Biogeographic climate sensitivity controls Earth system response to large igneous province carbon degassing

Science, Journal Year: 2024, Volume and Issue: 385(6709), P. 661 - 666

Published: Aug. 8, 2024

Periods of large igneous province (LIP) magmatism have shaped Earth's biological and climatic history, causing major shifts reorganizations. The vegetation response to LIP-induced perturbations may affect the efficiency carbon-climate regulation system post-LIP climate evolution. Using an eco-evolutionary model, we demonstrate here that vegetation's adaptation capacity, through evolution geographic dispersal, is a determinant severity longevity hyperthermals can promote emergence new steady state. Proxy-based temperature reconstructions Permian-Triassic, Triassic-Jurassic, Paleocene-Eocene match modeled trajectories bioclimatic disturbance recovery. We conclude dynamics shape multimillion-year Earth sudden carbon degassing global warming episodes.

Language: Английский

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Converged ensemble simulations of climate: possible trends in total solar irradiance cannot explain global warming alone

Frontiers in Earth Science, Journal Year: 2024, Volume and Issue: 12

Published: Aug. 6, 2024

We address the hypothetical question of whether an increasing total solar irradiance (TSI) trend, without anthropogenic contributions, could be sufficient to explain ongoing global warming. To this end, intermediate-complexity climate model PlaSim is used. consider internal variability, we present a set ensemble simulations, with different forcing histories in TSI and CO 2 concentration, that have converged sufficiently tightly relevant probability distributions provide satisfactory bound on any spurious trend possibly arising from sampling bias; similar bounds other unforced contributions mean trends are also estimated. A key point consideration, among histories, steepest still consistent observations according recent study; thereby, essentially revisit corresponding reconstructions, more than 20 years after their last modeling-based evaluation, by improving analysis through taking care all possible sources error or uncertainty incorporating data become available since then. Without change our (i.e., upper actual trends) found insufficient produce outcomes compatible observational record surface temperature (GMST) nonnegligible probability. formalize statement for quantifiers GMST evaluating over ensemble, speculate hypothesis about exclusive role remains implausible even beyond particular setup. At same time, if constant TSI, concentration applied as forcing, simulation results recorded match well. While currently need leave precise attribution open, conclude pointing out warming alone made plausible only bias land-based instrumental measurements were rapidly commonly estimated; assessment latter possibility scope study, well addressing mechanisms effect TSI.

Language: Английский

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Centennial‐Scale Variability of the Atlantic Meridional Overturning Circulation in CMIP6 Models Shaped by Arctic–North Atlantic Interactions and Sea Ice Biases

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(20)

Published: Oct. 28, 2024

Abstract Climate variability on centennial timescales has often been linked to internal of the Atlantic Meridional Overturning Circulation (AMOC). However, due scarceness suitable paleoclimate proxies and long climate model simulations, large uncertainties remain magnitude physical mechanisms driving centennial‐scale AMOC variability. For these reasons, we perform a systematic multi‐model comparison in pre‐industrial control simulations state‐of‐the‐art global models. Six out nine models this study exhibit statistically significant mode Our results show that freshwater exchanges between Arctic Ocean North provide plausible mechanism subset models, can be amplified by ocean–sea ice feedbacks Labrador Sea. The amplifying is sea cover biases, which could an observational constraint for

Language: Английский

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Detecting and Attributing Change in Climate and Complex Systems: Foundations, Green’s Functions, and Nonlinear Fingerprints

Physical Review Letters, Journal Year: 2024, Volume and Issue: 133(24)

Published: Dec. 9, 2024

Detection and attribution (DA) studies are cornerstones of climate science, providing crucial evidence for policy decisions. Their goal is to link observed change patterns anthropogenic natural drivers via the optimal fingerprinting method (OFM). We show that response theory nonequilibrium systems offers physical dynamical basis OFM, including concept causality used attribution. Our framework clarifies method's assumptions, advantages, potential weaknesses. use our perform DA prototypical experiments performed on an energy balance model a low-resolution coupled model. also explain underpinnings degenerate fingerprinting, which early warning indicators tipping points. Finally, we extend OFM nonlinear regime. analysis shows has broad applicability across diverse stochastic influenced by time-dependent forcings, with relevance ecosystems, quantitative social sciences, finance, among others.

Language: Английский

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Multi-centennial climate variability: Observational, theoretical and modeling studies

Chinese Science Bulletin (Chinese Version), Journal Year: 2023, Volume and Issue: unknown

Published: Feb. 1, 2023

长时间序列的代用资料表明地球气候系统存在着数百年时间尺度的气候变率，这种变率产生的原因及机制一直是困扰气候学家和考古学家的重大科学问题。从全新世中期直至工业革命之前，地球所受的外强迫变化较小，研究这一时期气候系统自然振荡非常重要。本文从观测、理论和模拟研究三个方面对多百年际气候变率的研究现状进行了详细梳理。我们期望能够通过创新性的理论和模式试验方法，勾画多百年际气候变率的空间模态，解密其时间尺度来源，揭示其内在运行机理，取得原创性成果，回答海洋动力学和气候动力学的一些基础科学问题。

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Simulating AMOC tipping driven by internal climate variability with a rare event algorithm.

Research Square (Research Square), Journal Year: 2023, Volume and Issue: unknown

Published: Aug. 8, 2023

Abstract This study investigates the possibility of Atlantic Meridional Overturning Circulation (AMOC) noise-induced tipping solely driven by internal climate variability without applying external forcing that alter radiative or North freshwater budget. We address this hypothesis with an innovative approach a rare event algorithm to ensemble simulations present-day intermediate complexity model. The successfully identifies trajectories leading abrupt AMOC slowdowns, which are unprecedented in 2000-year control run. Part these weakened states lead collapsed state evidence recovery on multi-centennial time scales. temperature and Northern Hemisphere jet stream responses internally-induced slowdowns show strong similarities those found externally forced state-of-the-art models. slowdown seems be initially Ekman transport due westerly wind stress anomalies subsequently amplified complete collapse oceanic convection Labrador Sea. These results demonstrate transitions purely model simulation but physically possible. Additionally, algorithms tool valuable general interest points since they introduce collecting large number events cannot sampled using traditional approaches. opens identifying mechanisms driving complex systems little a-priori knowledge is available.

Language: Английский

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Comment on npg-2023-7

Published: April 11, 2023

Abstract. The climate system as well ecosystems might undergo relatively sudden qualitative changes in the dynamics when environmental parameters or external forcings vary due to anthropogenic influences. study of these changes, called tipping phenomena, requires development new methodological approaches that allow modeling, analyzing, and predicting observed phenomena nature, especially concerning crisis its consequences. Here we briefly review mechanisms classical investigate more detail rate-dependent which occur non-autonomous systems characterized by multiple timescales. We focus on mechanism rate-induced caused basin boundary crossings. unravel this transition analyze, particular, role such crossings non-autonomous systems a parameter drift induces saddle-node bifurcation attractors saddle points emerge, including their basins attraction. Furthermore, detectability those bifurcations monitoring single trajectories state space find depending rate drift, be masked hidden they can detected only if critical is crossed. This analysis reveals quasi-stationary multistable are organizing centers global need much attention future studies.

Language: Английский

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Comment on egusphere-2023-2001

Published: Oct. 12, 2023

Abstract. It is now established that the increase in atmospheric CO₂ likely to cause a weakening, or perhaps collapse of Atlantic Meridional Overturning Circulation (AMOC). To investigate mechanisms this response CMIP5 models, Levang and Schmitt (2020) have estimated offline geostrophic streamfunction these models decomposed simulated changes into contribution caused by variations temperature salinity. They concluded under warming scenario, for most weakening AMOC fundamentally driven anomalies while freshwater forcing actually acts stabilize it. However, given both 3-D fields ocean salinity are expected respond at surface, it unclear what extent diagnostic informative about nature forcing. clarify question, we used Earth system Model Intermediate Complexity (EMIC) cGENIE, which equipped with C-GOLDSTEIN friction-geostrophic model. First, reproduced experiments simulating RCP8.5 scenario observed cGENIE behaves similarly majority considered (2020), dominated thermal structure ocean. Next, hysteresis associated (1) water hosing (2) decrease. In all experiments, initial appear be primarily distribution, distribution compensating only partly contribution. These also reveal limited sensitivity ocean's inventory. That diagnostics behave scenarios suggests output proposed mainly determined internal circulation, rather than applied Our results illustrate difficulty inferring any information from wind raise questions feasibility designing experiment could identify aspect (thermal haline) driving AMOC.

Language: Английский

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Comment on egusphere-2023-2001

Published: Oct. 12, 2023

Abstract. It is now established that the increase in atmospheric CO₂ likely to cause a weakening, or perhaps collapse of Atlantic Meridional Overturning Circulation (AMOC). To investigate mechanisms this response CMIP5 models, Levang and Schmitt (2020) have estimated offline geostrophic streamfunction these models decomposed simulated changes into contribution caused by variations temperature salinity. They concluded under warming scenario, for most weakening AMOC fundamentally driven anomalies while freshwater forcing actually acts stabilize it. However, given both 3-D fields ocean salinity are expected respond at surface, it unclear what extent diagnostic informative about nature forcing. clarify question, we used Earth system Model Intermediate Complexity (EMIC) cGENIE, which equipped with C-GOLDSTEIN friction-geostrophic model. First, reproduced experiments simulating RCP8.5 scenario observed cGENIE behaves similarly majority considered (2020), dominated thermal structure ocean. Next, hysteresis associated (1) water hosing (2) decrease. In all experiments, initial appear be primarily distribution, distribution compensating only partly contribution. These also reveal limited sensitivity ocean's inventory. That diagnostics behave scenarios suggests output proposed mainly determined internal circulation, rather than applied Our results illustrate difficulty inferring any information from wind raise questions feasibility designing experiment could identify aspect (thermal haline) driving AMOC.

Language: Английский

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Reply on AC2

Published: Dec. 19, 2023

Abstract. It is now established that the increase in atmospheric CO₂ likely to cause a weakening, or perhaps collapse of Atlantic Meridional Overturning Circulation (AMOC). To investigate mechanisms this response CMIP5 models, Levang and Schmitt (2020) have estimated offline geostrophic streamfunction these models decomposed simulated changes into contribution caused by variations temperature salinity. They concluded under warming scenario, for most weakening AMOC fundamentally driven anomalies while freshwater forcing actually acts stabilize it. However, given both 3-D fields ocean salinity are expected respond at surface, it unclear what extent diagnostic informative about nature forcing. clarify question, we used Earth system Model Intermediate Complexity (EMIC) cGENIE, which equipped with C-GOLDSTEIN friction-geostrophic model. First, reproduced experiments simulating RCP8.5 scenario observed cGENIE behaves similarly majority considered (2020), dominated thermal structure ocean. Next, hysteresis associated (1) water hosing (2) decrease. In all experiments, initial appear be primarily distribution, distribution compensating only partly contribution. These also reveal limited sensitivity ocean's inventory. That diagnostics behave scenarios suggests output proposed mainly determined internal circulation, rather than applied Our results illustrate difficulty inferring any information from wind raise questions feasibility designing experiment could identify aspect (thermal haline) driving AMOC.

Language: Английский

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