• Costs of research and development borne by governments • Costs of security, such as the Gulf War • Fiscal impacts of balance of payment problems. • Transportation infrastructure costs There are also environmental impacts that have adverse effects on our health, our agriculture, our artifacts, and on the aesthetic attractiveness of our surroundings. These include: • Air and water pollution including acid rain • Toxic and radioactive wastes • Greenhouse gases. Perhaps even more important is the contribution that fossil fuel use makes to a build up of CO2, a key factor in potential climate change. The effects of climate change may be devastating in the long run. The nature and economic impact of this particular effect will be described briefly in the following section. Climate Change The activity of humans has already caused a very substantial increase in atmospheric CO2 over the last 100 years or so. The combustion of fossil fuels accounts for about half of this increase. The other major contributors to greenhouse gasses are the chlorinated fluorocarbons (CFCs) and CO2 from vegetative decay arising from deforestation. Progress is being made on the CFCs and major efforts are going into decreasing the impact of deforestation. Hence the energy sector remains the major arena for action in terms of limiting CO2 production. Most discussions on global warming deal with the temperature rise that will be experienced when the atmospheric CO2 level reaches double the level that prevailed before the industrial revolution. Reaching this level is projected to occur around 2025 if there are no changes to current energy practices. The consensus supported by the Intergovernmental Panel on Climate Change (IPCC) [11] is that average global temperatures will, by 2025, increase between 1.5° and 4.5° C, with a "best guess" central value of 2.5° C. There is considerable uncertainty about the predictions of the global circulation models on which these estimates are based and particularly on the thermal lag brought about as the oceans warm. The uncertainties and modest temperature rises have caused some to ignore the problem [22] and it is clear that world policy makers have yet to react as vigorously to CO2 increases as they did for CFCs in the light of concerns over ozone depiction. There is good evidence that much more modest changes in average temperature than 2.5° C have, in relatively recent historic times, had important effects on human activity and well being. As shown in figure 10, one study of this [12] indicates what has happened with changes on the order of a degree or less.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==