The Global Tipping Points Report, launched at COP28 on 6 December 2023, is an authoritative assessment of the risks and opportunities of both negative and positive tipping points in the Earth system and society.

Global Tipping Points is led by the University of Exeter’s Global Systems Institute with the support of more than 200 researchers from over 90 organisations in 26 countries. The 21st century has already witnessed extraordinary, abrupt and potentially irreversible changes in the world around us. With global warming now at around 1.2°C above the pre-industrial level, massive coral reef die-off events are occurring, the Amazon rainforest is suffering droughts, large regions of permafrost are thawing, and part of the West Antarctic Ice Sheet may be irreversibly retreating, to name but a few of the tumultuous changes happening in the Earth system. In the last decade, climate impacts have escalated, harming the economy and resulting in  insurance being withdrawn from some of the most vulnerable communities. The global financial crisis of 2007-2008 and ensuing Great Recession have shown us how fragile the economy can be, and the COVID-19 pandemic gave us all a profound lesson in abrupt, cascading change. At the same time, we have started to see evidence of accelerating social and technological change towards sustainability, including numerous political declarations of a ‘climate emergency’ and exponential growth of renewable energy deployment.

All of this experience challenges a worldview that many of us were brought up with – to see the world like a machine. The world is not behaving in a linear fashion. Instead, our expectations of smooth, predictable and reversible changes are being confronted with a reality of abrupt, unexpected and irreversible ones. We wrote this report during 2023 against a backdrop of unprecedented climate extremes, including severe heat waves across much of Asia, massive loss of Antarctic seaice, and Canadian forest fires way off the scale of even recent experience. The pace and scale of these events has attracted use of the term ‘tipping points’ which describes the phenomenon that occurs when a small change makes a big difference to a system. Tipping points in the Earth system are arguably the biggest risk we face in a changing world, because they can lead to profound damages that are abrupt or irreversible – or both. The level of global warming that could trigger known climate tipping points is uncertain; there is little assessment of tipping point impacts and even less consideration of who or what is most vulnerable to those impacts. Yet we know enough to argue that any credible climate change risk assessment must consider the risks from climate tipping points – as they could profoundly affect the economy and societies.

Furthermore, while climate tipping points are often portrayed as ‘high-impact, low-likelihood events’, some are rapidly becoming ‘high-impact, high-likelihood events’. The risks from anthropogenically triggered Earth system tipping points, and our perception of them, may in turn influence tipping points in human systems. These ‘social tipping points’ can take many forms – from the escalation of wars to the sudden uptake of new technologies. The global financial crisis and the COVID-19 pandemic demonstrated how undesirable impacts can cascade through our networked world. But this potential also exists for desirable impacts. The same feedback principles underlie both undesirable tipping points in the Earth system and those in human systems, both desirable and undesirable. As experience starts to show how risks can cascade between the different realms of climate, ecology and human society, there is a growing sense that we are in a ‘polycrisis’. But experience has barely scratched the surface of what could occur as the impacts of global change – especially climate change – accelerate and accumulate. Hence, there is an urgent need to assess how Earth system tipping points can impact human systems, especially whether and how they could trigger undesirable social tipping points. This is essential information to enable mitigation of the worst impacts and to build resilience to impacts that cannot be avoided.

Growing recognition and knowledge of tipping point risks in turn begs the question of how best to govern those risks. Can our current institutions and processes deal with tipping point risks? Or do the unusual qualities of tipping points (abruptness, irreversibility, unpredictability, and having large but unevenly distributed impacts) demand new governance approaches? Against this backdrop of profound risks, the opportunities for creating and enabling ‘positive tipping points’ to accelerate action to tackle climate change, biodiversity loss and other sustainability challenges are just starting to be widely recognised. They may offer the most credible way of achieving the acceleration of action that is required – by leveraging strongly reinforcing feedback processes that are self-propelling. When presented with such complexity and tumultuous change, we cannot continue  looking at the world in an outdated way. We need an effective and comprehensive risk assessment of ‘negative’ tipping points; we need an opportunity analysis of realised and potential ‘positive’ tipping points; and we need to consider how to navigate both, in a just way, in the face of uncertainty. The experience of the author team tells us many people are hungry for this knowledge.

Wetenschappers waarschuwen in Dubai voor ‘domino-effecten’ klimaatverandering