Climate change tipping points are positions in an evolving situation that lead to a new and irreversible development.
Some of these tipping points have already been crossed. The methane that escaped from under melting polar ice can not be put back. Melted ice that formed in the Alps 25,000 years ago would take at least 25,000 years to recreate. Permafrost is melting in Greenland, Alaska, Russia, China, and Eastern Europe. As these frozen soils warm, the ground destabilizes, methane is released, well-preserved woolly mammoths are exposed. The Iberdrola group reports, "Melting Siberian permafrost is turning parts of the tundra into muddy landscapes, causing the local flora to disappear and the wildlife that feeds on it to starve. Furthermore, when the permafrost beneath water bodies, such as lakes, melts, the water seeps into the ground and disappears, causing droughts." None of these changes can easily be restored. Methane is one of the most significant causes of global warming. The release of methane from ancient storage results in a feedback loop -- the released methane causes further warming. In turn, the further warming releases more methane.
Climate Tipping Points
"A decade ago we identified a suite of potential tipping points in the Earth system, now we see evidence that over half of them have been activated," said lead author Professor Tim Lenton, director of the Global Systems Institute at the University of Exeter in 2019.
"The growing threat of rapid, irreversible changes means it is no longer responsible to wait and see. The situation is urgent, and we need an emergency response."
Nine active tipping points:
* Arctic sea ice
* Greenland ice sheet
* Boreal forests
* Atlantic Meridional Overturning Circulation
* Amazon rainforest
* Warm-water corals
* West Antarctic Ice Sheet
* Parts of East Antarctica
Triggering Multiple Climate Tipping Points
As this study concludes, we have already crossed some tipping points. Tipping points are climate change triggers that will last for 1,000's or many 1,000's of years beyond the ending of human emissions.
"Their analysis indicates that even global warming of 1°C, a threshold that we already have passed, puts us at risk by triggering some tipping points. This finding provides a compelling reason to limit additional warming as much as possible."
We are currently 1.1C above -- "risks increase with each tenth of a degree of further warming."
Research, said: "The world is heading towards 2-3°C 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, protect people from rising extremes, and enable stable societies, we must do everything possible to prevent crossing tipping points.
CONCLUSION: Exceeding 1.5°C global warming could trigger multiple climate tipping points
"Our assessment provides strong scientific evidence for urgent action to mitigate climate change. We show that even the Paris Agreement goal of limiting warming to well below 2°C and preferably 1.5°C is not safe as 1.5°C and above risks crossing multiple tipping points. Crossing these CTPs can generate positive feedbacks that increase the likelihood of crossing other CTPs. Currently the world is heading toward ~2 to 3°C of global warming; at best, if all net-zero pledges and nationally determined contributions are implemented it could reach just below 2°C. This would lower tipping point risks somewhat but would still be dangerous as it could trigger multiple climate tipping points."
"Remember these numbers have error bars on them. So if we think a tipping point might not be exceeded at 1.5C, we might be wrong, and have already exceeded it at 1C," said climate scientist Sidd Mukherjess. In fact, many tipping points have already been triggered, and they triggered a cascading number of other tipping points. Melting sea ice results in a darker, heat absorbing ocean surface. The warmer ocean triggers further ice melt resulting in more dark ocean surface. This feedback loop also triggers increased methane being released. Increased methane emissions trigger melting permafrost. Melting permafrost releases more methane. More methane triggers more sea ice and permafrost melting.