The second part of the study will be conducted this summer, because emissions levels are highest then.

In 2009 Russia was ready to reduce emissions 20-25% from its 1990 emission levels by the year 2020.

It is not clear whether such low emission levels can be maintained for 100,000 miles, the California requirement.

Reduction goals are based on a percentage of a country's 1990 emission levels, and begin taking effect in 2008.

There is no doubt that trade in emission levels provides such a solution.

The vehicle achieved the emission levels mandated by Congress for 1976.

More stringent monitoring will be carried out of emission levels.

The program's target - a 10 percent reduction in current emissions levels by 2019 - is modest indeed.

Lighter weight means lower fuel consumption and thus also reduced emissions levels.

As a result, emission levels are now less than 10 per cent of those that existed before we introduced these limits.