I'm not a big fan of that site, but the answer was

I'm not a big fan of that site, but the answer was ok. And it is also why I posted thi link:

http://environment.nationalgeographic.com/env...-overview/

SO2 has the opposite effect o greenhouse gases. Rather than trapping heat like GHG's, SO2 reflects heat. SO2 contributes to global warming when it is removed from the atmosphere. It's a pollutant that we don't want in the atmosphere so it is good when P2O fuel doesn't add to the pollution. It is not a GHG. Just the opposite.

From the article:

"Another pollutant associated with climate change is sulfur dioxide, a component of smog. Sulfur dioxide and closely related chemicals are known primarily as a cause of acid rain. But they also reflect light when released in the atmosphere, which keeps sunlight out and causes Earth to cool. Volcanic eruptions can spew massive amounts of sulfur dioxide into the atmosphere, sometimes causing cooling that lasts for years. In fact, volcanoes used to be the main source of atmospheric sulfur dioxide; today people are.

Industrialized countries have worked to reduce levels of sulfur dioxide, smog, and smoke in order to improve people's health. But a result, not predicted until recently, is that the lower sulfur dioxide levels may actually make global warming worse. Just as sulfur dioxide from volcanoes can cool the planet by blocking sunlight, cutting the amount of the compound in the atmosphere lets more sunlight through, warming the Earth. This effect is exaggerated when elevated levels of other greenhouse gases in the atmosphere trap the additional heat."

techisbest