Prof. Sandy Harrison is the lead author on a new paper published in Nature Climate Change last week on 'Implications of evaluation of CMIP5 palaeosimulations for climate projections.'
Sandy and co-authors have summarised evaluations of palaeosimulations undertaken by members of the Palaeoclimate Modelling Intercomparison (PMIP) as part of the Coupled Model Intercomparison Project. The paper focuses on features of the climate that are characteristic of future projections and can be tested using past climate states.
Evaluations carried out by PMIP and described in this paper suggest that we can have confidence in the general trajectory and large-scale patterns shown by future projections. This includes the difference in warming of the land versus the ocean, and of the higher latitudes versus the tropics, and how precipitation changes as temperature changes. However, these evaluations indicate that we should exercise extreme caution about the magnitude (and sometimes even the sign) of regional climate changes when making planning decisions. For example, the models predict an increase in the monsoons both in the future and the mid-Holocene (MH) but the MH evaluation indicates that the models underestimate the change in precipitation in northern Africa by at least 50%. Models also predict an increase in aridity in the mid-continents in both the future and the MH. The MH predictions for Eurasia are wrong – palaeoenvironmental data show that this region was in fact wetter and cooler than today – and this raises serious concerns about the future projections for the region.
You can also read about this further on the blog by co-authors Dr Julia Hargreaves and Dr James Annan - at blueskiesresearch.
Sandy and co-authors have summarised evaluations of palaeosimulations undertaken by members of the Palaeoclimate Modelling Intercomparison (PMIP) as part of the Coupled Model Intercomparison Project. The paper focuses on features of the climate that are characteristic of future projections and can be tested using past climate states.
Evaluations carried out by PMIP and described in this paper suggest that we can have confidence in the general trajectory and large-scale patterns shown by future projections. This includes the difference in warming of the land versus the ocean, and of the higher latitudes versus the tropics, and how precipitation changes as temperature changes. However, these evaluations indicate that we should exercise extreme caution about the magnitude (and sometimes even the sign) of regional climate changes when making planning decisions. For example, the models predict an increase in the monsoons both in the future and the mid-Holocene (MH) but the MH evaluation indicates that the models underestimate the change in precipitation in northern Africa by at least 50%. Models also predict an increase in aridity in the mid-continents in both the future and the MH. The MH predictions for Eurasia are wrong – palaeoenvironmental data show that this region was in fact wetter and cooler than today – and this raises serious concerns about the future projections for the region.
You can also read about this further on the blog by co-authors Dr Julia Hargreaves and Dr James Annan - at blueskiesresearch.