Ubiquity of human-induced changes in climate variability

Earth System Dynamics, Journal Year: 2021, Volume and Issue: 12(4), P. 1393 - 1411

Published: Dec. 9, 2021

Abstract. While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how variability responds to increasing anthropogenic perturbations. Thus far Earth system modeling efforts have primarily focused projected changes the sensitivity of specific modes variability, such as El Niño–Southern Oscillation. However, our knowledge forced in overall spectrum higher-order statistics is relatively limited. Here we present a new 100-member large ensemble projections conducted with Community System Model version 2 over 1850–2100 examine internal fluctuations greenhouse warming. Our unprecedented simulations reveal that considered broadly terms probability distribution, amplitude, frequency, phasing, patterns, are ubiquitous span wide range physical ecosystem variables across many spatial temporal scales. Greenhouse warming model alters variance spectra characterized by non-Gaussian distributions, rainfall, primary production, or fire occurrence. results important implications for efforts, resource management, seasonal predictions, assessing potential stressors terrestrial marine ecosystems.

Language: Английский

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CMIP6 Simulations With the CMCC Earth System Model (CMCC‐ESM2)

Journal of Advances in Modeling Earth Systems, Journal Year: 2022, Volume and Issue: 14(3)

Published: Feb. 11, 2022

Abstract This article introduces the second generation CMCC Earth System Model (CMCC‐ESM2) that extends a number of marine and terrestrial biogeochemical processes with respect to its CMIP5 predecessor. In particular, land biogeochemistry was extended wider set carbon pools plant functional types, along prognostic representation nitrogen cycle. The ecosystem reshaped toward an intermediate complexity lower trophic level interactions, including interactive benthic compartment new formulation heterotrophic bacterial population. Details are provided on model setup implementation for different experiments performed as contribution sixth phase Coupled Intercomparison Project. CMCC‐ESM2 shows equilibrium climate sensitivity 3.57°C transient response 1.97°C which close CMIP6 multi‐model averages. evaluation coupled climate‐carbon in historical period against available observational datasets show consistent both physical quantities. However, sink is found be weaker than current global estimates simulated primary production slightly below satellite‐based average over recent decades. Future projections coherently prominent warming northern hemisphere intensified precipitations at high latitudes. expected ranges variability oceanic pH oxygen, well soil storage, compare favorably those assessed from other models.

Language: Английский

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Large-scale features and evaluation of the PMIP4-CMIP6 <i>midHolocene</i> simulations

Climate of the past, Journal Year: 2020, Volume and Issue: 16(5), P. 1847 - 1872

Published: Oct. 1, 2020

Abstract. The mid-Holocene (6000 years ago) is a standard time period for the evaluation of simulated response global climate models using palaeoclimate reconstructions. latest simulations are entry card Palaeoclimate Model Intercomparison Project (PMIP4) component current phase Coupled (CMIP6) – hereafter referred to as PMIP4-CMIP6. Here we provide an initial analysis and results experiment mid-Holocene. We show that state-of-the-art produce changes broadly consistent with theory observations, including increased summer warming Northern Hemisphere associated shifts in tropical rainfall. Many features PMIP4-CMIP6 were present previous generation (PMIP3-CMIP5) simulations. ensemble has mean temperature change −0.3 K, which −0.2 K cooler than PMIP3-CMIP5 predominantly result prescription realistic greenhouse gas concentrations Biases magnitude sign regional responses identified PMIP3-CMIP5, such amplification northern African monsoon, precipitation over Europe, aridity mid-Eurasia, still Despite these issues, opportunity both quantitative derivation emergent constraints on hydrological cycle, feedback strength, potentially sensitivity.

Language: Английский

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An Overview of Ocean Climate Change Indicators: Sea Surface Temperature, Ocean Heat Content, Ocean pH, Dissolved Oxygen Concentration, Arctic Sea Ice Extent, Thickness and Volume, Sea Level and Strength of the AMOC (Atlantic Meridional Overturning Circulation)

Frontiers in Marine Science, Journal Year: 2021, Volume and Issue: 8

Published: Sept. 21, 2021

Global ocean physical and chemical trends are reviewed updated using seven key climate change indicators: (i) Sea Surface Temperature, (ii) Ocean Heat Content, (iii) pH, (iv) Dissolved Oxygen concentration (v) Arctic Ice extent, thickness, volume (vi) Level (vii) the strength of Atlantic Meridional Overturning Circulation (AMOC). The globally averaged surface temperature shows a mean warming trend 0.062 ± 0.013°C per decade over last 120 years (1900–2019). During (2010–2019) rate has accelerated to 0.280 0.068°C decade, 4.5 times higher than long term mean. Content in upper 2,000 m linear 0.35 0.08 Wm –2 period 1955–2019 (65 years). during is twice (0.70 0.07 ) record. Each six decades have been warmer previous one. pH declined on average by approximately 0.1 units (from 8.2 8.1) since industrial revolution (1770). By end this century (2100) projected decline additionally 0.1–0.4 depending RCP (Representative Concentration Pathway) SSP (Shared Socioeconomic Pathways) future scenario. time emergence signal varies from 8 15 for open sites, 16–41 coastal sites. dissolved oxygen levels decreased 4.8 petamoles or 2% 5 decades, with profound impacts local basin scale habitats. Regional varying due multiple processes impacting oxygen: solubility change, respiration changes, circulation changes multidecadal variability. sea ice extent declining −13.1% summer (September) −2.6% winter (March) 4 (1979–2020). combined thickness indicate that non-seasonal 75% 1979. level increased 1993–2019 (the altimetry era) at 3.15 0.3 mm year –1 experiencing an acceleration ∼ 0.084 (0.06–0.10) . (1900–2015; 115y) global (GMSL) rised 19 cm, near 40% GMSL rise taken place 1993 (22y). Independent proxies evolution (AMOC) AMOC its weakest several hundreds slowing down century. A final visual summary indicators recent provided.

Language: Английский

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Persistent Uncertainties in Ocean Net Primary Production Climate Change Projections at Regional Scales Raise Challenges for Assessing Impacts on Ecosystem Services

Frontiers in Climate, Journal Year: 2021, Volume and Issue: 3

Published: Nov. 25, 2021

Ocean net primary production (NPP) results from CO 2 fixation by marine phytoplankton, catalysing the transfer of organic matter and energy to ecosystems, supporting most food webs, fisheries as well stimulating ocean carbon sequestration. Thus, alterations NPP in response climate change, quantified Earth system model experiments conducted part 5th 6th Coupled Model Intercomparison Project (CMIP5 CMIP6) efforts, are expected alter key ecosystem services. Despite reductions inter-model variability since CMIP5, components CMIP6 models disagree roughly 2-fold magnitude spatial distribution contemporary era, due incomplete understanding insufficient observational constraints. Projections change absolute terms show large uncertainty CMIP6, notably North Atlantic Indo-Pacific regions, with latter explaining over two-thirds total uncertainty. While has previously been identified a hotspot for impacts on biodiversity fisheries, increased projections further exacerbates uncertainties risks ocean-dependent human communities. Drivers changes at regional scales integrate different physical biogeochemical factors that require more targeted mechanistic assessment future studies. Globally, projected which amplifies challenges associated management Notably, this occurred despite reduced rates historical period. Improved constraints drivers its would improve confidence changes. It is unlikely ensemble samples complete NPP, inclusion additional realism likely widen future, especially scales. This important consequences assessing impacts. Ultimately, we need an integrated framework considers how ecosystems respond not only but also non-climate drivers.

Language: Английский

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Zonally contrasting shifts of the tropical rain belt in response to climate change

Nature Climate Change, Journal Year: 2021, Volume and Issue: 11(2), P. 143 - 151

Published: Jan. 18, 2021

Language: Английский

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Sensitivity of the Atlantic Meridional Overturning Circulation to Model Resolution in CMIP6 HighResMIP Simulations and Implications for Future Changes

Journal of Advances in Modeling Earth Systems, Journal Year: 2020, Volume and Issue: 12(8)

Published: July 17, 2020

Abstract A multimodel, multiresolution ensemble using Coupled Model Intercomparison Project Phase 6 (CMIP6) High Resolution (HighResMIP) coupled experiments is used to assess the performance of key aspects North Atlantic circulation. The Meridional Overturning Circulation (AMOC), and related heat transport, tends become stronger as ocean model resolution enhanced, better agreeing with observations at 26.5°N. However, for most models circulation remains too shallow compared has a smaller temperature contrast between northward southward limbs AMOC. These biases cause transport be systematically low given overturning strength. higher‐resolution also tend have much deep mixing in subpolar gyre. In period 2015–2050 decline more rapidly models, which both mean state gyre contribution water formation. main part comes from Florida Current component Such large declines AMOC are not seen resolutions typically climate studies, suggesting an enhanced risk Northern Hemisphere change. only small number different included study.

Language: Английский

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Future climate change shaped by inter-model differences in Atlantic meridional overturning circulation response

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: June 16, 2021

In climate model simulations of future change, the Atlantic Meridional Overturning Circulation (AMOC) is projected to decline. However, impacts this decline, relative other changes, remain be identified. Here we address problem by analyzing 30 idealized abrupt-4xCO

Language: Английский

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The evolution of the North Atlantic Meridional Overturning Circulation since 1980

Nature Reviews Earth & Environment, Journal Year: 2022, Volume and Issue: 3(4), P. 241 - 254

Published: March 1, 2022

Language: Английский

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Natural variability has dominated Atlantic Meridional Overturning Circulation since 1900

Nature Climate Change, Journal Year: 2022, Volume and Issue: 12(5), P. 455 - 460

Published: April 25, 2022

Abstract There is debate about slowing of the Atlantic Meridional Overturning Circulation (AMOC), a key component global climate system. Some focus on sea surface temperature (SST) slightly cooling in parts subpolar North despite widespread ocean warming. SST influenced by AMOC, especially decadal timescales and beyond. The local could thus reflect AMOC diminishing heat transport, consistent with model responses to rising atmospheric greenhouse gas concentrations. Here we show from prevalence natural variability since 1900. This historical simulations for 1900–2014 predicting average 1 Sv at 30° N after 1980, which within range internal multidecadal derived models’ preindustrial control runs. These results highlight importance systematic sustained in-situ monitoring systems that can detect attribute high confidence an anthropogenic signal.

Language: Английский

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