The scientific basis for scepticism about global warming

As a recently retired scientist who has worked in advanced aspects of climatology and mathematical modelling, I am familiar with the scientific details of global warming*. Having been a consultant in this area in both the private and public sectors I also appreciate the dilemmas of decision-makers assigned to deal with potential problems of global warming (see Bell, 1989). Despite acknowledgement of its threats by most governments there is still much scepticism in the scientific and business communities about the significance of global warming and how much human activity has contributed to it. My aim in this paper is to review and assess the main grounds for this scepticism.