
According to the Hedges Company, an automotive marketing company, as of the end of 2020 more than 287.3 million vehicles were on the roads of America. Compare this number with the population of the U.S, whether it is the total number of cars or the number of cars per capita, the United States has a leading position in the world. Greenhouse gas emissions from automobile exhaust account for 30% of total carbon emissions in the U.S; this ratio is the highest in the world. It is undeniable that the increase in the number of motor vehicles has improved our quality of life, but at the same time, the sharp increase in exhaust emissions has caused a serious threat to our environment.

A serious problem with a large number of cars is air pollution. According to Georgia’s Clean Air Force, “Air pollution is not just a threat to our health, it also damages our environment. Toxic air pollutants and the chemicals that form acid rain and ground-level ozone damage trees, crops, wildlife, lakes, and other bodies of water. Those pollutants also harm fish and other aquatic life.” From the above quotations, we can see that the chemical components in exhaust gas are one of the culprits that damage our ecology. It is clear the government’s restrictions and regulations to limit emissions become very important to solve the climate change problem.
To deal with air pollution, most developed countries and even some developing countries require emission tests. Unfortunately, in the United States, only 31 of the 50 states require Emissions Tests. In other words, vehicles registered in 29 states do not need to undergo any emission test to be legally on the road. Additionally, in some states only a small number of counties require emission tests. For example, in Georgia, cars in only 13 counties need to pass the emission test to renew the tag but there are a total of 159 counties in Georgia making the test rate less than 1/10.
An emission test can effectively identify and stop heavy-polluting vehicles from being driven. This test is very helpful in slowing down the speed of Global Temperature Rise. According to Georgia’s Clean Air Force, “Georgia’s I/M Program has prevented tons of ozone-forming pollutants from entering the air we breathe by identifying and repairing more than 3.8 million heavy-polluting vehicles.” Know that this is only happening in 13 counties. If the whole state and even the whole country require emissions tests, this will greatly reduce the air pollution problem.

Map of States Requiring Periodic Vehicle Emissions Testing.
Not only that, we can find the emission tests requirements performed by most states far below EU (European Union) standards, and there are many vulnerabilities. According to Georgia emissions testing requirements for 2021 registration, we can see only 1997-2018 model year gasoline-powered cars and light-duty trucks require emission tests, and the diesel vehicle is not within the scope of the test. But the fact is that the exhaust gas of diesel vehicles pollutes are more serious, because diesel engines emit a lot of nitrogen oxides and PM2.5 which cause smog in the city, and the smog will eventually build up in the atmosphere, causing the greenhouse effect. Also, the investigation in EU countries which require the emissions tests for diesel vehicles found that excessive emissions of diesel vehicles cause air pollution which kills 5000 people in EU countries every year. If diesel exhaust emissions such as nitrogen oxides are reduced, 8,000 people will be saved from death. It is hard for us to believe how much impact on our environment and health will be cost by excessive emissions of diesel vehicles in the United States due to government negligence.

Whether it is the penetration rate of emission testing or the requirements of emission testing it is clear that the United States is far below testing rates of most developed countries and even some developing countries. Although most vehicles meet the requirements of the Environmental Protection Agency when they are produced or imported, but as car ages increase many vehicles are in disrepair and cause serious pollution. Obviously, our current Clean Air Act is outdated for the increasingly serious Climate Change and air pollution. As a member of the Paris Agreement, we need to do a better and there is a lot of room for the U.S. government to make improvements.