Proximity to Tipping Points

Proximity to tipping points

COP21 successfully negotiated a target to limit temperature rise to 1.5°C of warming in order to prevent 'dangerous climate change' limit of 2°C. Lenton and Schellnhuber (2007) attempted to relate IPCC climate change scenarios to multiple tipping elements. The figure shows policy relevant tipping elements which are elements which may exhibit tipping behaviour in the future for a 1.1-6.4°C warming. It is interesting to learn that the three major tipping points covered (Arctic, Amazon and THC) can possibly be triggered this century under three different warming trajectory (1-2°C, 3°C and >4°C). It is evident that even the widely used 2°C limit may not prevent the tipping of some elements and that societal tipping points (this post) - drastic technological and societal shift to a carbon-free economy is needed.

Source

While the number of 2°C is widely debated and deserves its own blog, it is essential that one looks beyond this number as the 2°C number is more of a political construct than a binary threshold/tipping point as defined in this blog. Obsessing over a symbolic 'end goal' for climate change not only detracts from public understanding but also fails to promote mitigation and fails to understand the reality by which anthropogenic activities are edging components of the earth system towards tipping behaviour (Knutti et.al. 2015). Although the few tipping points featured in detail in this blog mostly derived from increasing GHG emissions, they are not the only forcing to induce tipping behaviour (eg. aerosol emissions forcing re-organization of the Indian Monsoon and landscape fragmentation for regional terrestrial tipping points). Furthermore, it must be recognized that the tipping of one element may promote/induce rapid tipping behaviour of a different but positively connected element. Additionally, due to the inherent inertia and the non-linearity of different climate and biosphere systems as explored in this blog, it is probable that some tipping points may already have been surpassed but its impacts not yet fully realised. 

This feels like a good place to end my blogging journey. In the next post, I will reflect on major environmental news in 2016 and provide some reflections on the lessons learnt in the past 3 months.