These emissions contribute to air pollution and are a major ingredient in the creation of smog in some large cities.

By law, new emissions cannot contribute so many pollutants that they push the region back out of compliance.

This makes transport on a hemispherical scale possible and emissions in any continent can thus contribute to the deposition in other continents.

Vehicular and industrial emissions increasingly have contributed to air pollution in urban areas.

With 180 million vehicles on the road, cutting emissions by a third would certainly contribute to cleaner air.

These emissions contribute to ozone formation, which is one of the air pollution problems we have still not solved.

But at the same time, emissions from Spain contribute to the acidification of an area five times the size of its own forest areas.

It is known that these emissions contribute to global warming, but they also create hypoxia within these areas.

As well as the economic cost of lost commodities, fugitive emissions contribute to air pollution and climate change.

Mayor Bloomberg knows these emissions contribute to global warming and has called the problem "one of the most urgent tests of our time."