How simulation can help predict the effects of pandemics and climate change

Professor Russell Cheng is an Emeritus Professor of Mathematical Sciences at the University of Southampton. Having been Professor of Operational Research and Head of the OR Group there from 1999 to 2007, in the School of Mathematics.

He obtained an MA and a Diploma in Mathematical Statistics from Cambridge University, and a PhD from University of Bath. He was previously Deputy Director of the Institute of Mathematics and Statistics and Head of Management Science at the University of Kent at Canterbury. He was Visiting Professor at the University of North Carolina (UNC) at Chapel Hill in the academic year 1985-6.

Russell is a former Fellow of the Royal Statistical Society, a Fellow of the Institute of Mathematics and Its Applications, and a past Chairman of the United Kingdom Simulation Society. He is a past Board Member of EUROSIM, the Federation of Simulation Societies in Europe.

As the author of over 140 publications on the Design and Analysis of Simulation Experiments, Non-standard Parametric Estimation, Computer Generated Graphics, Optimal Control of Industrial Processes, and Marine Simulation, Russell is wellknown and respected in the world of Operational Research.

He is currently a course lecturer at the UK National Taught Course Centre in Operational Research (NATCOR) which delivers nationwide residential courses to UK research students in OR and Management Science.

Professor Russell Cheng

At SW23 he provided a powerful and thought-provoking talk on how simulation can help predict the effects of pandemics and climate change via MultiWave skew-logistic processes. The parameters he input for his Covid simulation included the number of active cases at any given time, rate of increase of infection, rate of decrease of infection and location of infection.

He spoke of the use of a SEPIR model which focused on Susceptibles, Exposed, Pre-symptomatic, Infected (symptomatic) and Removed; the importance of fitting the model to the data; calculation for any given value and; the use of stepwise integration and measurement of likelihoods and trajectories in the simulation process.

Moving on to the climate change simulation, he presented several slides along with commentary, which illustrated how carbon dioxide (CO2) in parts per million (ppm) could be plotted against planetary temperature rise.

One slide was a chart of CO2 against temperature starting with values from the year 1800 when the level was 280 ppm. This clearly shows exponential growth. In the first 100 years, the increase was around 15 ppm, (to 295 ppm) from 1900 to 2000 the increase was an additional 75 (to 370 ppm) and from 2000 to today, it has gone up another 45 ppm (to 415ppm) and is showing no signs of slowing down. At the predicted rate of increase, CO2 levels could reach 700 ppm by 2100 corresponding to a life-threatening 7-degree Celsius rise in planetary temperature over that of 1800.

There are currently almost 3,300 gigatonnes of CO2 in the atmosphere. To return to pre-1800 levels requires the removal of 1,300 GT plus any additional CO2 that is released while this is being extracted. Net zero is not enough!

Russell’s PowerPoint presentation is available at: https://bit.ly/445IQX9