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Numerical models predict that during an oceanic anoxic event (OAE), increased organic carbon burial drives a rise in atmospheric oxygen leading to the event’s termination. Here, the authors present evidence suggesting that the Toarcian OAE was terminated by rising oxygen and associated fire-feedbacks.

Global oxygen regulation over Earth history has largely depended on variations in organic carbon burial, which includes the suppression of land vegetation due to fires. Here, the authors show that major evolutionary changes in plant ecosystems could have influenced fire regimes and thus affected atmospheric O₂.

The evolution of complex animal life in the Cambrian period is thought to be related to oxygenation of the Earth System, however the timing, magnitude and mechanism of this oxygenation event remain uncertain. Here, the authors use a biogeochemical model which links tectonic CO₂ degassing rates to carbon and sulphur burial, and suggest that atmospheric pO₂ increased by ~50% during the Ediacaran Period.

A shift in organic carbon to total phosphorus (C_org/P_total) ratios in marine siliciclastic strata from approximately 455 million years ago suggests an earlier-than-previously-thought spread of land plants and their impact on the Earth system, based on analogy with extant C/P ratios of terrestrial and marine organic matter.

Periodic marine oxygen oscillations occurred throughout the middle Ediacaran Gaskiers Glaciation, probably stemming from increased organic carbon burial destabilizing ocean redox systems, according to geochemical constraints and modelling.

We find that justice considerations constrain the integrated Earth system boundaries more than safety considerations for climate and atmospheric aerosol loading, and our assessment provides a foundation for safeguarding the global commons for all people.

Early Neoproterozoic marine productivity fell due to nutrient drawdown following a switch from an iron-rich to a sulfide-rich ocean, according to records of phosphorus geochemistry measured from sedimentary sections in North China.

As an alternative to monetary estimates, this study expresses the costs of climate change in terms of numbers of people left outside the ‘human climate niche’, which reflects the historically highly conserved distribution of human population density relative to mean annual temperature.

The growing threat of abrupt and irreversible climate changes must compel political and economic action on emissions.

This study provides evidence of a cascading positive tipping point towards electric vehicles, which has occurred or lies within the next few years in lead markets of the EU and China, and potentially the US, and it could spill out into peripheral vehicle marketss across the rest of the world.

An analysis of 24,202 critical cases of COVID-19 identifies potentially druggable targets in inflammatory signalling (JAK1), monocyte–macrophage activation and endothelial permeability (PDE4A), immunometabolism (SLC2A5 and AK5), and host factors required for viral entry and replication (TMPRSS2 and RAB2A).

Integrated assessment modelling backed by expert judgement indicates that the existence of future multiple interacting climate tipping points, with irreversible economic damages, greatly increases the social cost of carbon.

Collapse of the Atlantic Meridional Overturning Circulation (AMOC) will impact agricultural land use and its economic value in Great Britain. Ritchie et al. model the impacts of smooth (conventional climate change) and abrupt (tipping point change) AMOC collapse on land use, arable farming and related economic outputs in Britain, as well as the economic feasibility of technological adaptations such as widespread irrigation.

Early warning systems can alert societies about coming irreversible climatic changes, but can they trigger action to avoid them? Research now suggests that to prompt social action, uncertainty about when the changes will occur must be reduced.

Integration of phylogenetics, comparative genomics and palaeobiological approaches suggests that the last universal common ancestor lived about 4.2 billion years ago and was a complex prokaryote-grade anaerobic acetogen that was part of an ecosystem.

Analysis of the uncertainty associated with the timing of climate tipping points suggests that carbon taxes need to be increased by a minimum of 50%. If considering a rapid, high-impact tipping event, these taxes should be more than 200% higher. This implies that the discount rate to delay stochastic tipping points is much lower than that for deterministic climate damages.

A 1.5-fold gap exists in green space cooling adaptation between cities in the Global South and North. Enhancing urban green space quality and quantity offers vast potential for improving outdoor cooling adaptation and reducing its global inequality.

Evaporite dissolution coupled with pyrite burial can lead to biogeochemical feedbacks that explain the enigmatic Neoproterozoic carbon isotope record, according to numerical model simulations.

Regular oscillations in early Triassic ocean chemistry are explored in a box model. Periodic fluctuations in C and U isotopes are attributed to internal feedbacks in the coupled carbon-phosphorus-oxygen system after the end Permian mass extinction.

It is unclear why atmospheric O₂ remained at low levels for >1.5 billion years following the Great Oxidation Event. Here, the authors show that tectonic recycling of previously accumulated sedimentary organic carbon, and oxygen sensitivity of its oxidative weathering stabilized O₂at ∼1–10% of present levels.

The Neoproterozoic Snowball Earth glaciations were separated by tens of millions of years, although models suggest glacial inception should occur within millions. Numerical modelling suggests that the delay could be explained by inherent limits on silicate weathering rates controlled by the availability of fresh rock.

Although fluctuations in annual temperature have shown substantial geographical variation over the past few decades, which may be more difficult for society to adapt to than altered mean conditions, the time-evolving standard deviation of globally averaged temperature anomalies reveals that there has been little change.

Although the correlation between greenhouse gases and temperature is well documented, it is difficult to show causality from the data. This study uses insight from dynamical systems theory to show that internal Earth system mechanisms largely control climate dynamics, rather than orbital forcing, and temperature does have a reinforcing feedback on greenhouse-gas concentrations.

Latitudinal ecosystem boundaries in the global upper ocean may be driven by many factors. Here the authors investigate pole-to-pole eukaryotic phytoplankton metatranscriptomes, gene co-expression networks, and beta diversity, finding that geographic patterns are best explained by temperature gradients.

The long duration of the Middle Eocene Climatic Optimum, compared with other transient Eocene warming events, can be explained by an increase in clays forming from the weathering of silicate minerals, according to lithium isotope records of marine carbonates.

The expansion of oceanic anoxia during the Paleocene Eocene Thermal Maximum has important implications for faunal turnover patterns and global biogeochemical cycles. Here the authors use uranium isotopes and a biogeochemical model to suggest that the areal expansion of anoxia must have been limited to 10-fold.

The ability to predict a potential collapse of the Atlantic Meridional Overturning Circulation is widely desired, but problematic. Here, using a fully coupled atmosphere-ocean general circulation mode, the authors show that early warning signs can be detected 250 years in advance.

International climate policy needs to induce a socioeconomic tipping to a low or no-carbon economy if we are to avoid climate change tipping points.

Land-based mitigation for meeting the Paris climate target must consider the carbon cycle impacts of land-use change. Here the authors show that when bioenergy crops replace high carbon content ecosystems, forest-based mitigation could be more effective for CO₂ removal than bioenergy crops with carbon capture and storage.

Geochemical analyses and climate modelling suggest that 2.5 billion years ago much of the nitrogen now stored in the solid Earth was in the atmosphere, and that the higher atmospheric nitrogen levels would have increased the efficacy of greenhouse gases, thus warming the Earth.

Bivalves reveal that the subpolar North Atlantic destabilised and shows signs of having crossed a tipping point during the transition into the Little Ice Age.

The extent to which the onset of bioturbation affected global biogeochemistry during the Palaeozoic remains unclear. Here, the authors integrate bioturbation into the COPSE model, compare output with geochemical proxies, and suggest shallow burrowing contributed to a global low oxygen state during the early Cambrian.

Despite dramatic changes in carbon sinks, severe Snowball Earth glaciations have not occurred since the Cryogenian. Here, via the measurement of global subduction zone lengths and carbon cycle modelling, the authors show that a two fold increase in volcanic CO₂ input likely thwarted global glaciation.

The Amazon rainforest is increasingly under pressure from climate change and deforestation. The resilience of three-quarters of the forest, particularly in drier areas or close to human activity, has been decreasing since the 2000s, indicating that the system may be approaching a tipping point.

The GEOCARBSULF model provides the most detailed reconstructions of Phanerozoic O₂, but its predictions are not supported by geochemical data. Here, a GEOCARBSULF model rebuilt from first principles, with the addition of an amended sulphur cycle and the latest isotope records, supports a Paleozoic Oxygenation Event.

A review of observation-based evidence suggests that four interconnected Earth system tipping elements have moved towards their critical thresholds, highlighting the need for better monitoring and increased mitigation efforts.

The Late Ordovician period, ending 444 million years ago, was marked by the onset of glaciations. The expansion of non-vascular land plants accelerated chemical weathering and may have drawn down enough atmospheric carbon dioxide to trigger the growth of ice sheets.

The environmental implications of meeting the needs of the poorest are under debate. By showing substantial inequalities in natural resource claims and responsibility for ecological damage globally, this study estimates and discusses the impacts of achieving just access on the Earth system.