What do you mean, ‘Tipping Point’?

Fold bifurcation

Saddle point

Homoclinic bifurcation

Torus destruction

Supercritical Hopf bifurcation

Subcritical Hopf bifurcation

Turing instability

Phase locking

Arab spring

End of foot-binding

Public smoking

Forest die-back

Lake turbidity

Coral bleaching

Stockmarket crash

Depression

Epileptic seizure

Heart failure

Fainting

Greenland Icecap

Indian Monsoon

Gulfstream

?

Use of the term

1970 1980 1990 2000 20100

50

100

150

200

year

# ar

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allenvironmental

What do you mean, ‘Tipping Point’?2016

Use of the term

Malcolm Gladwell’s book “The Tipping Point” (2000)

Grodzins 1957 Racial Segregation

A situation where a small impact can cause “runaway change”

Driven by “positive feedback”

What do you mean, ‘Tipping Point’?

Slowing down precedes ancient climate shifts

Dakos et al PNAS 2008

Climate Tipping Points Evidence from the past

Vasilis Dakos

Abrupt Shifts

Critical Slowing

down

Critical Slowing Down Indicates loss of resilience

In the vicinity of Tipping Points

Critical Slowing Down Indicates loss of resilience

In the vicinity of Tipping Points

As Critical Slowing Down preceded past climate transitions

these ‘abrupt’ shifts were likely due to Tipping Points

But can we also predict future shifts?

Slowing down precedes ancient climate shifts Insights from models

Vasilis DakosPNAS 2015

Expert Views

Tim Lenton et al. PNAS 2008

ObservationsModels

We are quite certain that the Earth has Tipping Points

But we are uncertain where and when

So what should we do?