TY - JOUR
T1 - Inflated Uncertainty in Multimodel‐Based Regional Climate Projections
AU - Madsen, Marianne Sloth
AU - Langen, Peter L.
AU - Boberg, Fredrik
AU - Christensen, Jens Hesselbjerg
N1 - 2017/11/23
PY - 2017/11/28
Y1 - 2017/11/28
N2 - Multimodel ensembles are widely analyzed to estimate the range of future regional climate change projections. For an ensemble of climate models, the result is often portrayed by showing maps of the geographical distribution of the multimodel mean results and associated uncertainties represented by model spread at the grid point scale. Here we use a set of CMIP5 models to show that presenting statistics this way results in an overestimation of the projected range leading to physically implausible patterns of change on global but also on regional scales. We point out that similar inconsistencies occur in impact analyses relying on multimodel information extracted using statistics at the regional scale, for example, when a subset of CMIP models is selected to represent regional model spread. Consequently, the risk of unwanted impacts may be overestimated at larger scales as climate change impacts will never be realized as the worst (or best) case everywhere.
AB - Multimodel ensembles are widely analyzed to estimate the range of future regional climate change projections. For an ensemble of climate models, the result is often portrayed by showing maps of the geographical distribution of the multimodel mean results and associated uncertainties represented by model spread at the grid point scale. Here we use a set of CMIP5 models to show that presenting statistics this way results in an overestimation of the projected range leading to physically implausible patterns of change on global but also on regional scales. We point out that similar inconsistencies occur in impact analyses relying on multimodel information extracted using statistics at the regional scale, for example, when a subset of CMIP models is selected to represent regional model spread. Consequently, the risk of unwanted impacts may be overestimated at larger scales as climate change impacts will never be realized as the worst (or best) case everywhere.
KW - regional climate uncertainty multimodel projections
U2 - 10.1002/2017GL075627
DO - 10.1002/2017GL075627
M3 - Journal article
C2 - 29398736
SN - 0094-8276
VL - 44
SP - 606
EP - 613
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 22
ER -