1.7.2 Recommendations

Our section presents clear implications, as well as multiple research and institutional avenues for improving our understanding of Earth system tipping points.

Firstly and most importantly, reduction of human-driven pressures on the Earth system is critical in order to prevent destabilisation of the Earth’s tipping systems. In particular, most ESTPs considered in this section feature climate change as a key driver, and as such urgent and ambitious action to reduce GHG emissions to zero would reduce the chance of passing these tipping points. Many ESTPs in the biosphere are also driven by habitat loss and pollution – for example, deforestation and degradation in tropical forests or nutrient pollution in lakes and coastal ecosystems. Reducing these pressures would make climate-driven tipping less likely, as would efforts to bolster ecological resilience in these systems through restoration, legal protection and supporting sustainable livelihoods.

Secondly, key knowledge gaps can be addressed through improved observations and models of varying complexity. Despite our growing understanding of key Earth system feedbacks and interactions, some are currently not well represented in many computer models. As a result, tipping dynamics and interactions between tipping systems are less likely to emerge in model simulations, making comprehensive risk assessments difficult. To this end, it is necessary to better understand key feedbacks and interactions and resolve them in models, for example processes like marine ice cliff instabilities, feedbacks between meltwater and ocean circulations, small-scale mixing processes in ocean and atmosphere, and interactions between ecohydrological and fire feedbacks or spatial variability in the biosphere. These shortcomings can be systematically explored in tailored model intercomparison projects (MIPs), which are an established cornerstone of climate assessments. Insights from such modelling initiatives, together with palaeo evidence, observations and conceptual understanding of natural processes, can help guide the development of simpler models. Since their reduced complexity allows them to be run more often, they can help better understand uncertainties, for example around tipping point interactions, and can support interim risk analyses, together with expert elicitations.

Thirdly, improved palaeo reconstructions and observational data are key, both for developing better models and determining what systems may be at most risk. Remote sensing from space has allowed for global monitoring of vegetation cover over the last few decades, while in the ocean the RAPID array has allowed AMOC strength to be monitored for the past 20 years. However, these datasets are not yet long enough to be sure whether trends or early warnings they are detecting are outside of their natural ranges, while many parts of the ocean and biosphere have low observational coverage (in particular in the Global South). Continued and expanded observations would help improve and extend this coverage, while developing novel and improved early warning techniques could help mine this data to detect declining resilience and potential early warning signals. Of equal importance is the improvement of palaeo reconstructions, which in many cases has demonstrated that  different systems have tipped in the past, including many ice sheets and the AMOC. As the observational period reaches back only a few decades, palaeorecords are essential to extend our observations into the past, to improve our understanding of the tipping systems and potentially provide critical information needed for early warning. International data sharing and collaboration is also vital for improving monitoring of ESTPs, as is improving coverage in under-represented areas such as Africa and Asia.

Finally, it is clear that multiple different approaches are needed to understand the complexities of Earth system tipping points. As a result, integrating and co-designing research across natural and social sciences as well as other knowledge systems, including Indigenous and traditional ecological knowledge, can help better understand the drivers, dynamics and impacts of tipping in the Earth system.

Table 1.7.1: Summary of key drivers, biophysical impacts and confidence in tipping dynamics for each system considered in Section 1. Primary drivers, impacts and tipping systems are bolded. DC: Direct Climate driver (via direct impact of emissions on temperature/precipitation); CA: Climate-Associated driver (including second-order and associated effects of climate change); NC: Non-Climate driver; drivers can enhance (↗) the tipping process or counter it (↘). Tipping point key: +++ Yes (high confidence), ++ Yes (medium confidence), + Yes (low confidence), – – – No (high confidence), – – No (medium confidence), – No (low confidence).

System (and proposed tipping point)Key driversKey biophysical Impacts (see S2 for societal impacts)Evidence for tipping dynamics? (+ yes, – no, ? uncertain)
Ice Sheets (collapse)DC: atmospheric warming (↗)
DC: ocean warming and circulation changes
(↗ GrIS, WAIS, EASBs / ↘ GrIS)
DC: precipitation increase (↘)
DC: black carbon deposition (↗)
CA: sea ice decline (↗)CA: atmospheric circulation (?)
Sea-level rise resulting in global loss of coastal land over centuries to millennia
• Disruption of global ocean circulation
• Substantial shifts in atmospheric circulation patterns
• New ecosystems on exposed land
+++ Greenland
+++ West Antarctica
+++ Marine basins East Antarctica
++ Non-marine East Antarctica
Sea Ice (loss)DC: atmospheric warming (↗)
DC: atmospheric circulation shifts (↗/↘)
DC: ocean warming (↗)
DC: ocean circulation shifts (↗/↘)
DC: black carbon deposition (↗)
DC: storminess increase (↗)
CA: ocean stratification increase (↘)
Regional warming (polar amplification)
• Ecosystem disruption 
• Impacts on ocean circulation
• Impacts on atmospheric circulations
• Increased evaporation
– – – Arctic summer
– – Arctic winter
– Barents Sea

? Southern Ocean
Glaciers (retreat)DC: atmospheric warming (↗)
DC: deposition of dust, black carbon etc. (albedo) (↗)
DC: reduced snow (input and albedo) (↗)
DC: local thermokarst (↗)
• Water supply decline
• Ecosystem disruption (e.g. wetlands, water chemistry)
• Increase in number and size of glacier lakes
• Increase in slope instabilities
• Transition from glacial to paraglacial landscapes
• Sea-level rise
++ (regional)
– – (global)
Permafrost (thaw)DC: atmospheric warming (↗)
DC: ocean warming (subsea, ↗)

CA: vegetation change (increase: albedo , increase summer shading ↘; vice versa for dieback)
CA: wildfire intensity increase (↗)
CA: precipitation (rain extremes, snow cover albedo )
CA: sea ice loss (subsea, )
CA: water pressure reduction (subsea, )
Greenhouse gas emissions
• Landscape disruption
• Ecosystem disruption
++ land (regional)
– – land/subsea(global, 10s-100s years)
Tropical Forests (dieback)DC: atmospheric warming (↗)
NC: deforestation/degradation (↗)

DC: drying (↗)

CA: increasing fire frequency/intensity (↗)

DC: heatwaves (↗)
CA: ENSO intensification (e,g, Amazon, SE Asia,  ↗)
CA: AMOC/SPG weakening/collapse (e.g. Amazon,  ↗)
CA: terrestrial greening (↘, declining)
Biodiversity loss
• Regional rainfall reduction (e.g. from Amazon dieback across Amazon Basin and Southern Cone)
• Carbon emissions (amplifying global warming)
• Remote impacts on rainfall patterns all over the planet
+++ (Amazon, local)
++ (partial dieback/regional)
+ (full dieback/continental)
+ (Congo, local)
+? (SE Asia, local)
– – (regional)
Boreal Forests (dieback / expansion)DC: drying (↗)
CA: fire frequency/intensity increase (↗)

DC: atmospheric warming (↗)

CA: permafrost thaw (↗)

CA: insect outbreaks (↗)

NC: deforestation and degradation (↗)
DC: heatwaves (↗)
CA: terrestrial greening (↘)
CA: vegetation albedo (↗)
CA: sea ice albedo decline (↗)
DC: precipitation changes (?)
Biodiversity loss
• Carbon emissions (amplifying global warming) from southern dieback, carbon drawdown (reducing global warming) from northern expansion
• Complex regional biogeophysical effects on warming – dieback = higher albedo (cooling) but less evaporative cooling (warming) and vice versa for expansion
++ Southern dieback (partial/regional),
+ (continental)

+ Northern Expansion (partial/regional)
Temperate Forests (dieback)DC: atmospheric warming (↗)
DC: droughts (↗)

DC: heatwaves (↗)

CA: insect outbreaks (↗)
CA: windthrow (↗)
NC: deforestation and degradation (↗)
CA: fire frequency increase (↗)
NC: fragmentation (↗)
Biodiversity loss
• Carbon emissions (amplifying global warming)
• Regional warming in summer due to less evaporative cooling, less cloud cover
• Less atmospheric water supply
• Less groundwater recharge
? (partial / regional)
Savannas and Grasslands (regime shifts)NC: fire suppression (↗)
NC: overgrazing (↗)

DC: increased precipitation intensity (↗)
CA: terrestrial greening (↗)
NC: afforestation (↗)
CA: regional circulation changes (e.g. Sahel) (↗)
Biodiversity loss
• Greater groundwater depletion (with shrub encroachment)
• Nutrient cycle disruption
• Reduced fires (with shrub encroachment)
++ (local to landscape),
? (regional)
Drylands (regime shifts)DC: drying (↗)
DC: atmospheric warming (↗)

NC: land use intensification (↗)

DC: extreme events (heatwaves, floods) (↗)
DC: increased rainfall variability (↗)
CA: terrestrial greening (↘)
CA: insect outbreaks (↗)
CA: invasive species (↗)
• Biodiversity loss
• Aridification/desertification
• Groundwater depletion (with encroachment)
• Regional rainfall changes
• Shift in species composition (e.g. shrub encroachment)
++ (local to landscape),
+ (regional)
Freshwater / Lakes (regime shifts)NC: nutrient pollution (↗)
CA: terrestrial greening (↗)

NC: afforestation (↗)

DC: atmospheric warming (↗)
DC: precipitation changes (↗)
CA: permafrost thaw-related thermokarst formation/drainage (↗)
CA: glacier lake formation/drainage (↗)
DC: drought (↗)
CA: warming-driven species range expansion (↗)
CA: water use intensification (↗)
NC: human-mediated species introduction (↗)
Biodiversity loss
• Water quality decline

• Increased GHG emissions from most (reduced for salinisation)
+++ (eutrophication-driven anoxia, widespread localised)
++ (DOM loading, widespread localised in borea)
– (lake (dis)appearance, widespread localised in tundra)
– (N to P-limitation switch, localised in high N-deposition regions)
– (salinisation, localised in arid regions)
– (invasive species, widespread localised)
Coastal – warm-water coral reefs (die-off)DC: ocean warming (↗)
DC: marine heatwaves (↗)
CA: disease spread (↗)
CA: ocean acidification (↗)
NC: water pollution (nutrient / sediment) (↗)
NC: disruption (ships, over-harvesting) (↗)
CA: disease spread (↗)
CA: invasive species (↗)
DC: storm intensity (↗)
CA: sea level rise (↗)
• Biodiversity loss (ecosystem collapse, ~25% marine species have life stages dependent on coral reefs)
• Loss of commercial and artisanal fisheries, and other sectors
• Coastal protection loss
+++ (localised).
+++ (regionally clustered)
Coastal – mangroves and seagrass meadows (die-off)DC: increased climate extremes (e.g. tropical cyclones, marine heatwaves, El Niño intensity, droughts) (↗) 
NC: habitat loss (agri/aquaculture) and degradation (fishing damage) (↗)
CA: sea level rise (esp. mangroves, ↗)

NC: nutrient pollution (↗)

NC: shoreline change (erosion, sedimentation) (↗)

DC: ocean warming (seagrass, ↗)
CA: disease spread (seagrass, ↗)
NC: invasive species (seagrass, ↗)
Biodiversity loss 
Loss of coastal protection 
• Loss of carbon sink/increased GHG emissions
• Loss of water quality
• Sediment salinisation
• Subsidence
• Enhanced sediment sulphide and methane releases
• Hypoxia (seagrasses)
• Reduced nutrient recycling
++ (mangroves, regional)
++ (seagrasses, regional)
Marine ecosystems and environment (regime shifts)NC: over-exploitation (↗)
DC: ocean warming (↗)
NC: water pollution (nutrients/sediment) (↗)
NC: habitat loss (↗)
DC: marine heatwaves (↗)
Keystone species collapse
• Trophic cascades
• Regime shifts

• Changes to carbon sequestration
• Impacts on ocean biogeochemistry
• Major changes in ocean productivity, biodiversity and biogeochemical cycles
+++ (cod fisheries, regional)
+ (large fish fisheries, regional)
– (small fish fisheries, regional)
+ (marine communities, local)
+++ (kelp forests, local)
? (lipid pump, regional)
– – (gravitational pump, regional)
+ (marine hypoxia, local), ? (regional to global)
Ocean/Atmosphere Circulation
Ocean overturning (collapse)DC: ocean warming (↗)
DC: precipitation increase (↗)
CA: ice sheet meltwater increase (SO ↗, primary in the future for AMOC/SPG)

CA: river discharge increase (AMOC/SPG ↗)

CA: sea ice extent and thickness decrease (↗)
DC: regional aerosol forcing increase (↘)
CA: regional ocean circulation changes (?)
CA: wind trends (SO,↗)CA: sea ice formation (SO, ↗)
Cooling, change in precipitation and weather over Northern Hemisphere
• Change in location and strength of rainfall in all tropical regions
• Reduced efficiency of global carbon sink, and ocean acidification
• Deoxygenation in the North Atlantic  
• Change in sea level in the North Atlantic
• Modification of sea ice and arctic permafrost distribution
• Change in winter storminess
• Reduced land productivity in Atlantic bordering regions
• Increased wetland in some tropical areas and associated methane emission
• Change in rainforest response in drying regions
• Modification of Earth’s global energy balance, timing of reaching 2°C global warming
• Reduced efficiency of global carbon sink
• Change in global heat storage
• Reduced support for primary production in world’s oceans
• Drying of Southern Hemisphere
• Wetting of Northern Hemisphere
• Modification of regional albedo, shelf water temperatures
• Increase in summer heat waves frequency
• Collapse of the North Atlantic spring bloom and the Atlantic marine primary productivity
• Increase in regional ocean acidification
• Regional long-term oxygen decline
• Impact on marine ecosystems in the tropics and subtropics.
++ (AMOC)
++ (Subpolar Gyre)
++ (Southern Ocean)
Monsoons (collapse / abruptstrengthening)DC: increased water vapour in atmosphere (ISM ↘, WAM/SAM ↗)
NC: increased summer insolation (↘)
DC/NC: increased aerosols, dust (↗, ?)

NC: land-cover change, e.g. deforestation  (↗)
CA: desertification (↗)
CA: regional SST variations (?)
CA/NC: regional soil moisture/veg. variation (?)
CA: ENSO/Indian Ocean Dipole change (?)
CA: AMOC slowdown (SAM, WAM ↗)
CA: low cloud reduction (ISM ↘) 
CA: ocean warming (ISM ↗)
Massive change in precipitation
• Change in tropical and subtropical climates
• Biodiversity loss and ecosystem degradation 
+ (West African monsoon)
? (Indian Summer monsoon)
? (South American monsoon)
Tropical clouds and circulation  (reorganisation)DC: atmospheric warming (↗)
DC: ocean warming (↗)
• Massive alteration of hydrology in many regions
• Impact on ambient atmospheric phenomena such as ENSO
• Strong intensification of global climate change
– –
ENSO (more extreme or permanent)DC: East vs west Pacific warming (↗)
DC: increased water vapour in atmosphere (↗)

DC: weaker trade winds  (↗)
CA: MJO strengthening (↗)
• Temporary trade wind collapse during El Niño phase
• Increase in global mean surface temperatures during El Niño phase
• Modification of global atmospheric circulation
• Modification of worldwide patterns of weather variability
– –
Mid-latitude (shift to wavy-jet)CA: AMOC slowdown (↗)
CA: Mid-latitude flow weakening (↗)

DC: Arctic amplification (↗) 
• More persistent and slower-moving weather patterns
• Increase in extreme events on Northern hemisphere
Bezos Earth Fund University of Exeter logo
Earth Commission Systems Change Lab logo Systemiq logo
Global Tipping Points logo
Share this content