As is widely known, global warming has been occurring since the industrialization of the world's economy. It has now reached a level where serious, difficult-to-reverse changes are occurring in our environment. Yet, while governments talk about the need to reduce carbon dioxide emissions - the principal cause of the rise in temperature - the level of CO2 present in our atmosphere goes on increasing steadily with no sign of levelling out, still less of falling.
Thus, unless this pattern changes rapidly, emergency measures will be needed, at least for a few decades, until the world does figure out how to sustain a style of living without substantial CO2 release. The lecture will focus mainly on a strategy known as Solar Radiation Management (i.e. reducing the amount of sunlight reaching the earth) and, within that group of approaches, on Marine Cloud Brightening. This entails the brightening of low-level marine stratus clouds by adding many additional cloud-condensation nuclei (CCN) to make the clouds more reflective. The proposed route for doing this is by way of a fleet of unmanned ships powered by Flettner rotors with added performance achieved by adding discs to the rotors. Some of the details of these craft including the aerodynamic design of the thrust-producing Flettner rotors are examined. The author's team's computations, using Computational Fluid Dynamics (CFD) has shown that the proposed addition of discs to the rotors has a damaging effect on the ship's performance.

Professor Launder was appointed Professor of Mechanical Engineering at the University of California, Davis, in 1976, and stayed there four years until he accepted the Headship of the Thermo-Fluids Division at the University of Manchester Institute of Science and Technology, in 1980. His research group, focusing on the mechanics and mathematical modelling of turbulent flows, particularly in the presence of strong buoyant or rotational forces, became internationally recognized. In particular, his group developed the commonly applied standard k-epsilon turbulence and Reynolds stress transport models. In recognition of his many achievements, Professor Launder was admitted as a Fellow of the Royal Society and the Royal Academy of Engineering, and he has received many international honors, including honorary degrees from two European universities. He also served as the Regional Director of the Tyndall Centre for Climate Change Research, from its creation in 2000 until 2006. While retaining his interests in fundamental turbulence modelling, much of his time nowadays is spent preparing biographical matter and in editorial work.