Sea urchin, Costa Rica | Photo: Ines Stuhldreier

05/12/2023 | The world has reached a pivotal moment as threats from Earth system tipping points – and progress towards positive tipping points – accelerate, a new report shows. The Global Tipping Points Report – the most comprehensive assessment of tipping points ever conducted – says humanity is currently on a disastrous trajectory. The Global Tipping Points Report is now being presented at the United Nations Climate Change Conference in Dubai (COP28).

The report was produced by an international team of more than 200 researchers, coordinated by the University of Exeter, in partnership with Bezos Earth Fund. On the part of the ZMT, postdoctoral researcher Dr Giovanni Romagnoni contributed to this review with his expertise about potential tipping points in coastal upwelling systems and in pelagic ecosystems.

In particular, he focused on the kelp-sea urchin systems. “These systems may be prone to irreversible tipping points that are in many areas already critically affecting ecological dynamics in temperate and subtropical coastal rocky systems as a result of, among other stressors, environmental change” Romagnoni says.

Kelp, i.e. macroalgae, and sea urchins tend to show strong coupled dynamics. Sea urchins are among the main grazer of kelp and can lead kelp forests to complete disappearance in a short time frame, when their population increases uncontrolled. This can happen for example when their predators decline. Temperature changes influence the distribution and productivity of kelp, of sea urchins, and of their predators.

The speed of fossil fuel phase out and growth of zero-carbon solutions will now determine the future of billions of people. The report says current global governance is inadequate for the scale of the challenge and makes six key recommendations to change course fast, including coordinated action to trigger positive tipping points. A tipping point occurs when a small change sparks an often rapid and irreversible transformation, and the effects can be positive or negative.

Based on an assessment of 26 negative Earth system tipping points, the report concludes “business as usual” is no longer possible – with rapid changes to nature and societies already happening, and more coming. With global warming now on course to breach 1.5° C, at least five Earth system tipping points are likely to be triggered – including the collapse of major ice sheets and widespread mortality of warm-water coral reefs.

As Earth system tipping points multiply, there is a risk of catastrophic, global-scale loss of capacity to grow staple crops. Without urgent action to halt the climate and ecological crisis, societies will be overwhelmed as the natural world comes apart. Alternatively, emergency global action – accelerated by leaders meeting now at COP28 – can harness positive tipping points and steer us towards a thriving, sustainable future.

The report lays out a blueprint for doing this, and says bold, coordinated policies could trigger positive tipping points across multiple sectors including energy, transport, and food. A cascade of positive tipping points would save millions of lives, billions of people from hardship, trillions of dollars in climate-related damage, and begin restoring the natural world upon which we all depend.

The report includes six key recommendations:

  • Phase out fossil fuels and land-use emissions now, stopping them well before 2050.
  • Strengthen adaptation and “loss and damage” governance, recognising inequality between and within nations.
  • Include tipping points in the Global Stocktake (the world’s climate “inventory”) and Nationally Determined Contributions (each country’s efforts to tackle climate change)
  • Coordinate policy efforts to trigger positive tipping points.
  • Convene an urgent global summit on tipping points.
  • Deepen knowledge of tipping points. The research team supports calls for an IPCC Special Report on tipping points.

To the report: