NOx emissions, or Oxides of Nitrogen, is a byproduct of combusted fuel and is a contributor to smog.
Particulate matter contains microscopic solids and liquid droplets that can be inhaled. Fine particles, smaller than 2.5 micrometers, pose the greatest risk to our health and cause hazy skies.
Carbon dioxide is a heat-trapping gas that comes from burning fossil fuels and wildfires. Atmospheric CO2 increased 50% since the industrial revolution in the 18th century.
Volatile organic compounds are emitted as gasses from manmade chemicals and petroleum fuels. VOCs can react with nitrogen oxides to pollute the ozone.