Downscaling and bias-correction contribute considerable uncertainty to local climate projections in CMIP6

npj Climate and Atmospheric Science, Journal Year: 2023, Volume and Issue: 6(1)

Published: Sept. 30, 2023

Abstract Efforts to diagnose the risks of a changing climate often rely on downscaled and bias-corrected information, making it important understand uncertainties potential biases this approach. Here, we perform variance decomposition partition uncertainty in global projections quantify relative importance downscaling bias-correction. We analyze simple metrics such as annual temperature precipitation averages, well several indices extremes. find that bias-correction contribute substantial local decision-relevant outcomes, though our results are strongly heterogeneous across space, time, metrics. Our can provide guidance impact modelers decision-makers regarding associated with when performing local-scale analyses, neglecting account for these may risk overconfidence full range possible futures.

Language: Английский

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Climate model Selection by Independence, Performance, and Spread (ClimSIPS v1.0.1) for regional applications

Geoscientific model development, Journal Year: 2023, Volume and Issue: 16(16), P. 4715 - 4747

Published: Aug. 23, 2023

Abstract. As the number of models in Coupled Model Intercomparison Project (CMIP) archives increase from generation to generation, there is a pressing need for guidance on how interpret and best use abundance newly available climate information. Users latest CMIP6 seeking draw conclusions about model agreement must contend with an “ensemble opportunity” containing similar that appear under different names. Those who used previous CMIP5 as basis downstream applications filter through hundreds new simulations find several suited their region, season, horizon interest. Here we present methods address both issues, dependence subselection, help users previously anchored navigate multi-model ensembles general. In Part I, refine definition based output, initially employed Climate Weighting by Independence Performance (ClimWIP), designate discrete families within CMIP6. We show increased presence bolsters upper mode ensemble's bimodal effective equilibrium sensitivity (ECS) distribution. Accounting mismatch representation between individual runs shifts ECS median 75th percentile down 0.43 ∘C, achieving better alignment CMIP5's II, approach subselection cost function minimization, Selection Independence, Performance, Spread (ClimSIPS). ClimSIPS selects sets CMIP relative importance user ascribes independence (as defined I), performance, ensemble spread projected outcome. demonstrate selecting three five European applications, evaluating performance observed mean outcome mid-century change surface air temperature precipitation. To accommodate cases, explore two ways represent multiple members ClimSIPS, first, and, second, member maximizes diversity overall. Because combinations are selected balances independence, priority, all subsets ternary contour “subselection triangles” guide recommendations further qualitative selection standards. represents novel framework select informed, efficient, transparent manner addresses growing simple tools, so those services can increasingly complex landscape.

Language: Английский

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Projections and uncertainties of winter windstorm damage in Europe in a changing climate

Natural hazards and earth system sciences, Journal Year: 2024, Volume and Issue: 24(5), P. 1555 - 1578

Published: May 3, 2024

Abstract. Winter windstorms are among the most significant natural hazards in Europe linked to fatalities and substantial damage. However, projections of windstorm impact under climate change highly uncertain. This study combines from 30 general circulation models participating Phase 6 Coupled Model Intercomparison Project (CMIP6) with risk assessment model CLIMADA obtain windstorm-induced damage over a changing climate. We conduct an uncertainty–sensitivity analysis find large uncertainties projected changes damage, uncertainty being dominant factor projections. investigate spatial patterns change-induced modifications increase northwestern northern central decrease rest Europe, agreement eastward extension North Atlantic storm track into Europe. combine all available ensemble-of-opportunity approach evidence for intensification future which return periods 100 years current conditions becomes 28 SSP585 scenarios. Our findings demonstrate importance CMIP6 emphasize increasing need mitigation due extreme weather future.

Language: Английский

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Understanding the influence of “hot” models in climate impact studies: a hydrological perspective

Hydrology and earth system sciences, Journal Year: 2023, Volume and Issue: 27(23), P. 4355 - 4367

Published: Dec. 11, 2023

Abstract. Efficient adaptation strategies to climate change require the estimation of future impacts and uncertainty surrounding this estimation. Over- or underestimating may lead maladaptation. Hydrological impact studies typically use a top-down approach in which multiple models are used assess related model structure sensitivity. Despite ongoing debate, modelers have embraced concept “model democracy”, each is considered equally fit. The newer Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations, with several showing sensitivity larger than that 5 (CMIP5) likely range based on past information understanding planetary physics, reignited democracy debate. Some suggested “hot” be removed from avoid skewing results toward unlikely futures. Indeed, inclusion these carries significant risk overestimating change. This large-sample study looks at removing hot projections streamflow over 3107 North American catchments. More precisely, variability mean, high, low flows evaluated using an ensemble 19 CMIP6 general circulation (GCMs), deemed their global equilibrium (ECS). show reduced 14 provides for Canada, Alaska, Southeast US, along Pacific coast. Elsewhere, has either no increased streamflow, indicating outlier do not necessarily provide regional impacts. These emphasize delicate nature selection, especially fitness metrics appropriate local assessments.

Language: Английский

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Screening CMIP6 models for Chile based on past performance and code genealogy

Climatic Change, Journal Year: 2024, Volume and Issue: 177(6)

Published: May 23, 2024

Language: Английский

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Emergent Constrained Projections of Mean and Extreme Warming in China

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(20)

Published: Oct. 14, 2023

Abstract Reliable regional temperature projections including heat extremes are essential for climate change adaptation and mitigation. Taking China as an example, simple averages from Coupled Model Intercomparison Project Phase 6 (CMIP6) models project high warming due to sampling many sensitivities in the ensemble. Here, we develop emergent constraint (EC) framework obtain constrained mean daily maximum (TXx) over by using observed global local residual warming. The annual TXx (2.33°C [1.61–3.05°C] 2.31°C [1.21–2.99°C]) 0.65°C [0.04–1.76°C] 0.63°C [–0.50–2.39°C], respectively, lower than raw (2.98°C [1.85–4.22°C] 2.94°C [2.04–4.39°C]) 2080–2099 under intermediate‐emission scenario. Approximately half model uncertainty is reduced after constraint. land area (population) experiencing our metric 78% (85%) of projections. Our results imply a impact extreme implied current CMIP6

Language: Английский

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Reversal of the impact chain for actionable climate information

Nature Geoscience, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 3, 2025

Language: Английский

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A rapid-application emissions-to-impacts tool for scenario assessment: Probabilistic Regional Impacts from Model patterns and Emissions (PRIME)

Geoscientific model development, Journal Year: 2025, Volume and Issue: 18(5), P. 1785 - 1808

Published: March 14, 2025

Abstract. Climate policies evolve quickly, and new scenarios designed around these are used to illustrate how they impact global mean temperatures using simple climate models (or emulators). Simple extremely efficient, although some can only provide estimates of metrics such as surface temperature, CO2 concentration effective radiative forcing. Within the Intergovernmental Panel on Change (IPCC) framework, understanding regional impacts that include most recent science is needed allow targeted policy decisions be made quickly. To address this, we present PRIME (Probabilistic Regional Impacts from Model patterns Emissions), a flexible probabilistic framework which aims an efficient mechanism run without significant overheads larger, more complex Earth system (ESMs). provides capability features ESM projections, ensemble simulations multi-centennial timescales analyses many key variables relevant important for assessments. We use model temperature response emissions scenarios. These estimated scale monthly large number CMIP6 ESMs. inputs “weather generator” algorithm land model. The thus generates end-to-end estimate test known in form shared socioeconomic pathways (SSPs), demonstrate our reproduces responses show results range scenarios: SSP5–8.5 high-emissions scenario was define patterns, SSP1–2.6, mitigation with low emissions, SSP5–3.4-OS, overshoot scenario, were verification data. correctly represents (and spread) scenarios, gives us confidence simulation will useful rapidly providing spatially resolved information novel thereby substantially reducing time between being released availability information.

Language: Английский

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Localized climate change impacts on tourism businesses

Annals of Tourism Research Empirical Insights, Journal Year: 2025, Volume and Issue: 6(1), P. 100176 - 100176

Published: April 8, 2025

Language: Английский

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On the role of moist and dry processes in atmospheric blocking biases in the Euro-Atlantic region in CMIP6

Weather and Climate Dynamics, Journal Year: 2025, Volume and Issue: 6(2), P. 471 - 487

Published: April 22, 2025

Abstract. Synoptic- and large-scale features of atmospheric flow such as extratropical cyclones, Rossby wave packets, blocking modulate mid-latitude weather climate. However, several studies have shown strong biases in the frequency location these state-of-the-art global climate models. One notable persistent bias is an underestimation Euro-Atlantic region. In this study, we validate representation synoptic- North Atlantic eight models Coupled Model Intercomparison Project Phase 6 (CMIP6), taking ERA5 reanalysis a reference. Validation includes blocking, storm tracks, eddy heat moisture fluxes, warm conveyor belts (WCBs). The selected CMIP6 underestimate over eastern Europe winter (December to February) by up 80 %. result from combined at different spatial temporal scales described following. First, define background most frequent value daily time series meridional gradient geopotential height 500 hPa. models, strongest latitudinal gradients are shifted equatorward basin. This shift favours more zonal stronger winds south climatological jet. differences affect breaking onset persistence, illustrated analysing eddies We find that accelerates mean exit region jet, indicated reduction divergence E vectors. leads less diffluent east and, thus, favourable for formation. Second, negative WCB outflow Atlantic. Reduced indicates weaker transport low potential vorticity (PV) lower upper troposphere moist diabatic processes consequently downstream ridge amplification therefore, contributions blocking. can be linked levels inflow area western Thus, misrepresentation contributes biases. Accordingly, improved next generation could improve representation.

Language: Английский

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