Tipping Points: The 9 steps on the road to environmental meltdown

Nine regions of the world face being tipped into massive, abrupt and potentially irreversible changes over the next century because of manmade global warming, researchers have said.

Scientists from 52 countries identified nine zones which they assessed to be where the world’s most dramatic climatic “tipping points” will be located and how long the decline will take. Each of the regions was judged to require just a small change in conditions to have a huge and disporportionate impact on the environment.

The Arctic ice sheet was among the areas identified and was judged to be likely to vanish in just ten years once its tipping point was reached. Similarly, the Amazon rainforest and the boreal forests of the northern hemisphere were assessed as likely to take 50 years to die back once rapid deterioration began.The decay of the Greenland and the West Antarctic ice sheets were each thought to take 300 years to undergo serious decline but would lead to a rise in sea levels of up to 12 metres if both disappeared.

The collapse of the Gulf Stream would take 100 years, as would an increase in the El Nino Southern Oscillation while the collapse of the Inian summer monsoon would take just a year to collapse. The greening of the Sahara and the collapse of the West African monsson was assessed as likely to take a decade to take place once past the tipping point.

Professor Tim Lenton, of the University of East Anglia, led the research and said: "Our findings suggest that a variety of tipping elements could reach their critical point within this century under human-induced climate change". The greatest threats are tipping of the Arctic sea-ice and the Greenland ice sheet, and at least five other elements could surprise us by exhibiting a nearby tipping point. The study, published in the journal Proceedings of the National Academy of Sciences, coined the phrase “tipping elements” to define the components of the climatic system that are thought to be at risk of reaching a tipping point, a point at which there is disproportionate and dramatic decline.

The 9 tipping elements and the time it will take them to undergo a major transition:

1 Melting of Arctic sea-ice (approx 10 years)

2 Decay of the Greenland ice sheet (more than 300 years)

3 Collapse of the West Antarctic ice sheet (more than 300 years)

4 Collapse of the Atlantic thermohaline circulation (approx 100 years)

5 Increase in the El Nino Southern Oscillation (approx 100 years)

6 Collapse of the Indian summer monsoon (approx 1 year)

7 Greening of the Sahara/Sahel and disruption of the West African monsoon (approx 10 years)

8 Dieback of the Amazon rainforest (approx 50 years)

9 Dieback of the Boreal Forest (approx 50 years)

Comments

[Henry]

When the snow is piling up against your
walls in ten years time, and mild winters and warm summers are but a distant memory, remember you wrote this article.

[Joe Horatio]

1 Tipping Point which would cause manmade global warming to go away in an instant

(1) Computers crash