Earth System Tipping Points: What do they mean for climate action?

Earth is a dynamic system in which oceans, ice, atmosphere, land and life continuously interact and change. Together, these form the “Earth system”, which has maintained conditions suitable for life for billions of years.

However, human-driven climate change over the last century has started to disrupt parts of the Earth System, especially in vulnerable areas recognised by scientists as ‘tipping points’. The Intergovernmental Panel on Climate Change defines these as “critical thresholds beyond which a system will reorganise, often abruptly and/or irreversibly”.

Current studies recognise around 16 major tipping points  across the globe which have the possibility of ‘tipping’ at anywhere between 1° C to 5° C of warming. These are made up of cryosphere, biosphere and ocean-circulation tipping points. For example, ‘Greenland Ice Sheet collapse’ represents a cryosphere threshold beyond which ice loss would become irreversible.

Map showing the 16 tipping points with an estimation of their threshold. Credit: David Armstrong McKay, 2022

Tipping points themselves are part of a geological and meteorological process, but they will have huge impacts on society, economy and global governance in this century. Taking the example of ice sheet loss, the major impact will be rising sea levels. Antarctic ice sheet loss leading to sea level rise would expose 480 million people to annual coastal flooding events, with cascading impacts on infrastructure, livelihoods, health and migration. Tipping points will amplify existing vulnerabilities and create new systemic challenges – impacts will be unknown, compounding, and cascading.

AMOC collapse

One of the most studied tipping points is the ‘Atlantic Meridional Overturning Circulation’, AMOC. The AMOC functions like a large-scale ocean conveyor belt; warm water from the tropics travels north on the surface of the ocean. When it gets to the Arctic Sea it rapidly cools and then travels back on a deep ocean current. This huge overturning of the ocean is what drives heat and climate patterns in the Atlantic, including Eastern America and Canada and large parts of Europe.

Credit: NASA JPL. A diagram of AMOC circulation as part of the global Ocean flows; box added.

Climate change is weakening this system. Increased freshwater from melting ice (particularly from Greenland) reduces the salinity and density of ocean water, making it harder for it to sink. As a result, scientists have observed a significant decline in AMOC strength since the mid-20th century. AMOC collapse – which is now expected to occur anywhere between 2037 and 2109. – will radically change the world’s weather patterns.

Compounding effects

In an AMOC collapse scenario, countries like England and Iceland will see dramatic cooling and drying because no warm weather systems will reach Europe. On the other hand, heat from the South will be trapped there and cause regional warming. Agricultural productivity could decline sharply, with climate models suggesting that major crop yields would fail, and energy demands would skyrocket in a colder climate.

In a recent report by the Nordic Council, they use a ‘storyline’ approach to show what AMOC collapse could look like in Iceland in 2087; these are fictionalised accounts created through future modelling and scenarios.

“The coastal fisheries were first to collapse as spawning failed”

“Domestic food insecurity is projected to reach 62% by winter 2088”

“With the North-West and North-East Passages impassable, global shipping routes are collapsing”

These examples help picture how tipping points trigger cascading impacts across systems including food, energy and trade.

What does this mean for climate governance?

As shown in the example of AMOC collapse, tipping points introduce even more uncertainty into climate governance. They are what’s known as ‘high impact, low likelihood’ events, but their likelihood is now dangerously increasing. They transform climate change from a gradual transition challenge into a sudden systemic shock which requires a new model of governance.  Governance of tipping points should prioritise the prevention and mitigation of harm at all stages: prior to, during, and after a tipping event.

As highlighted in a recent report by the Nordic Council of Ministers, there is an urgent need to move from risk identification to actionable adaptation strategies that account for abrupt disruption. In line with the Global Tipping Point Report, this includes strengthening cross-border coordination, embedding resilience into economic planning, and planning responses before crises occur. By building resilience in an economy or in a community, societies can be more sustainable, equitable, and prosperous, with the added benefit of being prepared for tipping points.

No-regrets solutions

Due to the uncertainty about when tipping points will occur, it is important to focus on “no-regrets” actions – which deliver social or economic benefits but also build future resilience. This will build robust and flexible systems that can withstand disruption.

The transition to renewable energy is a clear example. Renewable energy has already proved to be cheaper and cleaner to produce, as well as mitigating against geopolitical shock and fuel dependence. According to the UN, the world has reached a "positive tipping point" where renewable energy is now cheaper and more widespread than fossil fuels, with 92.5% of new electricity capacity in 2024 coming from green sources. As well as these social and political benefits, in the event of the AMOC tipping point, we will be better prepared for the spike in heating demands and disruptions to world trade.

What to do today?

Tipping points will have cascading implications for supply chains, economic markets and communities. This shows the cost of delayed action and the necessity for change, which must be collaborative and collective.

Associations and membership organisations have an important role in climate leadership and, with CAFA’s help, can offer guidance and best-practice for climate action. Key priorities include integrating tipping point risks into strategic planning, supporting members in building resilience through energy transition and fostering collaboration across sectors. Implementing no-regrets actions can strengthen businesses today while preparing industries for shocks in the future. In doing so, associations can play a critical role in driving both climate action and resilience.

If you are a membership organisation keen to connect with peers who have started their journey to support their members on sustainability, join the CAFA Collective today.