Impacts of aviation fuel sulfur content on climate and human health

Abstract

Abstract. Aviation emissions impact both air quality and climate. Using a coupled tropospheric chemistry-aerosol microphysics model we investigate the effects of varying aviation fuel sulfur content (FSC) on premature mortality from long-term exposure to aviation-sourced PM2.5 (particulate matter with a dry diameter of < 2.5 µm) and on the global radiation budget due to changes in aerosol and tropospheric ozone. We estimate that present-day non-CO2 aviation emissions with a typical FSC of 600 ppm result in ∼ 3600 [95 % CI: 1310–5890] annual premature mortalities globally due to increases in cases of cardiopulmonary disease and lung cancer, resulting from increased surface PM2.5 concentrations. We quantify the global annual mean combined radiative effect (REcomb) of non-CO2 aviation emissions as −13.3 mW m−2; from increases in aerosols (direct radiative effect and cloud albedo effect) and tropospheric ozone. Ultra-low sulfur jet fuel (ULSJ; FSC = 15 ppm) has been proposed as an option to reduce the adverse health impacts of aviation-induced PM2.5. We calculate that swapping the global aviation fleet to ULSJ fuel would reduce the global aviation-induced mortality rate by ∼ 620 [95 % CI: 230–1020] mortalities a−1 and increase REcomb by +7.0 mW m−2. We explore the impact of varying aviation FSC between 0 and 6000 ppm. Increasing FSC increases aviation-induced mortality, while enhancing climate cooling through increasing the aerosol cloud albedo effect (CAE). We explore the relationship between the injection altitude of aviation emissions and the resulting climate and air quality impacts. Compared to the standard aviation emissions distribution, releasing aviation emissions at the ground increases global aviation-induced mortality and produces a net warming effect, primarily through a reduced CAE. Aviation emissions injected at the surface are 5 times less effective at forming cloud condensation nuclei, reducing the aviation-induced CAE by a factor of 10. Applying high FSCs at aviation cruise altitudes combined with ULSJ fuel at lower altitudes results in reduced aviation-induced mortality and increased negative RE compared to the baseline aviation scenario.

Mitigating the Climate Impact from Aviation: Achievements and Results of the DLR WeCare Project

“…Further analyses, including also a sensitivity experiment with low-sulfur aviation emissions, also suggest that aviation-induced aerosol sulfate is the key component in this context, being transported downward from the flight levels to relatively low altitudes where it affects cloud droplet number concentration and radius. Hence perturbations to low-clouds are driving the large RF simulated here, as also reported in similar studies [21,127]. In agreement with these investigations, our analyses also reveal that the assumptions on the size distribution of emitted sulfur particles are essential.…”

“…Recent studies suggest that aerosols have a considerable climate effect via formation and modification of the characteristics of low level clouds ( [21,125,127], see also Section 3.3) and ice clouds (cirrus, [165], see also Section 2.2.2). One of the major future activities should therefore be to better characterize these aerosol-cloud interactions, quantify the impact of aviation's aerosol emissions on all clouds and to make these effects available for climate impact assessments, e.g., via the calculation of CCFs (Section 2.2.3).…”

Is cancer prevention influenced by the built environment? A multidisciplinary scoping review

“…[90][91][92] There is a need for new cross-disciplinary fields of research and praxis in cancer-environment studies to leverage the capabilities and techniques of the medical, natural, and social sciences. Of the research captured, more than 20% was found in databases, and written by authors, outside the medical sciences.…”

“…Valuable contributions to understanding screening behaviors, lifestyles, and the production of harmful pollutants can be sourced from fields outside the medical sciences. [90][91][92] There is a need for new cross-disciplinary fields of research and praxis in cancer-environment studies to leverage the capabilities and techniques of the medical, natural, and social sciences. Studies of the impacts of food landscapes, active mobility, and non-residential-based environments on cancer etiology could be novel areas of future collaborative research.…”

Feasibility of climate-optimized air traffic routing for trans-Atlantic flights

“…Recent studies (e.g. Gettleman and Chen 2013, Righi et al 2016, Kapadia et al 2016 indicate that these effects may be substantial, but also that there are large uncertainties in their quantification. We have enough information and knowledge about major atmospheric processes to start the implementation and demonstration in an operational environment.…”