Explained | What is ‘Climate Tipping Point’ and why is it trending

A ‘Climate Tipping Point’ is kind of a critical threshold when small changes lead to significant and often irreversible changes in the climate system if crossed. The sixth report of the United Nations Intergovernmental Panel on Climate Change (IPCC) defines a tipping point as a “critical threshold beyond which a system reorganizes, often abruptly and/or irreversibly”. The crossing of tipping point thresholds is likely to cause severe impacts on human society. 

The 2019 IPCC Special Report on the Ocean and Cryosphere in a Changing Climate defines a tipping point as: “A level of change in system properties beyond which a system reorganises, often in a non-linear manner, and does not return to the initial state even if the drivers of the change are abated. For the climate system, the term refers to a critical threshold at which global or regional climate changes from one stable state to another stable state.”

The History

Journalist and author Malcolm Gladwell’s book, ‘The Tipping Point’, introduced and popularised the term ‘tipping point’. In the book that was published in 2000, ‘tipping point’ has been described as ‘the moment of critical mass, the threshold, the boiling point’. 

Though the term has been used increasingly in scientific circles since then, it was first used by the IPCC in its fourth assessment report. Then it was thought ‘tipping points’ would only occur if global warming reached 5°C but recent IPCC assessments suggest that tipping points could be reached between 1°C and 2°C of warming.

The first major assessment of climate tipping points was published in 2008. The study found that nine parts of the climate system, named as ‘tipping elements’ could feature such tipping points. Most of these tipping elements had tipping points around 3-5°C.  

Since then, new ‘tipping points’ have been proposed and also questioned with the progress of climate science. The IPCC’s most recent report stated that risks involving climate tipping points start above 1°C, become moderate around 2°C, and high around 2.5-4°C. This points to the fact that climate tipping points are probably closer than earlier thought. 

Why is ‘Climate Tipping Point’ trending now?

This is happening because a major study published in the journal Science has recently found that as we cross the threshold of 1.1°C global warming, and even if we restrain warming to 1.5°C, we are already at risk of having triggered multiple ‘disastrous’ climate tipping points. 

The analysis has found that at the expected 1.5°C of heating four tipping points become ‘likely’ from ‘possible’. At that level of warming, ice sheets in Greenland and the West Antarctic may melt, coral reefs may die off and permafrost may abruptly thaw, the research found. At 1.5°C, five more tipping points become ‘possible’. The study shows evidence for 16 tipping points in total and the final six requiring global heating of at least 2°C. 

The location of climate tipping elements in the cryosphere (blue), biosphere (green), and ocean/atmosphere (orange), and global warming levels at which their tipping points will likely be triggered.

Pins are colored according to the central global warming threshold estimate being below 2°C, i.e., within the Paris Agreement range (light orange, circles); between 2 and 4°C, i.e., accessible with current policies (orange, diamonds); and 4°C and above (red, triangles).

Source: https://www.science.org/doi/10.1126/science.abn7950

The study, conducted by a team of international scientists led by David Armstrong McKay of Stockholm University, assessed more than 200 previous studies and presents an updated assessment of the most important climate tipping elements and their potential tipping points. It states that major changes in the climate system leading to huge environmental and social impacts are likely to occur at much lower temperatures than previously thought. 

Criticism

While the above-mentioned study has been widely read and discussed across the world at present, it also has been criticized for some aspects. Distinguished Climate Scientist, Michael E. Mann, in a statement published on his Twitter handle, said that the new study does not provide any substantial progress in determining precisely our closeness to the various tipping points. He also said that the authors are misinterpreting the paleoclimate evidence in at least one case involving the ice sheet collapse and sea level rise. He, however, agreed with the authors that exceeding 1.5°C warming comes with greatly increased risk and danger. 

Positive Tipping Points

A Positive Tipping Point takes place when the original system conditions have been transformed to achieve the desired vision. According to a 2018 study, ‘A positive tipping point occurs when the original conditions of a system of reference are substantially and irreversibly transformed in a way that matches or exceeds a particular desired (normative), better-off configuration or vision.’

A new initiative to launch ‘positive tipping points’ was started recently when experts met for the ‘Tipping Points From Climate Crisis to Positive Transformation‘ conference. The effort has been boosted by a £1 million grant from the Bezos Earth Fund. The team comprising of researchers and experts from the University of Exeter, Systemiq and the Systems Change Lab, will use the funding to “improve the assessment, forecasting and activation of positive tipping points” and produce a “state of tipping points” report.

“Positive tipping points in socio-economic systems must be found and triggered to radically accelerate the decarbonisation of the global economy, to limit the risk from highly damaging tipping points in the climate system,” said Professor Tim Lenton, Director of Exeter’s Global Systems Institute.

Some positive tipping points have already taken place in some sectors like the rapidly declining battery costs and policy support for electric vehicles, declining cost of wind and solar enabled by supportive policies, etc.