Impact of a future H2-based road transportation sector on the composition and chemistry of the atmosphere – Part 1: Tropospheric composition and air quality D. Wang1, W. Jia1, S. C. Olsen1, D. J. Wuebbles1, M. K. Dubey2, and A. A. Rockett3 1Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA 2Earth Systems Observations, Los Alamos National Lab, Los Alamos, NM, USA 3Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
Abstract. Vehicles burning fossil fuel emit a number of substances that change the
composition and chemistry of the atmosphere, and contribute to global air
and water pollution and climate change. For example, nitrogen oxides and
volatile organic compounds (VOCs) emitted as byproducts of fossil fuel
combustion are key precursors to ground-level ozone and aerosol formation.
In addition, on-road vehicles are major CO2 emitters. In order to
tackle these problems, molecular hydrogen (H2) has been proposed as an
energy carrier to substitute for fossil fuels in the future. However, before
implementing any such strategy it is crucial to evaluate its potential
impacts on air quality and climate. Here, we evaluate the impact of a future
(2050) H2-based road transportation sector on tropospheric chemistry
and air quality for several possible growth and technology adoption
scenarios. The growth scenarios are based on the high and low emissions
Intergovernmental Panel on Climate Change Special Report on Emissions
Scenarios, A1FI and B1, respectively. The technological adoption scenarios
include H2 fuel cell and H2 internal combustion engine options.
The impacts are evaluated with the Community Atmospheric Model Chemistry
global chemistry transport model (CAM-Chem). Higher resolution simulations
focusing on the contiguous United States are also carried out with the
Community Multiscale Air Quality Modeling System (CMAQ) regional chemistry
transport model. For all scenarios future air quality improves with the
adoption of a H2-based road transportation sector; however, the
magnitude and type of improvement depend on the scenario. Model results show
that the adoption of H2 fuel cells would decrease tropospheric burdens
of ozone (7%), CO (14%), NOx (16%), soot (17%), sulfate
aerosol (4%), and ammonium nitrate aerosol (12%) in the A1FI scenario,
and would decrease those of ozone (5%), CO (4%), NOx (11%), soot
(7%), sulfate aerosol (4%), and ammonium nitrate aerosol (9%) in
the B1 scenario. The adoption of H2 internal combustion engines
would decrease tropospheric burdens of ozone (1%), CO (18%), soot (17%),
and sulfate aerosol (3%) in the A1FI scenario, and would decrease those of
ozone (1%), CO (7%), soot (7%), and sulfate aerosol (3%) in the
B1 scenario. In the future, people residing in the contiguous United States
could expect to experience significantly fewer days of elevated levels of
pollution if a H2 fuel cell road transportation sector were to be adopted.
Health benefits of transitioning to a H2 economy for citizens in
developing nations, like China and India, will be much more dramatic,
particularly in megacities with severe, intensifying air-quality problems.
Citation: Wang, D., Jia, W., Olsen, S. C., Wuebbles, D. J., Dubey, M. K., and Rockett, A. A.: Impact of a future H2-based road transportation sector on the composition and chemistry of the atmosphere – Part 1: Tropospheric composition and air quality, Atmos. Chem. Phys., 13, 6117-6137, doi:10.5194/acp-13-6117-2013, 2013.