Tipping Points

What could tip the world into runaway climate change?

Tipping point refers to a critical threshold at which a small change in human activity can have large, long-term consequences for the earth’s climate system.  Like the straw that broke the camel’s back. Many of these tipping points occurred in historical climate events.

  1. Melting of Arctic sea-ice
  2. Disruption of the West African monsoon
  3. Collapse of the Indian summer monsoon
  4. Dieback of the Boreal Forest
  5. Dieback of the Amazon rainforest
  6. Collapse of the Atlantic Ocean conveyer belt
  7. Increase in the El Nino Southern Oscillation
  8. Decay of the Greenland ice sheet
  9. Collapse of the West Antarctic ice sheet
  10. Methane release from permafrost

Tipping points represent irreversible changes on a human timescale.  The effects of the tipping event would be widespread and felt for centuries. The risk of reaching a tipping point  increases as global warming approaches 2C warming above pre-industrial temperature.

Tipping points #1-9 were first articulated by Dr. Timothy Lenton of the University of East Anglia and his colleagues at the Potsdam Institute of Climate Impact Research in 2008. Tipping point #10 is studied by the AMEG group of scienteists (www.ameg.me_)

Three tipping points affect Manitobans directly.

  • #1 – Arctic sea-ice melt. AMEG says that we have passed tipping point #1. It may not be possible to re-freeze the Arctic. Darker ocean surfaces amplify warming because it absorbs more radiation than white sea-ice. Warmer Arctic waters are affecting diversity of sea life and the food sources of Inuit. The habitat of sea animals, i.e. polar bear, is disappearing.
  • #10 – Methane release due to permafrost thaw.  Arctic communities are facing issues such as food insecurity, lack of safe drinking water and damage to infrastructure due to permafrost thaw. Methane leaks also occur during the extraction of oil, coal, and natural gas.
  • #4 – Boreal forest dieback occurs when forests die due to heat and drought conditions, increasing the risk of wildfires. Global warming of 3C could lead to large-scale dieback of the northern boreal forests as trees would be vulnerable to disease and insect infestations.