Pivotal moment for humanity as tipping point threats and opportunities accelerate

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. This is shown by the Global Tipping Points Report, an comprehensive assessment of tipping points by over 200 researchers, including scientist from Radboud University.

The Global Tipping Points Report is the biggest assessment of tipping points ever conducted. It says humanity is currently on a disastrous trajectory. 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.

Collapse of ice sheets

With global warming now on course to breach 1.5C, 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. 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.

Positive tipping points

Dr Steve Smith, at the University of Exeter, said: ’Just as with Earth system tipping points, positive tipping points can combine to reinforce and accelerate each other. For example, as we cross the tipping point that sees electric vehicles become the dominant form of road transport , battery technology continues to get better and cheaper. This could trigger another positive tipping point in the use of batteries for storing renewable energy, reinforcing another in the use of heat pumps in our homes, and so on.’

Sarian Kosten, ecologist at Radboud University, focused for this report on shallow lakes and their methane emission. ’I looked at which environment variables can cause tipping points in shallow lakes and how this affects the climate. A well known example is that with a certain amount of fertilizers like phosphate, a green algae soup will appear in lakes. Because of this soup, water plants below the surface won’t receive any light and will vanish. Not only is that unfavorable for water quality and biodiversity, but it also increases the methane emission from the lake.’

Sibel Eker, researcher at Radboud University, adds: ’One of the biggest promises of this positive tipping concept is the cross-system interactions, such as an intervention in the energy system can have positive impacts on transport, agriculture, or social norms and values. In the chapter I led, we analyzed such cascading impacts and opportunities positive tipping can create. We concluded that public authorities and non-governmental agents can both play a role in triggering cascades through super-leverage points.’

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.

Parts of the Global Tipping Points Report will be published in a special issue of the journal Earth System Dynamics. The report is publicly available at: https://global-tipping-p­oints.org/