President Barack Obama on Tuesday unveiled an aggressive policy initiative to increase U.S. auto fuel efficiency and regulate auto emissions.
In a bid to reduce climate-warming greenhouse gasses, countries around the world have adopted a patchwork of ways to regulate emissions from vehicles. These varied approaches carry with them different standards for curbing emissions -- from measuring efficiency in miles per gallon to determining grams per kilometer of pollution in a car's exhaust.
Here are highlights of the emission-cutting plans of some of the world's biggest emitters.
* Requires yearly 5 percent increases in fuel efficiency from 2012 through 2016, resulting in an average fuel economy standard of 35.5 miles per gallon in 2016.
* Cuts oil consumption by an estimated 1.8 billion barrels over the life of the program.
* Cuts greenhouse gas emissions by a projected 900 million metric tons.
* The EU came to a provisional deal in December to cut car emissions. The plan awaits approval by the parliament and member countries but it is not expected to change much.
* Average carbon emissions from new cars would be cut by 18 percent to 130 grams per km in a phased approach.
* Car manufacturers would need to bring 65 percent of their fleet into compliance by 2012, 75 percent by 2013, 80 percent by 2014 and 100 percent by 2015.
* Manufacturers would incur fines of 5 euros, or $6.80, per car for overshooting the target by a gram; 15 euros, or $20.41, per car for the second gram; and 25 euros, or $34.02, for the third. Carmakers that overshoot by more than three grams would be fined 95 euros, or $129.29, for each gram in excess. After 2018, any excess in emissions would incur a fine of 95 euros per car.
* The plans calls for emissions to be cut to an average of 95 grams per kilometer by 2020.
* China enacted its first emissions standards on cars in 2000, which mirrored standards the EU put in place in 1992.
* Beijing has adopted tougher standards identical to the EU policies enacted in 2006, known as Euro 4. China will enact these standards nationwide in 2010.
* Under the standards currently followed in most of China, cars that run on gasoline can emit 2.3 grams per km of carbon monoxide, 0.2 gram per km of hydrocarbons and 0.15 gram per km of nitrogen oxides.
* The tougher standards that will be enacted allow cars that run on gasoline to emit 1 gram per km of carbon monoxide, 0.1 gram per km of hydrocarbons and 0.08 gram per km of nitrogen oxides.
* The 2005 heavy duty emission standards were the most stringent diesel emission regulations in the world when they were enacted.
* The 2009 standards limit emissions even further to 0.7 g/kWh for nitrogen oxides and 0.01 g/kWh for particulate matter.
* Diesel passenger cars, not gasoline cars, are subject to 1997/98 vehicle standards which are retroactively applied to older vehicles.
* Car owners must either replace their older cars with newer, cleaner models or they must retrofit old cars with approved nitrogen oxide and particulate matter control devices.
* Diesel passenger cars have nine years from their initial registration to comply.
(Compiled by Jasmin Melvin; Editing by Cynthia Osterman)