In this seminar, the Prof. Chris was invited to give a speech titled as ” Characterizing Climate Change from Global to Regional Scales”.

During the talk, he first introduced the concept of uncertainty in climate change studies, in which there are both the natural uncertainty (Aleatoric uncertainty) due to the stochastic behavior of climate itself, and the epistemic uncertainty because of wrongly understanding the natural phenomenon and hence improper model design. Also there are internal uncertainty raised from the model itself and the choice of initial conditions.

In the second part, Prof. Chris talked about the climate change studies on global scale, where the focus is on the global mean temperature change and its response to the CO2 forcing scenarios (Representative Concentration Pathway). He also showed many results about climate uncertainty resulted from the different circulation models, and then nicely pointed out that when changing the focus of spatial scale, e.g. from global to hemisphere or zonal level, the uncertainty range might change, a possible explanation for the large uncertainty we commonly see in IPCC report.

The last part was devoted to the regional scale, in which people tend to study the climate change impact on certain region in response to the Sea Surface Temperature anomalies, through so called teleconnection affect. The method they are using now is called Global Teleconnection Operator approach, sort of linear regression model. By calibrating the parameters using projected SST anomalies and validating it against observed ones, one can demonstrate and understand how likely the change is going to happen at this region.

< click here to see the abstract of this seminar >

Key word: Climate change, Uncertainty, Global circulation model, Global Teleconnection Operator,