Exceeding 1.5°C global warming could trigger multiple climate tipping points

Science, Journal Year: 2022, Volume and Issue: 377(6611)

Published: Sept. 8, 2022

Climate tipping points occur when change in a part of the climate system becomes self-perpetuating beyond warming threshold, leading to substantial Earth impacts. Synthesizing paleoclimate, observational, and model-based studies, we provide revised shortlist global "core" elements regional "impact" their temperature thresholds. Current ~1.1°C above preindustrial temperatures already lies within lower end some point uncertainty ranges. Several may be triggered Paris Agreement range 1.5 <2°C warming, with many more likely at 2 3°C expected on current policy trajectories. This strengthens evidence base for urgent action mitigate develop improved risk assessment, early warning capability, adaptation strategies.

Language: Английский

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Coral‐bleaching responses to climate change across biological scales

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(14), P. 4229 - 4250

Published: April 27, 2022

Abstract The global impacts of climate change are evident in every marine ecosystem. On coral reefs, mass bleaching and mortality have emerged as ubiquitous responses to ocean warming, yet one the greatest challenges this epiphenomenon is linking information across scientific disciplines spatial temporal scales. Here we review some seminal recent coral‐bleaching discoveries from an ecological, physiological, molecular perspective. We also evaluate which data processes can improve predictive models provide a conceptual framework that integrates measurements biological Taking integrative approach scales, using for example hierarchical estimate major coral‐reef processes, will not only rapidly advance science but necessary guide decision‐making conservation efforts. To conserve encourage implementing mesoscale sanctuaries (thousands km 2 ) transcend national boundaries. Such networks protected reefs reef connectivity, through larval dispersal transverse thermal environments, genotypic repositories may become essential units selection environmentally diverse locations. Together, multinational be best chance corals persist change, while humanity struggles reduce emissions greenhouse gases net zero.

Language: Английский

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Impacts of Climate Change on Marine Foundation Species

Annual Review of Marine Science, Journal Year: 2023, Volume and Issue: 16(1), P. 247 - 282

Published: Sept. 8, 2023

Marine foundation species are the biotic basis for many of world's coastal ecosystems, providing structural habitat, food, and protection myriad plants animals as well ecosystem services. However, climate change poses a significant threat to ecosystems they support. We review impacts on common marine species, including corals, kelps, seagrasses, salt marsh plants, mangroves, bivalves. It is evident that have already been severely impacted by several drivers, often through interactive effects with other human stressors, such pollution, overfishing, development. Despite considerable variation in geographical, environmental, ecological contexts, direct indirect gradual warming subsequent heatwaves emerged most pervasive drivers observed impact potent across all but from sea level rise, ocean acidification, increased storminess expected increase. Documented include changes genetic structures, physiology, abundance, distribution themselves their interactions flow-on associated communities, biodiversity, functioning. discuss strategies support into Anthropocene, order increase resilience ensure persistence services provide.

Language: Английский

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Mechanisms and Impacts of Earth System Tipping Elements

Reviews of Geophysics, Journal Year: 2023, Volume and Issue: 61(1)

Published: Feb. 16, 2023

Abstract Tipping elements are components of the Earth system which may respond nonlinearly to anthropogenic climate change by transitioning toward substantially different long‐term states upon passing key thresholds or “tipping points.” In some cases, such changes could produce additional greenhouse gas emissions radiative forcing that compound global warming. Improved understanding tipping is important for predicting future risks and their impacts. Here we review mechanisms, predictions, impacts, knowledge gaps associated with 10 notable proposed be elements. We evaluate approaching critical whether shifts manifest rapidly over longer timescales. Some have a higher risk crossing points under middle‐of‐the‐road pathways will possibly affect major ecosystems, patterns, and/or carbon cycling within 21st century. However, literature assessing scenarios indicates strong potential reduce impacts many through mitigation. The studies synthesized in our suggest most do not possess abrupt years, exhibit behavior, rather responding more predictably directly magnitude forcing. Nevertheless, uncertainties remain elements, highlighting an acute need further research modeling better constrain risks.

Language: Английский

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Systematic review of the uncertainty of coral reef futures under climate change

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: March 12, 2024

Abstract Climate change impact syntheses, such as those by the Intergovernmental Panel on Change, consistently assert that limiting global warming to 1.5 °C is unlikely safeguard most of world’s coral reefs. This prognosis primarily based a small subset available models apply similar ‘excess heat’ threshold methodologies. Our systematic review 79 articles projecting reef responses climate revealed five main methods. ‘Excess constituted one third (32%) all studies but attracted disproportionate share (68%) citations in field. Most methods relied deterministic cause-and-effect rules rather than probabilistic relationships, impeding field’s ability estimate uncertainty. To synthesize projections, we aimed identify with comparable outputs. However, divergent choices model outputs and scenarios limited analysis fraction studies. We found substantial discrepancies projected impacts, indicating serving basis for syntheses may project more severe consequences other Drawing insights from fields, propose incorporate uncertainty into modeling approaches multi-model ensemble approach generating projections futures.

Language: Английский

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Highest ocean heat in four centuries places Great Barrier Reef in danger

Nature, Journal Year: 2024, Volume and Issue: 632(8024), P. 320 - 326

Published: Aug. 7, 2024

Mass coral bleaching on the Great Barrier Reef (GBR) in Australia between 2016 and 2024 was driven by high sea surface temperatures (SST)

Language: Английский

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Oceanic differences in coral-bleaching responses to marine heatwaves

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 871, P. 162113 - 162113

Published: Feb. 9, 2023

Anomalously high ocean temperatures have increased in frequency, intensity, and duration over the last several decades because of greenhouse gas emissions that cause global warming marine heatwaves. Reef-building corals are sensitive to such temperature anomalies commonly lead coral bleaching, mortality, changes community structure. Yet, despite these overarching effects, there geographical differences thermal regimes, evolutionary histories, past disturbances may different bleaching responses within among oceans. Here we examined overall Atlantic, Indian, Pacific Oceans, using both a spatially explicit Bayesian mixed-effects model deep-learning neural-network model. We used 40-year dataset encompassing 23,288 coral-reef surveys at 11,058 sites 88 countries, from 1980 2020. Focusing on ocean-wide assessed relationships between percentage bleached temperature-related metrics alongside suite environmental variables. found while sea-surface were consistently, strongly, related all oceans, clear most For instance, was an increase with depth Atlantic Ocean whereas opposite observed Indian Ocean, no trend could be seen Ocean. The standard deviation thermal-stress negatively but not Globally, has progressively occurred higher four although, again, three Together, patterns highlight historical circumstances oceanographic conditions play central role contemporary coral-bleaching responses.

Language: Английский

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Emergent increase in coral thermal tolerance reduces mass bleaching under climate change

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Aug. 22, 2023

Abstract Recurrent mass bleaching events threaten the future of coral reefs. To persist under climate change, corals will need to endure progressively more intense and frequent marine heatwaves, yet it remains unknown whether their thermal tolerance can keep pace with warming. Here, we reveal an emergent increase in assemblages at a rate 0.1 °C/decade for remote Pacific reef system. This led less severe impacts than would have been predicted otherwise, indicating adaptation, acclimatisation or shifts community structure. Using projections, show that if continues rise over coming century most-likely historic rate, substantial reductions trajectories are possible. High-frequency be fully mitigated some reefs low-to-middle emissions scenarios, only delayed high scenarios. Collectively, our results indicate potential ecological resilience but still highlight reducing carbon line Paris Agreement commitments preserve

Language: Английский

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Corals at the edge of environmental limits: A new conceptual framework to re-define marginal and extreme coral communities

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 884, P. 163688 - 163688

Published: April 25, 2023

The worldwide decline of coral reefs has renewed interest in communities at the edge environmental limits because they have potential to serve as resilience hotspots and climate change refugia, can provide insights into how might function future ocean conditions. These are often referred marginal or extreme but few definitions exist usage these terms therefore been inconsistent. This creates significant challenges for categorising poorly studied synthesising data across locations. Furthermore, this impedes our understanding persist their lessons reef survival. Here, we propose that related distinct a novel conceptual framework redefine them. Specifically, define extremeness solely based on conditions (i.e., large deviations from optimal mean and/or variance) marginality ecological criteria altered community composition ecosystem functioning). joint independent assessment is critical avoid common pitfalls where existing outside presumed development automatically considered inferior more traditional settings. We further evaluate differential natural laboratories, discuss strategies conservation management well priorities research. Our new classification provides an important tool improve corals leverage knowledge optimise conservation, restoration rapidly changing ocean.

Language: Английский

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Mesophotic coral bleaching associated with changes in thermocline depth

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 16, 2023

As global temperatures continue to rise, shallow coral reef bleaching has become more intense and widespread. Mesophotic ecosystems reside in deeper (30-150 m), cooler water were thought offer a refuge shallow-water reefs. Studies now show that mesophotic instead have limited connectivity with corals but host diverse endemic communities. Given their extensive distribution high biodiversity, understanding susceptibility warming oceans is imperative. In this multidisciplinary study of an atoll the Chagos Archipelago central Indian Ocean, we evidence at 90 m, despite absence bleaching. We also was associated sustained thermocline deepening driven by Ocean Dipole, which might be further enhanced internal waves whose influence varied sub-atoll scale. Our results demonstrate potential vulnerability thermal stress highlight need for oceanographic knowledge predict heterogeneity.

Language: Английский

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