertain and alarmists are now considered mainstream and scientific. A plethora of different terms with slightly different or overlapping meanings had emerged since in mainstream scientific literature. These terms may include 'dangerous climate change', 'state shift', 'regime shift', 'abrupt change' and 'threshold' and their uses are often rather confusing and chaotic (Lenton 2013). All of which recognize the enormity of anthropogenic influence but may differ in terms of irreversible conditions, hysteresis and abruptness. While I realize that descending into a semantic debate about the definition of tipping points detracts from the urgency of the situation, it is definitely advantageous to identify some key differences between the terms from which I will adopt a general definition which future posts will be based upon. Listed below are definitions of the most used terms with some overlapping elements:

• Tipping Element - policy-relevant, subsystems that can be tipped into qualitatively different states by small, but significant perturbations (Lenton et.al. 2008) 
• Threshold - critical point that once surpassed will trigger some kind of non-linear change

• Regime Shift  - (Ecology) large, long-lasting re-organization of system structure to alternative stable state either through abrupt shock or gradual erosion of system strength by internal feedbacks or external influence (Biggs et.al. 2009). May be abrupt, smooth or discontinuous. (Can occur in social systems as well)

• Hysteresis - Irreversible regime shift across multiple stable states where the ceasing of perturbation does not lead to system returning to its original state (Barnosky et.al. 2012)

• Bifurcation - A change in equilibria possibly resulting in the transition to a new set of stable conditions which will inevitably lead to irreversibility (Barnosky et.al. 2012)

To avoid confusion, I will be referring to 'tipping point' as a term meaning potentially abrupt reversible (non-bifurcation) or irreversible change across social and environmental systems (across ecological, socio-economic, climatic). This definition, though simplistic, allows me to comment on elements with different tipping behaviour, going beyond some who may narrowly define tipping points (Barnosky et.al. 2012; Lenton and Williams 2013).