Is ethylene gas a contributor to global warming?

Question

It is an industrial product used to manufacture other chemical products and plastics. It's also used as a welding gas. In modern medicine it's used as an anesthesia and for sterilization of surgical components and equipment. And it's also a naturally occurring plant hormone that accelerates flowering and ripening. Banana, peach, apple, onion, and tomato fruits both use it and produce it.

Answer 1

Not much, it reacts with other chemicals at relatively low temeratures so it doesn't last long enough to directly cause any problems.

Answer 2

The background atmospheric concentration of ethylene is on order of 1 ppbv.  That's a factor of 300,000 less than CO2 in terms of concentration.  For ethylene to be important in global warming, its greenhouse warming potential (GWP) would therefore have to be around 300,000.  That is a huge number for a GWP, a factor of 10 higher than sulfur hexafluoride.  Methane, in contrast, has a GWP of around 72 for a 20 year timescale, and ethylene is more reactive than methane, so based on reactivity alone its GWP will be lower than methane at 20 year timescales.  

In short, no, ethylene is too reactive and there isn't enough of it for it to be important in global warming.