By Laura Pereira, University of the Witwatersrand
(The Conversation) – New research has found that the world has reached the first of many Earth system tipping points. These will cause catastrophic harm unless humanity takes urgent action.
A tipping point is a moment in the Earth’s climate system where even small changes can lead to significant, often irreversible consequences. Some of the most well known global tipping points are melting ice sheets at the north and south poles, the dieback of the Amazon rainforest and the collapse of vital ocean currents. If these happen, food systems could break down and sea levels would rise rapidly.
Tipping points also speed up global warming, making more climate disasters likely.
I’m a sustainability scientist, and I was part of a large, global team who recently updated the 2023 Global Tipping Points report. This report identifies “negative” tipping points that will likely trigger devastation in the world, and the potential for “positive” tipping points – where a desirable change becomes widespread (such as finance flowing towards nature-supporting activities).
In our second Global Tipping Points Report, we explain that some damaging Earth system tipping points are already being crossed. Others could soon follow, with potentially catastrophic impacts on societies and nature globally.
It’s important to note that negative climate tipping points cannot be reversed.
This means that if the world underestimates how certain events could trigger a climate tipping point, we might run out of time to act before the damage becomes irreversible or too severe to adapt to.
Governance has to change to address this new reality. Small, step-by-step changes are not going to be enough for the world to avoid the worst impacts of global warming. Climate action must accelerate radically to eliminate greenhouse gas emissions that stress ecosystems, and to regenerate nature before it is too late.
One tipping point triggers another
Climate tipping point risks are interconnected. Most of the interactions between them are destabilising. This means that tipping one system over into disaster makes tipping another more likely. The negative impacts would cascade through the ecological and social systems we depend upon, creating damage that keeps mounting up.
Global temperatures in both the atmosphere and oceans have recently spiked. Oceans are absorbing 90% of extra heat from the earth that isn’t absorbed by plants. This is a sign that Earth’s climate is becoming increasingly unstable. While these spikes are not tipping points themselves, they can trigger them.
For example, if the Atlantic Meridional Overturning Circulation (AMOC) (system of ocean currents) collapses, then west Africa will likely experience more frequent and severe droughts. This is because these currents move warm surface water to the north and cold deep water to the south in the Atlantic, moving heat around and regulating global climate. Without it, the west African monsoon will be disrupted and this will reduce rainfall and cause hotter, drier conditions.
There is growing evidence from observations and modelling that the AMOC could be at risk of either entering a tipping point or collapsing.
Another example is Africa’s coral reefs. Over 80% of the world’s coral reefs, including reefs in Kenya, Senegal, Cape Verde, Tanzania, Mozambique and Madagascar, were hit by the worst global coral bleaching event on record between 2023 and 2025. Coral bleaching is where coral becomes stressed when the water heats up too much. Prolonged bleaching can lead to widespread coral death.
As coral protects the coast from wave damage and provides food and income from tourism, coral death in African waters would be a huge problem.
Taking action
All major Earth systems are becoming more likely to reach dangerous tipping points because of global warming. However, some are also being pushed closer to collapse by local human activities, such as deforestation or overfishing.
This means that there is a chance to act to stop the damage – for example, by reducing deforestation of the Amazon, or reducing overfishing of coral reefs.
The world must act right now. The window to prevent serious damage is closing fast. Countries have committed to reducing greenhouse gases but not enough to stop global warming from shooting more than 2°C above pre-industrial times by 2100.
Political instability, conflicts and attacks on climate science are making coordinated action harder.
The risks of delaying are too great. The world’s governments need to radically speed up climate mitigation (steps to reduce emissions to protect the planet and people from climate change).
Positive tipping points are examples of these actions that could lead to exponential change. Our report identified that these already exist. For example:
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solar photovoltaic panels are decreasing in price so that more people can switch to solar energy
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battery storage systems that store power are becoming more affordable and can be recycled
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judgements against fossil fuel companies in climate lawsuits.
These positive tipping points are starting to interact and reinforce one another.
What needs to happen next
The International Court of Justice recently ruled that world leaders must take immediate action, on a level that hasn’t been seen before, to prevent climate change.
When they do this, justice needs to be at the centre to make sure that preventing climate change does not have unintended negative consequences. For example, mining rare earth metals to meet growing demand for battery storage can unfairly displace communities living on mineral-rich lands.
Another example is the race to mine the seabed for minerals to make renewable energy components. This risks damaging or destroying entire, under-explored ecosystems and the ecosystem services they provide.
New harms must not be caused while trying to stop climate change.
Laura Pereira, Associate professor, Global Change Institute, University of the Witwatersrand
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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