Climate Change and Risk: Tipping Points

By Sally Campbell

“There are three stages to scientific discovery: first people deny it is true: then they deny it is important; finally they credit the wrong person.” Alexander von Humboldt.

Alexander von Humboldt (1769-1859) was a nature researcher and explorer, universal genius and cosmopolitan, scientist and patron. His lengthy Latin American journey from 1799 to 1804 was celebrated as the second scientific discovery of South America. Humboldt is considered be the ‘father’ of ecology, particularly for his work describing vegetation zones (geobotany) and climate using latitude and altitude. He also described in his lifetime future concepts such as human-caused climate change, geology and formation of stars. He was wise too, writing:
“The most dangerous worldviews are the worldviews of those who have never viewed the world.” Climate risks have been well known for decades.

So, what has changed in this 21st century?


“Our house is on fire” Greta Thunberg World Economic Forum Davos 2019

Research has ramped up and we now have a clear idea of the potential risks of climate change. Some of these risks are already being delivered on our doorstep..

What are the 5 tipping points in our climate crisis?
With thanks to: UN EHS

Tipping points are situations which once reached and underway there is no return possible. Out of those, one regional and three global climate elements are estimated to likely pass a tipping point if global warming reaches 1.5 °C (2.7 °F), namely Greenland ice sheet collapse, West Antarctic ice sheet collapse, tropical coral reef die off, and boreal permafrost abrupt thaw. The climate crisis has driven the world to the brink of multiple “disastrous” tipping points, according to a major study. It shows five dangerous tipping points may already have been passed due to the 1.1C of global heating caused by humanity to date.

These include:
1. the collapse of Greenland’s ice cap, eventually producing a huge sea level rise,
2. the collapse of a key current in the north Atlantic, disrupting rain upon which billions of people depend for food production,
3. and an abrupt melting of carbon-rich permafrost.


Copyright: nature


At 1.5C of heating, the minimum rise now expected, four of the five tipping points move from being possible to likely, the analysis has shown. Also at 1.5C, an additional five tipping points become possible, including changes to vast northern forests and the loss of almost all mountain glaciers.

In total, the researchers found evidence for 16 tipping points, with the final six requiring global heating of at least 2C to be triggered, according to the scientists’ estimations. The tipping points would take effect on timescales varying from a few years to centuries. “The Earth may have left a ‘safe’ climate state beyond 1C global warming,” the researchers concluded, with the whole of human civilisation having developed in temperatures below this level. Passing one tipping point is often likely to help trigger others, producing cascades. The complexity is the interaction of these.

Prof Johan Rockström, the Director of the Potsdam Institute for Climate Impact Research, who was part of the study team, said: “The world is heading towards 2-3C of global warming. This sets Earth on course to cross multiple dangerous tipping points that will be disastrous for people across the world. To maintain liveable conditions on Earth and enable stable societies, we must do everything possible to prevent crossing tipping points.”



Dr David Armstrong McKay at the University of Exeter, a lead author of the study, said: “The study really underpins why the Paris agreement goal of 1.5C is so important and must be fought for. Recent research has shown signs of destabilisation in the Amazon rainforest, the loss of which would have “profound” implications for the global climate and biodiversity, as well as the Greenland ice sheet and the Gulf Stream currents that scientists call the Atlantic meridional overturning circulation (Amoc). Our Atlantic climate on Arran is only present because of this oceanic condition.

A recent report by the Intergovernmental Panel on Climate Change said the risk of triggering climate tipping points becomes high with 2C of global heating. A further seven tipping points would have severe regional effects, including the die-off of tropical coral reefs  and changes to the west African monsoon. Other potential tipping points still being studied include the loss of ocean oxygen and major shifts in the Indian summer monsoon.

Look at the world around you.
It may seem like an immovable place. It is not.
With the slightest push – in just the right place – it can be tipped.
Malcolm Gladwell:
The Tipping Point: How Little Things can make a Big Difference. 2000

We can be the agents of change, working together in communities. Now is the time and opportunity.

Gladwell, Malcolm (2002) The Tipping Point: How little things can make a Big Difference. Little, Brown Book Group.
Rockström, Johan and Gaffney, Owen (2021) Breaking Boundaries: The Science of our Planet Dorling Kindersley
UNU EHS The 2023 Interconnected Disaster Risks report analyses six interconnected risk tipping points, representing immediate and increasing risks across the world.

Sally Campbell
October 2023

Featured image accessed at