The 16 climate change tipping elements and their tipping points

What are tipping elements and tipping points in climate change??

Tipping elements are critical climate systems that are important for our Earth’s climate. If these tipping elements change, the climate on our entire planet changes.

Tipping elements may pass a tipping point. Tipping points refer to critical thresholds in the climate system. If a tipping element crosses this threshold, a seemingly small change can lead to a sudden and irreversible change in the system.

Examples of tipping elements are the Amazon rainforest or the Arctic ice. If the temperature on Earth rises, these systems will be severely affected when a certain temperature is reached - the tipping point.

We use the word ‘tipping’ because these changes cannot be reversed once they occur. They have tipped over.

Imagine a pencil, balancing on the edge of a table. You keep pushing it forward. For a while, nothing happens. At some point, the pencil falls down. You cannot simply undo this process. The pencil lies on the floor. This is also the way tipping elements work.

Tipping elements can start to falter when our Earth warms by only a few degrees. We will no longer be able to reverse these changes. That is why we only have a limited amount of time to prevent this from happening.

What are the climate tipping elements?

Let us use the Amazon rainforest as an example of tipping elements. If the Amazon rainforest dies, a chain of events is set in motion. This could happen if we warm our planet by over 2 degrees Celsius.

According to the Potsdam Institute for Climate Impact Research (PIK), the rainforest could reach its tipping point in the next 100 years due to global warming. This process would be sped up, however, if we continue to cut down the rainforest. Then, the process would take considerably less than 100 years. It is possible that the next generation of people will experience life on a planet without rainforest.

Tipping elements are complex. Every single one can trigger a large series of other events. And these in turn will trigger chain reactions. If the Amazon rainforest dies, it is not just the forest that is gone.

Regional weather may change. Less CO₂ would be absorbed worldwide, leading to more global warming. In this world, all climate phenomena are interconnected.

Thomas Stocker, a Swiss climate scientist says:

There are various mechanisms behind each tipping element that may cause it to cross its tipping point. What these mechanisms have in common is that a change in their state could have consequences for the entire planet.

What are the consequences of tipping elements crossing their tipping point?

The PIK has identified 16 of these tipping elements, of which the rainforest is one. It concerns 9 global tipping elements and another 7 regional tipping elements.

Learn more about the 9 global tipping elements and their tipping points:

1. Greenland Ice Sheet

The entire island of Greenland is covered by a layer of ice that measures 3 kilometres thick in some places. As a result of global warming, the ice is now melting into the sea.

Should this tipping element cross its tipping point, Greenland would likely be ice-free for the next 10,000 years. Globally, sea levels would rise by about 7 metres.

This tipping point could be triggered by as little as 1.5 degrees Celsius of global warming. Currently, we are estimated to be at 1.1 degrees of global warming.

2. Arctic Winter Sea Ice

The Arctic ocean is covered by sea ice throughout the year. The extent of the ice cover depends on the season.

Should the Arctic ocean become completely ice-free, the high northern latitudes will warm up twice as fast as the global average.

The Arctic tipping point is estimated to fall between 4.5 and 8.7 degrees Celsius.

3. Boreal Permafrost

The Arctic permafrost or permafrost soils have been frozen for centuries or even millenia. They are located in Siberia and North America.

If they were to thaw, they could release huge amounts of the greenhouse gases carbon dioxide and methane. Several hundred billion tons of carbon are estimated to be stored in these so-called Yedoma soils at depths of more than three metres.

This tipping point could be activated at 4 degrees Celsius.

4. West Antarctic Ice Sheet

The West Antarctic ice sheet lies below sea level on the continental bedrock. At its deepest point, it reaches a depth of 2.5 kilometres below sea level.

At a 1.5 degree temperature increase, this ice could melt and cause the sea level to rise by 3 metres worldwide.

5. East Antarctic Ice Sheet

The East Antarctic ice sheet is by far the largest mass of ice on Earth.

The sheet contains enough ice to raise sea levels by 52 metres. The tipping point for this element lies at 7.5 degrees Celsius of global warming.

6. East Antarctica Subglacial Basins

Ice from subglacial basins in East Antarctica flows into the sea.

Three degrees of global warming is the tipping point for this element. Also in this case, sea levels would rise sharply as a result.

7. Atlantic Meridional Overturning Circulation

The overturning circulation of the Atlantic ensures that warm surface water is transported to the north. There, the water cools and sinks only to be transported south again. This process is called “thermohaline circulation”. Cold salt water is needed for this process. When glaciers melt, more fresh water enters the circulation. The circulation of the Atlantic Ocean could be paralysed.

This could have serious effects on temperature and precipitation distribution. The tipping point could be reached at 4 degrees Celsius.

8. Labrador-Irminger Seas Convection

As part of the so-called subpolar gyre, there is an overturning current in the Labrador and Irminger seas. Similar to the overturning circulation of the Atlantic.

The tipping point for this element threatens to be crossed in the next few years. A global warming of 1.8 degrees Celsius would be sufficient.

Should the circulation collapse, the regional environment will cool by two to three degrees Celsius. This may lead to more extreme weather events in Europe.

9. Amazon rainforest

The Amazon rainforest in South America has a major impact on the global water and carbon cycles. It absorbs gigantic amounts of CO₂ every year.

If we continue to deforest the Amazon and let fires spread, it can quickly reach the critical tipping point and die.

At 3.5 degrees Celsius, this tipping element could be triggered and the forest could die. It should be noted that deforestation has not been taken into account here.

What are the 7 regional tipping elements?

In addition to the global tipping elements, there are also regional tipping elements. These mainly have an impact on local climate conditions.

Nevertheless, regional tipping elements also have an impact on the planet as a whole. All climate systems are interconnected in various ways.

Here is a list of the 7 regional tipping elements:

1. Barents Sea Ice
2. Boreal Permafrost (abrupt thaw)
3. Extrapolar Glaciers
4. Northern Forest (southern dieback)
5. Northern Forest (northern expansion)
6. Low Latitude Coral Reefs
7. Sahel Vegetation and West African Monsoon

If we assume our current global warming trajectory, four tipping elements are currently at risk.

How are these tipping elements connected to our CO₂ emissions?

CO₂ is a greenhouse gas that contributes to global warming by trapping heat from the sun and shielding it in the Earth’s atmosphere.

An increase in CO₂ concentrations leads to more warming. Many tipping elements in the climate system are closely linked to CO₂ as they are triggered by global warming.

For example, the depletion of Arctic sea ice can lead to more heat entering the Arctic Ocean, accelerating melting, which in turn leads to the release of methane from permafrost soils.

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