Tradeoffs in human health & mortality associated with aircraft safety measures and fuel use

Airline safety regulations in the United States are often subject to benefit-cost analyses to ensure the benefit to public health and safety from new rulemaking outweighs the economic costs to aircraft manufacturers and... [ view full abstract ]

Airline safety regulations in the United States are often subject to benefit-cost analyses to ensure the benefit to public health and safety from new rulemaking outweighs the economic costs to aircraft manufacturers and operators. As the frequency and severity of commercial airline accidents in the US has decreased dramatically in recent decades, the marginal benefit of new safety measures has decreased as well. Meanwhile, the inclusion of additional safety measures frequently increases aircraft weight.  The corresponding additional fuel consumption impacts not only airline operating costs, as accounted for in current benefit-cost analysis methods, but also represents a marginal increase in global climate change emissions. In this study, we examine the potential marginal human health costs of increased airline fuel use due to climate change. Using case studies of recent commercial airline regulations, we compare the potential impact of including climate-related health costs on the net benefit of these regulations.

Regulatory cost-benefit analyses use the value of a statistical life and disability-adjusted life years to convert health, injury, and fatality to economic parameters. Using global forecast data based on the IPCC SRES A1 scenario, we calculate the weighted global value of a statistical life from 2015 to 2100. Combining this with estimates of the marginal effect of greenhouse gas emissions on global warming and the global health impacts of climate change, we estimate an economic burden of health costs from greenhouse gas emissions due to airline fuel use suitable for use in regulatory benefit-cost analysis.

Results vary widely depending on assumptions regarding the value of a statistical life, sensitivity of climate to greenhouse gas emissions, choice of discount rate, duration of the regulatory change, and the fuel use associated with each regulation. Climate-related social costs of increased fuel use range from $0.05/L (for climate change impacts in the United States over a 20-year fuel use and impact assessment period) to $0.58/L (for global climate change health costs over a 20-year fuel use and 100-year impact assessment period) to $3.10/L (for global climate change health costs using the value of a statistical life chosen by the US Department of Transportation).

While low end cost estimates have minimal impact on analyses results, high end estimates can be a significant factor, nearly doubling the calculated cost of increased fuel burn.  This can result in a cost equivalent to the statistical value of a life for changes that add only a few kilograms per airplane into the global fleet.  Benefit-cost analyses methods that include this cost provide a more accurate way to account for the implicit tradeoff between proximate and global health and safety impacts.