As global warming brings increasingly higher temperatures, profound transformations to the Earth’s system have begun to unfold. The swindling of ice sheets in the Arctics, leading to the rise of sea levels, as well as the proliferation of wildfires…The severity of these impacts is believed to cause profound shifts to the functioning of the Earth’s system. Referred to as ‘tipping points,’ these are critical thresholds which, when breached, can lead to irreversible consequences.
Climate tipping points are when minor adjustments to natural processes in the functioning of the planet can reinforce loops, tipping the functioning global system from one stable state to a markedly different one. Not only a different state but, most importantly, an uncertain one. Rainforests could be transformed into arid deserts; coastal areas may find themselves completely under water; amongst other catastrophic and dangerous events. This transition is fueled by self-perpetuating feedback loops. The global system, like the forest in this scenario, may remain ‘tipped,’ even if temperatures drop below the critical threshold.
Feedback loops mean that the crossing of a specific tipping point can set off a chain reaction, activating other tipping elements and potentially rendering certain regions unsuitable for sustaining human and natural systems. The Arctics are quite a visual example, as its effects are so easily perceived year after year. The region faces warming almost four times faster than any other region globally. The effects from such are dire. Scientists believe they could, in turn, disrupt the ocean’s heat circulation, impacting the Atlantic Meridional Overturning Circulation (AMOC), subsequently influencing the monsoon system over South America and contributing to heightened droughts in the Amazon rainforest. This unchained process of seismic shifts in the Earth’s system are called a ‘tipping cascade’ – when multiple tipping points potentially lead to new ones and so on, with quite uncertain reverberations.
According to the recently released Global Tipping Points Report, five major tipping systems are currently at risk of surpassing tipping points at the current level of global warming: Greenland and West Antarctic ice sheets, permafrost regions, coral reefs, and the Labrador Sea and subpolar gyre circulation. When shall these tipping points be reached? In the early 2000s, a consensus among scientists argued that most tipping points could be reached in the event of a 4C-increase in global temperatures. However, more recent assessments found that exceeding 1.5C of global warming risks crossing several of these thresholds. That is why climate scientists across the globe have long called governments for more serious commitments to keep the global temperature rise below 1.5C. The IPCC describes this as a crucial necessity if we want to avoid the devastating impact of extreme weather events in the coming decades and, even worse, pass the burden on to future generations.
The liberation of greenhouse gas emissions – from the ever increasing use of fossil fuels, have led the Earth’s surface temperature to increase by nearly 1.2ºC compared with the average in 1850–1900 and the planet seems on track to reach the 1.5ºC threshold as soon as the year 2042, in a scenario where emissions are not rapidly reduced. A co-author from the Global Tipping Points Report, Sina Loriani from the Potsdam Institute for Climate Impact Research emphasizes that tipping-point risks should be taken ever more seriously, despite the several current uncertainties. Crossing these thresholds may determine the functioning of the Earth’s system in the centuries to come.
Sources: European Space Agency / The Guardian / Science.org (image)
Cover picture: Derek Oyen – unsplash.com
