.... hurts air quality,
Tailpipe fumes contain the six criteria pollutants that ...
... that add to urban smog and contribute to global warming. This smog kills plants and trees, corrodes our roads, bridges and buildings and consumes our city on hot days.
Idling contributes to global climate change. Greenhouse gas emissions from vehicles, including carbon dioxide (CO2), cause climate change. A serious threat to the planet, overwhelming scientific evidence links climate change to the earth's highest ever average annual temperatures, melting polar ice caps, rising sea levels, increasingly severe weather events, and to the threat of many plant and animal species.
The Greenhouse Effect relates to global warming in that it's the reason why excess heat from the surface of the Earth is not dispersed into space. The glass on a greenhouse allows one type of radiation in, but reduces the amount of another type that can escape--causing the interior of the greenhouse to remain warm. This is what we are experiencing on our planet - gases such as carbon dioxide and methane act as the glass; allowing solar radiation in, but preventing heat from escaping.
Carbon Dioxide Emissions Calculator