Emissions describe gases and particles put into the air. These are often waste products from cars, factories, or other sources.
What are greenhouse gas emissions?
Greenhouse gas emissions are gases vented into the Earth’s atmosphere, the result of human activity. (We’re the worst.) These gases absorb infrared radiation emitted from the Earth’s surface and reradiate it back, leading to global warming—which, yes, does exist, despite your cousin’s Facebook posts.
Greenhouse gases also cause air pollution, aka smog, impacting air quality.
Here’s a rogue’s gallery of the top greenhouse gases and where they come from.
- Carbon Dioxide (Co2): primarily from burning oil, coal, and gas
- Methane (CH4): from oil and gas, livestock digestion and poop, and landfills
- Nitrous Oxide (N20): a byproduct of fuel combustion, mainly from coal-fired power plants
- Fluorinated gases (F-gases): from gas leakages during the manufacture of air conditioners, foams, aerosols, and refrigerators
What causes greenhouse gas emissions?
According to the EPA, the American obsession with motor vehicles has been a direct cause of increased greenhouse gas emissions over the last 150 years. But the industrial revolution wasn’t so great for Mother Earth, either.
The top sources of greenhouse gas emissions in 2019 were:
- Transportation: Planes, trains, and automobiles that run on fossil fuels led to 29% of emissions.
- Electricity production: Burning fossil fuels like coal and natural gas to produce electricity caused 25% of emissions.
- Industry: Converting raw materials to finished goods, and electricity used for industry, was a contributor of 23% of emissions.
- Agriculture, land use, and forestry: Combined, these industries caused 22% of emissions. Think cow manure and land areas that absorb more carbon dioxide than they emit.
- Commercial and residential: Spoiler alert—individual households don’t cause as much damage as you’d think. Commercial and residential use for heat and waste handling only caused 13% of emissions.
What is emissions testing?
States regulate motor vehicles’ emissions to reduce global greenhouse gas emissions and improve air quality.
So what happens during emissions testing at your local garage or inspection station? At the vehicle emissions testing station, a computer measures the amount of pollutants your car emits. They hook your car’s tailpipe up to a computer for an On Board Diagnostics test. This methodology compares your motor vehicle’s emissions to state-specified limits.
If your vehicle’s carbon dioxide emissions pass, you get a sticker that goes on your windshield—exciting! It’s good for a year. If you fail, you have to obtain a waiver, or get your vehicle repaired.
Is emissions testing required?
Every state has different rules about emissions testing, and not all states care so strongly about emissions reductions. Vehicle emissions testing isn’t required in Alaska, Arkansas, Iowa, Minnesota, Montana, South Carolina, and South Dakota; Michigan and Mississippi only require it in certain scenarios. America, we’ve got to step things up.
Keep the receipts for those repairs, though, because if your test results fail again, you might have to apply for another waiver or economic hardship exemption.
What about electric cars?
There’s plenty of benefits to having an electric car. For instance, you get to feel morally superior to everyone burning coal around you in their old-fashioned, gas-guzzling vehicles! You also get to do your small part to avoid a total meltdown of the planet by the year 2050.
But there are other benefits! For one, you won’t have to sit in line at an inspection station to get your Tesla or Prius tested for emissions. And many states have started offering tax credits for EV drivers.