One of the major concerns today is the rise in global temperatures, which are generally thought to be caused by the release of anthropogenic greenhouse gases. As a result, a growing proportion of the political agenda is occupied by the challenge of implementing policies and strategies in time to mitigate the possible consequences of global warming.

A key element in assessing climate change is the powerful computer simulations used to demonstrate how complex, interacting forcing agents influence the evolution of the climate system. Although the models are built around a long-accumulated understanding of the underlying physical processes and dynamics – and are compared with historical and contemporary observations – there are still many aspects that are less well understood. There is, therefore, a range of views about the reliability of using these models to make credible projections of our future climate.

At the [Institute of Physics] seminar, two leading climate physicists, Prof. Richard S Lindzen, Alfred P Sloan Professor of Meteorology at the Massachusetts Institute of Technology (MIT), and Prof. Alan J Thorpe, chief executive of the Natural Environment Research Council (NERC), described the current status of climate-model prediction from rather different viewpoints. Prof. Lindzen explained the limitations of climate models and outlined why attempts to attribute global temperature rise to an increase in carbon dioxide (CO2) emissions were flawed. He maintained that there was no sound evidence that temperatures would rise substantially in the future. Prof. Thorpe based his presentation on the huge weight of evidence in the scientific literature, showing that current and future warming of the climate is caused by the human input of greenhouse gases. He presented a variety of evidence supporting the validity of current global models on which current concerns about global warming are based. He also stressed that more research was being done and needed to refine the details further.
http://www.iop.org/activity/policy/Events/Seminars/file_25825.pdf