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Earth on ‘devastating trajectory’ to global tipping points. But there’s hope.

image: The authors of the report identify five major tipping points as the melting of both the Greenland and West Antarctic ice sheets, the mass die-offs of warm-water reefs, the overturning of the North Atlantic subpolar gyre circulation and the thawing of permafrost. Image by Gian-Reto Tarnutzer via Unsplash (Public domain).
  • A new report on global tipping points warns of imminent serious disruptions in major Earth systems if global temperatures continue rising due to human-induced climate change.
  • It suggests that current levels of warming will likely push five major Earth systems past their tipping points, and another three will follow if global temperatures exceed 1.5° Celsius (2.7° Fahrenheit) of warming above preindustrial levels.
  • However, along with these dire warnings, the report also notes the launch of positive tipping points within society, such as the rollout of renewable energy technologies.
  • Other reports also describe the urgency to enact positive change as humanity continues pumping carbon into the atmosphere, wreaking havoc on the environment.

A new report suggests that the rapid acceleration of climate change has pushed the Earth systems humanity relies upon to the brink of collapse, placing the world on a “devastating trajectory.” However, coordinated efforts to reduce humanity’s impacts on the planet, including the phasing out of fossil fuels, could still ensure a sustainable, livable future, the report says.

The Global Tipping Points report, produced by a team of more than 200 international researchers and released Dec. 6 during the COP28 climate summit in Dubai, suggests that current levels of warming will very likely push five major Earth systems to reach their “tipping points,” resulting in widespread impacts to humanity and nature. A tipping point, in the context of this report, refers to a moment when a small added change can make a big difference in a system, leading to abrupt, self-perpetuating or irreversible changes.

The authors identify these five major tipping points as the melting of both the Greenland and West Antarctic ice sheets, the mass die-offs of warm-water reefs, the overturning of the North Atlantic subpolar gyre circulation and the thawing of permafrost.

Tim Lenton, a professor of climate change and Earth system science at the University of Exeter and lead author of the new report, said the “grave risk” of crossing these five tipping points would lead to “serious if not almost unimaginable impacts” for humanity and nature. At the same time, he views these looming tipping points as “early opportunity signals” that, if heeded, can lead to positive tipping points within society.

“The only way we’re going to credibly respond now to reduce those profound risks is to find and trigger some positive tipping points that accelerate the change to zero greenhouse gas emissions,” Lenton told Mongabay in an interview.

If the world exceeds average preindustrial global temperature levels by 1.5° Celsius (2.7° Fahrenheit) in the early 2030s, the report notes that another three tipping points will likely be crossed: the deterioration of boreal forests, mangroves and seagrass meadows — all of which store massive amounts of carbon, and whose destruction would ramp up global warming.

While it is unclear when exactly the world will breach 1.5°C of warming, another recent report by the Global Carbon Project suggests this could happen in about seven years. Moreover, this report found that the world will likely produce more carbon dioxide emissions in 2023 than it did in 2022, at a time when carbon emissions need to be urgently reduced.

Seagrass meadows.
If the world exceeds average preindustrial global temperature levels by 1.5° Celsius (2.7° Fahrenheit) in the early 2030s, the report notes that another three tipping points will likely be crossed: the deterioration of boreal forests, mangroves and seagrass meadows. Image by Benjamin L. Jones via Unsplash (Public domain).

In total, the Global Tipping Points report identified 26 Earth system tipping points that could be crossed if global temperatures continue to rise in response to human-induced climate change. According to the researchers, the full impact of breaching these tipping points would be “far greater than their initial impact.”

“The effects will cascade through globalized social and economic systems, and could exceed the ability of some countries to adapt,” the authors say. “Negative tipping points show that the threat posed by the climate and ecological crisis is far more severe than is commonly understood and is of a magnitude never before faced by humanity.”

The authors underscore the likely possibility that the crossing of one tipping point could trigger others, “causing a domino effect of accelerating and unmanageable change to our life-support systems,” in a world that lacks the global governance to deal with such overwhelming events.

But the authors also report on positive changes already underway in society, changes which could pick up speed with sufficient commitment and effort, including the rollout of renewable energy technologies, increased globalized efforts to reduce emissions and restore nature and even humanity’s shift to more plant-based diets.

The report makes several recommendations, including the phasing out of fossil fuels and land-use carbon emissions, increased adaptation to climate losses and the strengthening of tipping point systems knowledge bases and policies. It also recommends that Earth system tipping point risks and positive tipping point opportunities be included in the Global Stocktake (GST) — a tool used to monitor global climate action to reach the goals of the Paris Agreement — as well as future revisions of Nationally Determined Contributions (NDCs) and related policy measures. A new draft of the GST was released on Dec. 11 of the COP28, but it raised concerns for only calling for a “reduction” in fossil fuels rather than a “phase-out.”

Lenton, who attended the COP28 summit in Dubai, said he believes that many people, including policymakers, are still not aware of the “escalation of risks” that can occur when Earth systems pass tipping point thresholds, but that this awareness is now growing as extreme weather events rock the planet.

“We see some positive signs that some nations are really switching on to these issues,” Lenton said. “And as with all tipping points, some will be the leaders of recognizing the importance of [these issues], and others will be the followers recognizing it.”

A month before the COP28 climate summit, the United Nations University (UNU) released another report on tipping points, the Interconnected Disaster Risks Report. The tipping points referred to in this report encompass other life-sustaining Earth systems that are being heavily impacted by humanity, resulting in accelerating extinctions, groundwater depletion, the melting of mountain glaciers, an accumulation of space debris, unbearable heat and the impacts of extreme weather that can no longer be covered by insurance.

“We chose to think about our systems and our risks in a more interconnected way by connecting climate change to the many other changes humans are exposing the planet to such as loss of nature, the extraction of water resources, or the unsustainable use of space for satellite infrastructure,” Zita Sebesvari, deputy director of UNU’s Institute for Environment and Human Security and lead author of the UNU report, told Mongabay in an email. “What connects both reports is the strong desire to bring along response options to avoid the tipping points.”

Speaking about the report led by Lenton, Sebesvari said, “I very much welcome this highly valuable and very thorough analysis of climate-related tipping points of the Earth System, especially the section on positive tipping points in technology, economy and society [which] is highly valuable as it showcases enablers of positive change.

“Far too often, we are not paying enough attention to our options to bring along positive change — seemingly we tend to be more drawn to the negative news,” said Sebesvari.

Elizabeth Claire Alberts is a senior staff writer for Mongabay. Follow her on Mastodon, @[email protected], and Blue Sky, @elizabethalberts.bsky.social.

Citations:

Lenton, T. M., Armstrong McKay, D. I., Loriani, S., Abrams, J. F., Lade, S. J., Donges, J. F., … Laybourn, L. (2023). Global Tipping Points Report. Retrieved from University of Exeter website: https://global-tipping-points.org/

UNU-EHS Interconnected Disaster Risks 2023: Risk Tipping Points. (2023). Retrieved from United Nations University – Institute for Environment and Human Security website: https://interconnectedrisks.org/download

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