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Concern over climate tipping points (CTPs) is developing on the levels of science, politics, and the general public. They occur when large-scale climate change—called tipping elements—becomes self-sustaining above a warming threshold. Major, policy-relevant effects of Climate Tipping Points include significant sea level rise from melting ice sheets, the decline of biodiverse biomes like the warm-water corals or Amazon rainforest, and carbon release from permafrost thawing. According to a significant study, the climate catastrophe has brought the globe dangerously close to many “disastrous” tipping points. It demonstrates that five potentially disastrous tipping points may have already been reached due to the 1.1degree Celsius of global warming brought on by human activity.
Key takeaways
- Concern over climate tipping points (CTPs) is developing on the levels of science, politics, and the general public
- Due to a lack of information and the difficulties in accurately simulating these processes in climate models, it is difficult to predict if any tipping points will be reached before 2100.
- As a result, there is considerable uncertainty in any estimate of a certain tipping point.
- To avoid several tipping points being reached, many scientists have advocated that a safe limit of 2°C for global warming should be used.
Meaning of Tipping Points
A tipping point is when a tiny change becomes significant enough to trigger a more prominent, more important factor that can be sudden, irreversible, and have cascading repercussions. When the IPCC introduced the idea of tipping points 20 years ago, it was believed that they would only happen if global temperature hit 5°C. On the other hand, recent IPCC assessments indicated that tipping points might be reached between 1° and 2° of warming.
Some Major Climate Tipping Points
Greenland ice sheet
The Greenland ice sheet is rapidly melting, storing enough water to increase global sea levels by more than 20 feet. It lost close to four trillion tonnes of ice between 1992 and 2018. Its eventual collapse may not happen suddenly, but there may come the point past which it will be unstoppable for millennia.
According to a recent study, the Jakobshavn basin, one of Greenland’s fastest melting basins, and the height of the ice sheet are causing the ice sheet to become unstable. Since temperatures are rising, most melting occurs on the ice surface. Still, as the ice sheet’s height decreases, the surface becomes open to warm moist air at lower elevations, which has the effect of hastening to melt.
Amazon Rainforest
The largest tropical rainforest in the world, the Amazon, is also home to millions of different plant and animal species. Its 200 billion tonnes of carbon dioxide storage capacity is about five years’ worth of the world’s fossil fuel-related carbon emissions. Rainfall from the Amazonian rainforest evaporates from the soil and evaporates from plants, returning moisture to the sky. More rain falls as a result of this self-sustaining mechanism.
Due to a 1°–1.5°C increase in temperature during the past century, the Amazon is already experiencing the impact of climate change. Due to more prolonged and hotter dry seasons, decreased evapotranspiration brought on by increased CO2 levels, and the emergence of more drought-tolerant tree species, the Amazon is becoming more susceptible to flames.
Thawing permafrost
Permafrost is a mixture of ice, rock, soil, and sediments trapped for two or more years. For tens of thousands or even hundreds of thousands of years, certain permafrost has been frozen. It can be found in sections of Alaska, Siberia, northern Canada, and Tibet in the northern hemisphere, where there are no glaciers. Permafrost can be found in portions of Antarctica, the Southern Alps of New Zealand and Patagonia in the Southern Hemisphere.
Permafrost in ocean sediments contains methane that is stored in hydrates, which are ice-like structures. As hydrates thaw from the warming saltwater, this methane might be released. In the East Siberian Arctic Ocean, beneath the permafrost of the Laptev Sea, scientists recently detected methane escaping from a massive old methane reservoir.
Arctic Sea
Higher summer temperatures and a feedback loop cause more ice to melt. This implies that as the ice melts, more ice also melts. More of the ocean’s surface is exposed as the ice melts. Ice is lighter in colour than the ocean’s surface, which allows it to reflect less sunlight. As a result, it is increasingly likely that additional ice will melt as more of it melts and as the ocean surface gets hotter.
When temperatures rise to a point where it is impossible to stop further sea ice loss, the Arctic sea ice will tip over. In the future, there won’t be any summer sea ice in the Arctic due to this. The local wildlife and indigenous peoples’ access to food and water will suffer significantly from the melting of Arctic sea ice. Many more people could be affected by the weather patterns that could change across much of the northern hemisphere. But the mechanics of this association are a matter of some debate among scientists.
Interactions in Tipping Points
The WAIS, Greenland ice sheet, AMOC, ENSO, and Amazon rainforest tipping points could interact before temperatures rise by 2°C, according to a recent study. Due to this interaction, tipping could operate at lower levels than previously thought. Because the ice sheets’ critical thresholds are lower, the risk analysis discovered that a cascade might potentially start with their melting. The AMOC may slow, for instance, as freshwater is released into the North Atlantic by the Greenland ice sheet. Less heat would be carried northward as a result of this.
The Greenland ice sheet might become more stable if the North became colder. The Southern Ocean would also get warmer, which might cause more drought in some regions of the Amazon while increasing rainfall in others. The actual threshold for Amazon dieback may be lowered by the effects of changes in the AMOC on ENSO, which may result in a more persistent El Nino state.
