Special Reports
Increase in Tropospheric Nitrogen Dioxide over China Observed from Space

September 2005

Emissions from fossil fuel combustion and biomass burning
reduce local air quality and affect global tropospheric chemistry. Nitrogen
oxides are emitted by all combustion processes and play a key part in the
photochemically induced catalytic production of ozone, which results in summer
smog and has increased levels of tropospheric ozone globally. Release of
nitrogen oxide also results in nitric acid deposition, and—at least
locally—increases radiative forcing effects due to the absorption of downward
propagating visible light.

Nitrogen oxide concentrations in many industrialized
countries are expected to decrease3, but rapid economic development has the
potential to increase significantly the emissions of nitrogen oxides
in parts of Asia. Here we present the tropospheric column amounts of nitrogen
dioxide retrieved from two satellite instruments GOME, and SCIAMACHY over
the years 1996–2004.

We find substantial reductions in nitrogen dioxide
concentrations over some areas of Europe and the USA, but a highly significant
increase of about 50 per cent—with an accelerating trend in annual growth
rate—over the industrial areas of China, more than recent bottom-up inventories


Promoting Green Building Design, Construction and Operation, Sustainable Living,
Clean Technology, Renewable Energy Resources and Energy Independence