HyCare ACCENT

Hydrogen (H2) is a key energy carrier for the future. The introduction of a large-scale hydrogen economy might entail changes in the composition of the atmosphere at both regional and global scale. Research on atmospheric H2 assesses these changes and the resulting consequences for the environment. The HyCARE initiative aims at facilitating such research.

Hydrogen in the atmosphere
H2 is one of the most abundant trace gases in the atmosphere. The main sources (fossil fuel combustion, biomass burning, photochemical production, biogenic N2 fixation, oceans) and sinks (uptake by soils, oxidation by OH radicals) are well identified. However, uncertainties of all terms in the H2 budget are very large and published results on H2 trends in the atmosphere are contradictory.

Environmental impacts of a H2 economy
It is generally considered that a H2 economy would have major effects on the composition of the atmosphere. While most of these would be beneficial such as improved regional air quality, the increased usage of H2 also bares potential risks for the environment due to increased H2 emissions from production, storage and distribution of H2. This could lead to e.g.

  • More water vapour in the stratosphere leading to stratospheric cooling, more polar stratospheric clouds and enhanced stratospheric ozone depletion,
  • Increase of the tropospheric lifetime of greenhouse gases such as CH4 and amplification of their radiative effects.
Recent studies disagree about the potential environmental benefits and risks of a H2 economy. Reliable predictions are also impeded because H2 emissions are hard to predict and H2 production pathways and trade-offs are uncertain.

Atmospheric hydrogen research in the EU
Two European FP6 research projects currently aim at a better understanding of atmos­pheric H2. The EUROHYDROS project established a quality-controlled network of continuous H2 measurements and investigates the European H2 sources. Computer models simulate regional emissions, the global atmospheric H2 cycle, and the impact of changing H2 levels on the environment. The HYMN project analyzes trend variability, global budgets and large-scale interactions with the biosphere. However, current studies are still at an exploratory stage and are partly based on simplified assumptions.

Future research needs
Sustained efforts are required to further improve our understanding on atmospheric H2. Appropriate research comprises activities such as:

  • continuing the European H2 related activities (measurement networks, process studies, computer simulations etc.) after the end of the FP6 projects,
  • minimizing uncertainties by profiting from advanced cutting-edge tools,
  • keeping emission scenarios for models up-to-date through the continuous interaction between industry and academia,
  • including more sophisticated air quality and climate issues in experimental and computer scenario H2 studies.
HyCARE seeks to support such future activities and to help arrange financial support.
last change 17.04.2008 | | Print