|
|
 |
 |
 |
In recent years, the issue of climate change has become a frequently discussed policy topic because of its potential consequences and its inherent complexity. Over the last 10,000 years, the Earth's climate has remained relatively stable. However, technological advances have led to anthropogenic modifications of the atmosphere's composition, and thus could have significant impacts on the global climate. Now policy makers are faced with daunting task of adopting appropriate strategy to deal with this issue.
Since the advent of the industrial age, atmospheric concentrations of greenhouse gases have gradually increased. Atmospheric concentrations of carbon dioxide have risen by approximately 30% since that time; methane, by greater than 100%; and nitrous oxide, by 15%. These increases in atmospheric concentrations of greenhouse gases (which tend to warm the earth's surface) have accelerated the natural warming of the earth's surface (the greenhouse effect) to abnormal levels {1}.
This anthropogenic contribution to greenhouse gases is expected to have significant effects on the global climate. Scientific models have predicted that the phenomenon of global climate change may result in a 1 to 3.5oC warming of average global temperatures by 2100. Although individual modelers disagree about the potential impacts of climate change, models also suggest numerous other climate change predictions: a 7% increase in precipitation and subsequent 15-95 cm rise in sea levels; increased occurrences of extreme weather conditions such as hurricanes, droughts, hot and cold spells, and river floods; a dieback of forests in the low latitudes; increased mortality rates due to heat waves and increased habitable ranges for insects carrying vector-borne diseases; increased stress on water supplies; and decreased quality of water and air {1}. Thus, climate change could have numerous social and economic consequences.
Because of the potential impacts of climate change, decision makers must employ an analytical framework by which to determine the most appropriate strategy to address this issue. Because of our society's limited resources, decision makers normally compare the benefits and costs of an action through a cost-benefit analysis. Using this analytical framework, government actions taken to mitigate climate change are only justified when their benefits exceed its costs. According to economic theory, only measures whose marginal costs (the cost of reducing an additional until of emissions) are greater than marginal benefits (benefit or avoided damages of decreasing emissions by one unit) should be implemented {5,3}. The optimal level of abatement occurs when the marginal benefits of abatement and the marginal costs of abatement are equal (Figure 1).
This research represents an effort to move our society ever closer to determining this optimal level of abatement. To this end, this website considers the usefulness of the cost-benefit analysis in the evaluation of climate change policy. It considers the estimated net benefits of climate change mitigation. It also examines the estimated costs of mitigation, through emissions reduction and carbon sequestration. It concludes with policy recommendations, which bear in mind the difficulties of evaluation climate change policy within the cost-benefit framework and the uncertainties inherent in cost and benefit estimates.
One caveat must be made before moving forth through the web site. The information presented represents a collection of and discussion regarding benefit estimates, and a collection of and discussion regarding cost estimates. The estimates presented are generally based on models focusing on a given sector and including a limited amount of feedback effects with the rest of the economy. A more complete approach to exploring the welfare economics implications of climate change would also include a the results from Integrated Assessment Models.
Integrated assessment models attempt to synthesize the current scientific, technical, economic and sociopolitical knowledge. This synthesis will help identify and assess the risks associated with climate change, ecosystem responses, and human adaptation, as well as the feasibility effectiveness, cost, and side-effects of potential mitigation measures [1]. The successful completion of a model that full integrates all these aspects of climate change is not yet a reality, however, attempts have been made to incorporate as much of the effects as possible.
There are several useful purposes or goals of integrated assessment models (IAMS) that help illustrate their importance in the climate change debate. First, IAMS can help assess potential responses to climate change by making projections of the likely costs and effects of specific responses [1]. Second, IAMS can be used to promote a broad view of the climate change issue and can help in assessing uncertainties. Finally, IAMS can help in the comparison of climate change with other social problems and help determine the aggregate social effect of climate change and potential responses [1].