The most extensive compilation study carried out so far on climate tipping points warns about the chain effects they can unleash on the planet's ecosystems.
This is indicated by this documented work, which points out that the world has entered a crucial phase in history as the threats posed by these turning points in nature are accelerating.
According to the Global Tipping Points report, the planet is already at risk of crossing five major natural thresholds, and three more may be reached in the 2030s if the world warms 1.5°C above pre-industrial temperatures.
The pace at which the phasing out of fossil fuels is addressed and the speed at which carbon-free solutions are delivered will determine the future of the planet, they say.
A tipping point occurs when a small change triggers an often rapid and irreversible transformation. When a climate system crosses a certain threshold and suffers a sudden shock, it can permanently alter the way the planet functions.
Tipping points at risk include the collapse of large ice sheets in Greenland and West Antarctica, widespread thawing of permafrost, the death of coral reefs in warm waters, and the collapse of atmospheric circulation in the North Atlantic.
Based on the assessment of 26 tipping points in Earth systems, the report concludes that rapid changes are already occurring in nature and societies.
Scientists warn that there are great uncertainties about when this type of turnaround can occur, with changes in these systems, but they judge that three more of them could soon join the list.
They are mangroves and seagrasses, which are expected to die in some regions if temperatures rise by 1.5°C to 2°C, and boreal forests, which may experience warming as soon as 1.4°C or as late as 5°C.
Tipping points are not isolated, but rather interconnected, which can lead to a chain or cascade effect.
For example, the melting of the Greenland ice sheet may lead to an abrupt change in the ocean circulation of the Atlantic whose current warms the waters of Europe.
And in the same way, permafrost thaws or the death of trees can release huge amounts of CO2 that have been stored in forests or under frozen lands, with effects that can feed back and amplify in the atmosphere.
Some of the changes could create feedback loops that further warm the planet or alter weather patterns in a way that triggers other tipping points.
The report says that the current mode of global governance is inadequate in the face of the magnitude of the challenge and launches six key recommendations to change course quickly, including coordinated action to unleash a gear that activates a dynamic of positive inflection points.
The risk of crossing biosphere tipping points can be reduced by an approach that combines action on climate mitigation and on other interacting factors, such as deforestation and habitat loss or pollution, together with ecological restoration, conservation inclusiveness and support for sustainable livelihoods.
As Earth system tipping points multiply, there is a risk of catastrophic global-scale loss of the ability to produce staple crops, researchers say
"Without urgent action to stop the climate and ecological crisis, societies will be overwhelmed as the natural world falls apart."
"Tipping points in the Earth system pose threats of a magnitude never before faced by humanity," said Tim Lenton of the Exeter Global Systems Institute.
In his opinion, these turning points or no return can trigger devastating domino effects, including the loss of entire ecosystems and the productive capacity of crops, “with social impacts that include massive displacements, political instability and financial collapse.”
The report was produced by an international team of more than 200 researchers, coordinated by the University of Exeter, in partnership with the Bezos Earth Fund.
Together, these tipping points threaten the livelihoods of millions of people, and some thresholds are likely to be breached. Stabilizing the climate is critical to reducing the likelihood of widespread tipping points in ecosystems, but addressing other pressures can also help increase ecological resilience, delay tipping points, and support human well-being. Key messages.
Meanwhile, the study's authors are optimistic that emergency global action – accelerated by leaders now meeting at COP28 – can guide positive turning points towards a prosperous and sustainable future.
The report lays out a plan to achieve this and says bold, coordinated policies could trigger positive tipping points across multiple sectors, including energy, transport and food.
They expand on this argument by saying that a cascade of positive tipping points would save millions of lives and free millions of people from hardship, while avoiding trillions of dollars in climate-related damage while beginning to restore the world. nature on which we depend.
The report also cites among these examples the recent expansion of renewable energy. As with negative tipping points, positive ones interact and one can trigger others. Positive tipping points could help mitigate the dangers described above, but require decision makers to act.
Scientists have also concluded that reducing emissions to zero by 2050 – or at least the way policymakers are trying to achieve this plan – is not enough to avoid this catastrophic damage. Researchers point out that the threat posed by the climate and ecological crisis is much more serious than believed, and that these changes could overwhelm societies as the natural world rapidly collapses, if there is no governance response. transformative on the part of policy makers.
"Tipping points in the Earth system pose threats of a magnitude never before faced by humanity," said Tim Lenton of the Exeter Global Systems Institute. “They can trigger devastating domino effects, including the loss of entire ecosystems and the ability to grow staple crops, with social impacts including mass displacement, political instability and
financial collapse," he notes. But "they also offer our best hopes," which is already happening in areas ranging from renewable energy, electric vehicles, and social movements in favor of plant-based diets.
“Currently, our global governance system is inadequate to address upcoming threats and implement urgently needed solutions,” says Manjana Milkoreit of the University of Oslo.
"Some tipping points in the Earth system are likely to be triggered now and will cause severe and disproportionate impacts within and between nations," he adds. For this researcher, this is the opportunity to make an urgent push to strengthen adaptation and loss and damage governance, adjust existing legal frameworks and increase resources to take into account the threats of tipping points. .
“Avoiding this crisis – and doing so equitably – must be the central objective of COP28 and ongoing global cooperation.
"Good global governance can make this happen, especially by triggering positive turning points."
