Case Studies

Risk assessment

The Amazon is approaching ecological tipping points due to interacting climate and land-use feedbacks that threaten to trigger large-scale forest degradation and regime shifts in the range 1.5-2 °C global warming.

These changes risk transforming forested areas into altered ecosystems, weakening global climate regulation, altering regional climate and accelerating biodiversity loss.

Negative social tipping points, including displacement, health impacts and cultural erosion are unfolding alongside ecological forest transitions, especially among
Indigenous and traditional populations.

These impacts and risks remain significantly under-addressed in climate policy and are intensified where governance fails to secure land rights, or enforce protections, or support adaptation.

Indigenous Territories and Protected Areas exhibit strong climate mitigation potential, underscoring their vital role in maintaining carbon stocks and resisting
ecosystem collapse.

In contrast, undesignated Public Forests account for the majority of carbon losses from degradation, reflecting the consequences of weak governance and land tenure insecurity.

Without immediate action, cascading risks could result in irreversible losses to both ecosystems and communities, undermining regional and global sustainability.

Recommendations

The Amazon forest holds global significance as a biocultural and climatic -regulating system; safeguarding it requires urgent, justice-centered strategies that integrate understanding of ecological thresholds, social vulnerability and climate adaptation.

Positive social tipping points can be catalyzed by inclusive and polycentric governance, recognition of traditional knowledge systems and targeted financial investments in forest conservation, restoration and supporting Indigenous People and Communities
Territories and their livelihoods.

These interventions have the potential to reverse degradation feedbacks and ensure socio-ecological resilience across the Amazon.

Risk assessment

Warm-water coral reefs are vital to the wellbeing of up to a billion people and almost a million species.

Globally, coral reefs are experiencing unprecedented mortality under repeated mass bleaching events, highlighting the impact that global warming (interacting with other, predominantly human-driven environmental stressors) is already having.

The central estimate of the thermal tipping point for warm-water coral reefs of 1.2°C global warming above pre-industrial is already exceeded and without stringent climate mitigation their upper thermal threshold of 1.5°C may be reached within the next 10 years, compromising reef functioning and provision of ecosystem services to millions of people.

Even under the most optimistic current emission scenarios of stabilising warming at 1.5°C without any overshoot, it is considered that warm-water coral reefs are virtually certain (>99% probability) to tip, given the upper range of their thermal tipping point is 1.5°C.

The goal of the Paris Agreement to limit global warming “well below 2°C” or 1.5°C will not prevent coral reefs from irreversibly passing their thermal tipping point.

Recommendations

Returning global mean warming below 1.2°C with a minimal overshoot period and eventually returning to 1°C above preindustrial is essential for retaining functional warmwater coral reefs at meaningful scale, beyond a relatively few isolated refuge areas.

Minimising non-climatic stressors, particularly by improved reef management, can give reefs the best chance of surviving under what must be a minimal exceedance of their thermal tipping point.

Risk assessments and urgent policy responses are needed to address the ecosystem and livelihood impacts of degraded or nonfunctional reefs.

Risk assessment

Mountain glacier tipping behaviour depends on a complex interplay between topography and climate, with mountain glaciers that experience similar external forcing having the potential to respond differently depending on local conditions.

Áakʼw Tʼáak Sítʼ and other outlet glaciers of the Juneau icefield, Alaska, have been suggested as a potential mountain glacier tipping system, with ice segregation and the bedrock hypsometry leading to nonlinear
mass loss and glacier retreat.

Rapid deglaciation of Áakʼw Tʼáak Sít and other glaciers disrupts the relationship between Indigenous communities, glaciers and glacial landscapes, depriving future generations of this component of their identity and history, which are inseparable from the land.

The retreat of Áakʼw Tʼáak Sítʼ’s tributary glaciers has led to annual outburst floods in Juneau, the future occurrence of which will depend on rates of ice retreat, the pattern of retreat and the formation of future glacier separations.

Rapid mass loss of Áakʼw Tʼáak Sítʼ could negatively impact tourism in Juneau as the glacier retreats from the Mendenhall Glacier Visitor Center viewshed, where an average of every third visitor to the state of Alaska visits.

The economic consequences of tipping on fishing and salmon stocks are less clear, giving the complex interplay between water temperature, air temperature and riverbed scouring, all of which impact aquatic ecosystems.

Recommendations

Anticipatory governance considerations at the local level regarding glacier loss must involve multiple partners and rights holders , including Indigenous community governments, federal and state agencies and local government, as well as community members, particularly in the context of resource management and the opening of navigable U.S.-Canada border crossings,
following ice retreat.