With five “disastrous” tipping points in the natural world at risk of being crossed right now, governments must urgently act to avoid “catastrophic damage,” say researchers who identified 26 such points of no return in a world racing towards exceeding the 1.5°C warming limit.
“The speed of fossil fuel phaseout and growth of zero-carbon solutions will now determine the future of billions of people,” write the 200 researchers who contributed to the Global Tipping Points Report, set to be unveiled at this year’s COP28 UN climate summit in Dubai.
The researchers note that even reaching net-zero by 2050 will not prevent the collapse of major ice sheets and widespread loss of warm-water coral reefs—two of five imminent negative tipping points, along with overturning circulation collapse in the North Atlantic subpolar gyre and widespread thawing of permafrost.
These tipping points, among others that include lost resilience of ecosystems like the Amazon rainforest, have potential for major impacts on human societies. But the report authors say past assessments of the human impacts of climate change include little information about the fallout from tipping points.
Thawing permafrost, for example, will disrupt hydrological dynamics, thereby producing “cascading effects” on the frequency and magnitude of floods, landslides, and coastal erosion, notes the report, coordinated by the University of Exeter with funding from the Bezos Earth Fund. Changes to boreal forests and tundra above permafrost areas will also affect local communities whose livelihoods and cultural heritage are “intimately tied to the health of the surrounding environment.” Infrastructure built on permafrost soil will also be threatened, and contaminants released into the environment will pose a great risk to humans.
‘Business as Usual is Over’
The authors urge decision-makers to strengthen adaptation and loss and damage finance, coordinate policy efforts, deepen research, and address tipping points in their Nationally Determined Contributions (NDCs), the voluntary climate commitments that countries produce under the 2015 Paris Agreement.
“These extremely high stakes place a major burden of responsibility on the present generations and—unlike other global challenges—dramatically elevate the logic of precaution,” the authors say, adding that uncertainty about how close a tipping point is should not delay action.
“The existence of tipping points means that ‘business as usual’ is now over,” they add. “Rapid changes to nature and society are occurring, and more are coming.”
Citing another example of a tipping point—“the collapse of the Atlantic Ocean’s great overturning circulation combined with global warming could cause half of the global area for growing wheat and maize to be lost”—the authors add that the current governance approach of linear, incremental change is “no longer an option.”
Instead, “transformational change” is the only match for natural tipping points—those critical thresholds beyond which a relatively small change can lead to significant and often irreversible consequences. Climate change is driving systems towards these tipping points and leading to profound shifts that will affect ecosystems and societies worldwide.
Mass displacement, political instability, and financial collapse are potential outcomes, said Prof. Tim Lenton of Exeter’s Global Systems Institute.
But he added that “tipping points also offer our best hope,” and points to positive tipping points—a relatively new approach that the report notes can accelerate the transition to sustainable, post-carbon societies.
Positive Tipping Points Offer Hope
Positive tipping points must be triggered and harnessed, the researchers say, as they aim to prevent the negative impacts of global heating and [Earth-system tipping points]”. Those changes must go beyond preventing harm to actively bring about system shifts that “increase the likelihood of achieving the just social foundations of sustainability.”
(Report authors include a caveat that ‘positive’ is a value judgement, so some people—those with jobs within the fossil fuel sector—might still be negatively affected by rapid decarbonization in the absence of a deliberate, well-planned transition.)
Unlike negative tipping points, positive ones require intentional changes that are actively brought about through innovation, shaping markets, regulating business, and educating and mobilizing the public.
“Just as with Earth system tipping points, positive tipping points can combine to reinforce and accelerate each other,” explained Exeter’s Dr. Steve Smith. “For example, as we cross the tipping point that sees electric vehicles become the dominant form of road transport, battery technology continues to get better and cheaper.”
That shift, in turn, “could trigger another positive tipping point in the use of batteries for storing renewable energy, reinforcing another in the use of heat pumps in our homes, and so on.”
Progress towards some of these positive tipping points is already well under way, as in the rollout of solar and wind power generation, which have yielded record investment and implementation as policy and technological advancements lower production costs. But to reach a positive tipping point, these gains must also be driven by policies that trigger behavioural feedback loops, prompting sectors to reduce demand and improve efficiency.
“Human history is full of examples of abrupt social and technological change,” and “many areas of society have the potential to be ‘tipped’ in this way, including politics, social norms, and mindsets,” Smith said. “Learning from these examples, we must switch our focus from incremental change to transformative action—tipping the odds in our favour.”
