A Scaling Approach to Probabilistic Assessment of Regional Climate Change

A new approach to probabilistic projections of regional climate change is introduced. It builds on the already established quasi-linear relation between global-mean temperature and regional climate change found in atmosphere–ocean general circulation models (AOGCMs). The new approach simultaneously 1) takes correlations between temperature- and precipitation-related uncertainty distributions into account, 2) enables the inclusion of predictors other than global-mean temperature, and 3) checks for the interscenario and interrun variability of the scaling relationships. This study tests the effectiveness of SOx and black carbon emissions and greenhouse gas forcings as additional predictors of precipitation changes. The future precipitation response is found to deviate substantially from the linear relationship with global-mean temperature change in some regions; thereby, the two main limitations of a simple linear scaling approach, namely having to rely on exogenous aerosol experiments (or ignoring their regional effect), and ignoring changes in scaling coefficients when approaching equilibrium conditions, are addressed. The additional predictors can markedly improve the emulation of AOGCM simulations. In some regions, variations in hydrological sensitivity (the percentage change of precipitation per degree of warming) across different scenarios can be reduced by more than 50%. Coupled to probabilistic projections of global-mean temperatures and greenhouse gas forcings, bidimensional distributions of regional temperature and precipitation changes accounting for multiple uncertainties are derived. Based on 20 Fourth Assessment Report AOGCMs (AR4 AOGCMs), probabilistic projections are provided for two representative concentration pathway (RCP) scenarios and 31 world regions (online database at www.pik-potsdam.de/primap/regional_temp_and_precip ). As an example application of the projections for climate adaptation and vulnerability studies, future changes in the surface mass balance of the Greenland Ice Sheet are computed.

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A new approach for assessing climate change impacts in ecotron experiments

10.5194/bg-2019-267 ◽

2019 ◽

Author(s):

Inne Vanderkelen ◽

Jakob Zschleischler ◽

Lukas Gudmundsson ◽

Klaus Keuler ◽

Francois Rineau ◽

...

Keyword(s):

Climate Change ◽

Regional Climate Model ◽

Climate Model ◽

Global Climate Model ◽

Regional Climate ◽

Climate Change Impacts ◽

New Approach ◽

Global Mean Temperature ◽

Mean Temperature ◽

Global Mean

Abstract. Ecotron facilities allow accurate control of many environmental variables coupled with extensive monitoring of ecosystem processes. They therefore require multivariate perturbation of climate variables, close to what is observed in the field and projections for the future, preserving the co-variances between variables and the projected changes in variability. Here we present a new experimental design for studying climate change impacts on terrestrial ecosystems and apply it to the UHasselt Ecotron Experiment. The new methodology consists of generating climate forcing along a gradient representative of increasingly high global mean temperature anomalies and uses data derived from the best available regional climate model (RCM) projection. We first identified the best performing regional climate model (RCM) simulation for the ecotron site from the Coordinated Regional Downscaling Experiment in the European Domain (EURO-CORDEX) ensemble with a 0.11° (12.5 km) resolution based on two criteria: (i) highest skill of the simulations compared to observations from a nearby weather station and (ii) representativeness of the multi-model mean in future projections. Our results reveal that no single RCM simulation has the best score for all possible combinations of the four meteorological variables and evaluation metrics considered. Out of the six best performing simulations, we selected the simulation with the lowest bias for precipitation (CCLM4-8-17/EC-EARTH), as this variable is key to ecosystem functioning and model simulations deviated the most for this variable, with values ranging up to double the observed values. The time window is subsequently selected from the RCM projection for each ecotron unit based on the global mean temperature of the driving Global Climate Model (GCM). The ecotron units are forced with 3-hourly output from the RCM projections of the five-year period spanning the year in which the global mean temperature crosses the predefined values. With the new approach, Ecotron facilities become able to assess ecosystem responses on changing climatic conditions, while accounting for the co-variation between climatic variables and their projection in variability, well representing possible compound events. The gradient approach will allow to identify possible threshold and tipping points.

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Review of "European climate change at global mean temperature increases of 1.5 and 2°C above pre-industrial conditions as simulated by the EURO-CORDEX regional climate models"

10.5194/esd-2017-104-rc1 ◽

2017 ◽

Author(s):

Anonymous

Keyword(s):

Climate Change ◽

Climate Models ◽

Regional Climate ◽

Regional Climate Models ◽

Global Mean Temperature ◽

European Climate ◽

Mean Temperature ◽

Global Mean

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A Simple Equation for Regional Climate Change and Associated Uncertainty

Journal of Climate ◽

10.1175/2007jcli1763.1 ◽

2008 ◽

Vol 21 (7) ◽

pp. 1589-1604 ◽

Cited By ~ 23

Author(s):

Filippo Giorgi

Keyword(s):

Climate Change ◽

Global Climate ◽

Regional Climate ◽

Regional Climate Change ◽

First Century ◽

Temperature And Precipitation ◽

Regional Temperature ◽

Global Temperature Change ◽

Simple Equations ◽

Precipitation Changes

Abstract Simple equations are developed to express regional climate changes for the twenty-first century and associated uncertainty in terms of the global temperature change (GTC) without a dependence on the underlying emission pathways. The equations are applied to regional temperature and precipitation changes over different regions of the world, and relevant parameters are calculated using the latest multimodel ensemble of global climate change simulations. Examples are also shown of how to use the equations to develop probability density functions (PDFs) of regional climate change based on PDFs of GTC. The main advantage of these equations is that they can be used to estimate regional changes from GTC obtained either from simple and intermediate complexity models or from target CO2 stabilization concentrations.

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Two Approaches to Quantifying Uncertainty in Global Temperature Changes

Journal of Climate ◽

10.1175/jcli3895.1 ◽

2006 ◽

Vol 19 (19) ◽

pp. 4785-4796 ◽

Cited By ~ 52

Author(s):

Ana Lopez ◽

Claudia Tebaldi ◽

Mark New ◽

Dave Stainforth ◽

Myles Allen ◽

...

Keyword(s):

General Circulation ◽

Regional Climate ◽

Regional Climate Change ◽

General Circulation Models ◽

Temperature Changes ◽

Global Mean Temperature ◽

Statistical Approaches ◽

Quantifying Uncertainty ◽

Global Mean ◽

Probabilistic Projections

Abstract A Bayesian statistical model developed to produce probabilistic projections of regional climate change using observations and ensembles of general circulation models (GCMs) is applied to evaluate the probability distribution of global mean temperature change under different forcing scenarios. The results are compared to probabilistic projections obtained using optimal fingerprinting techniques that constrain GCM projections by observations. It is found that, due to the different assumptions underlying these statistical approaches, the predicted distributions differ significantly in particular in their uncertainty ranges. Results presented herein demonstrate that probabilistic projections of future climate are strongly dependent on the assumptions of the underlying methodologies.

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European climate change at global mean temperature increases of 1.5 and 2 °C above pre-industrial conditions as simulated by the EURO-CORDEX regional climate models

Earth System Dynamics ◽

10.5194/esd-9-459-2018 ◽

2018 ◽

Vol 9 (2) ◽

pp. 459-478 ◽

Cited By ~ 40

Author(s):

Erik Kjellström ◽

Grigory Nikulin ◽

Gustav Strandberg ◽

Ole Bøssing Christensen ◽

Daniela Jacob ◽

...

Keyword(s):

Climate Change ◽

Wind Speed ◽

Climate Models ◽

Regional Climate ◽

Surface Wind ◽

Near Surface ◽

The North ◽

Global Mean Temperature ◽

Mean Temperature ◽

Global Mean

Abstract. We investigate European regional climate change for time periods when the global mean temperature has increased by 1.5 and 2 °C compared to pre-industrial conditions. Results are based on regional downscaling of transient climate change simulations for the 21st century with global climate models (GCMs) from the fifth-phase Coupled Model Intercomparison Project (CMIP5). We use an ensemble of EURO-CORDEX high-resolution regional climate model (RCM) simulations undertaken at a computational grid of 12.5 km horizontal resolution covering Europe. The ensemble consists of a range of RCMs that have been used for downscaling different GCMs under the RCP8.5 forcing scenario. The results indicate considerable near-surface warming already at the lower 1.5 °C of warming. Regional warming exceeds that of the global mean in most parts of Europe, being the strongest in the northernmost parts of Europe in winter and in the southernmost parts of Europe together with parts of Scandinavia in summer. Changes in precipitation, which are less robust than the ones in temperature, include increases in the north and decreases in the south with a borderline that migrates from a northerly position in summer to a southerly one in winter. Some of these changes are already seen at 1.5 °C of warming but are larger and more robust at 2 °C. Changes in near-surface wind speed are associated with a large spread among individual ensemble members at both warming levels. Relatively large areas over the North Atlantic and some parts of the continent show decreasing wind speed while some ocean areas in the far north show increasing wind speed. The changes in temperature, precipitation and wind speed are shown to be modified by changes in mean sea level pressure, indicating a strong relationship with the large-scale circulation and its internal variability on decade-long timescales. By comparing to a larger ensemble of CMIP5 GCMs we find that the RCMs can alter the results, leading either to attenuation or amplification of the climate change signal in the underlying GCMs. We find that the RCMs tend to produce less warming and more precipitation (or less drying) in many areas in both winter and summer.

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European climate change at global mean temperature increases of 1.5 and 2 °C above pre-industrial conditions as simulated by the EURO-CORDEX regional climate models

10.5194/esd-2017-104 ◽

2017 ◽

Cited By ~ 1

Author(s):

Erik Kjellström ◽

Grigory Nikulin ◽

Gustav Strandberg ◽

Ole Bøssing Christensen ◽

Daniela Jacob ◽

...

Keyword(s):

Climate Change ◽

Wind Speed ◽

Climate Models ◽

Regional Climate ◽

Surface Wind ◽

Near Surface ◽

The North ◽

Global Mean Temperature ◽

Mean Temperature ◽

Global Mean

Abstract. We investigate European regional climate change for time periods when the global mean temperature has increased by respectively 1.5 °C and 2 °C compared to preindustrial conditions. Results are based on regional downscaling of transient climate change simulations for the 21st century with global climate models (GCMs) from the fifth phase Coupled Model Intercomparison Project (CMIP5). We use an ensemble of EURO-CORDEX high-resolution regional climate model (RCM) simulations undertaken at a computational grid of 12.5 km horizontal resolution covering Europe. The ensemble consists of a range of RCMs that have been used for downscaling different GCMs under different forcing scenarios. The results indicate considerable near-surface warming already at the lower 1.5 °C warming. Regional warming exceeds that of the global mean in most parts of Europe, strongest in northernmost parts of Europe in winter and in southernmost parts of Europe together with parts of Scandinavia in summer. Changes in precipitation, that are less robust than the ones in temperature, include increases in the north and decreases in the south with a borderline that migrates from a northerly position in summer to a southerly one in winter. Some of these changes are seen already at 1.5 °C warming but larger and more robust at 2 °C. Changes in near-surface wind speed are associated with a large spread between individual ensemble members at both warming levels. Relatively large areas over the North Atlantic and some parts of the continent shows decreasing wind speed while some ocean areas in the far north show increasing wind speed. The changes in temperature, precipitation and wind speed are shown to be modified by changes in mean sea level pressure indicating a strong relationship with the large-scale circulation and its internal variability on decade-long timescales. By comparing to a larger ensemble of CMIP5 GCMs we find that the RCMs can alter the results leading either to attenuation of amplification of the climate change signal in the underlying GCMs. We find that the RCMs tend to produce less warming and more precipitation (or less drying) in many areas in both winter and summer.

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An Assessment of Global Macroeconomic Impacts Caused by Sea Level Rise Using the Framework of Shared Socioeconomic Pathways and Representative Concentration Pathways

Sustainability ◽

10.3390/su12093737 ◽

2020 ◽

Vol 12 (9) ◽

pp. 3737

Author(s):

Osamu Nishiura ◽

Makoto Tamura ◽

Shinichiro Fujimori ◽

Kiyoshi Takahashi ◽

Junya Takakura ◽

...

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

Low Income ◽

Temperature Increase ◽

General Circulation ◽

Economic Losses ◽

Global Mean Temperature ◽

Mean Temperature ◽

Global Mean

Coastal areas provide important services and functions for social and economic activities. Damage due to sea level rise (SLR) is one of the serious problems anticipated and caused by climate change. In this study, we assess the global economic impact of inundation due to SLR by using a computable general equilibrium (CGE) model that incorporates detailed coastal damage information. The scenario analysis considers multiple general circulation models, socioeconomic assumptions, and stringency of climate change mitigation measures. We found that the global household consumption loss proportion will be 0.045%, with a range of 0.027−0.066%, in 2100. Socioeconomic assumptions cause a difference in the loss proportion of up to 0.035% without greenhouse gas (GHG) emissions mitigation, the so-called baseline scenarios. The range of the loss proportion among GHG emission scenarios is smaller than the differences among the socioeconomic assumptions. We also observed large regional variations and, in particular, the consumption losses in low-income countries are, relatively speaking, larger than those in high-income countries. These results indicate that, even if we succeed in stabilizing the global mean temperature increase below 2 °C, economic losses caused by SLR will inevitably happen to some extent, which may imply that keeping the global mean temperature increase below 1.5 °C would be worthwhile to consider.

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Changes in regional climate extremes as a function of global mean temperature: an interactive plotting framework

10.5194/gmd-2017-33 ◽

2017 ◽

Author(s):

Richard Wartenburger ◽

Martin Hirschi ◽

Markus G. Donat ◽

Peter Greve ◽

Andy J. Pitman ◽

...

Keyword(s):

Water Cycle ◽

Regional Climate ◽

Coupled Model ◽

Climate Extremes ◽

Global Mean Temperature ◽

Mean Temperature ◽

Intercomparison Project ◽

Projected Changes ◽

Regional Analyses ◽

Global Mean

Abstract. This article extends a previous study (Seneviratne et al., 2016) to provide regional analyses of changes in climate extremes as a function of projected changes in global mean temperature. We introduce the DROUGHT-HEAT Regional Climate Atlas, an interactive tool to analyse and display a range of well-established climate extremes and water-cycle indices and their changes as a function of global warming. These projections are based on simulations from the 5th phase of the Coupled Model Intercomparison Project (CMIP5). A selection of example results are presented here, but users can visualize specific indices of interest using the online tool. This implementation enables a direct assessment of regional climate changes associated with global temperature targets, such as the 2 degree and 1.5 degree limits agreed within the 2015 Paris Agreement.

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