As a consequence, we can expect more days of extreme heat and fewer of extreme cold globally. We can also expect more heavy precipitation resulting from a moister atmosphere. These are examples of simple extreme events. Importantly, these are the kinds of extremes that matter most to human wellbeing. As a result, the IPCC has introduced an assumption of harm into its policy recommendations.
Human societies have the potential to develop and manage environmental change.
As regards human wellbeing, the level of development is by far the most important causal factor in determining the impact of environmental change. One consequence of the assumption of harm is that the public discussion often ignores this. This is reinforced by the cultural framework in which climate change is discussed, which tends to see economic and technological development as part of the problem, rather than the solution. Take, for example, CNN's warning of 'enormous loss of both human and animal life due to greater risk from diseases like malaria'. Most importantly, aspects of the human environment, such as the level of sanitation and other basic factors affecting health and parasite spread, are the key determinants.