I doubt it.

Consider a simple plastic toy: the little thing with a pole in the middle, it rocks back and forth, and you stack graduated sizes of plastic rings on it? I used to make those in a factory.

That plastic starts out as a cold pellet, about the size of a BB. It is melted, using electicity, at a temp of hundreds of degrees. Part of the object that actually does the melting is a huge cone of solid metal (The extruder 'nozzle'.) It is so thick and solid that it has to heat up for about a day before it can be used. During this time it is simply consuming electrical energy -- buttloads of it -- with no output of melted plastic.

When this part is ready, more electrically-powered machines convey the plastic BB's through a series of pneumatic pipes (and energy was also required to compress that air) to the individual presses, where they are heated, mixed with color in another machine, then added to the press itself. A tube of hollow plastic (think of it as a sock) drops from the extruder and then the press closes around it. Air is injected so the 'sock' expands to the shape of the mold. Cold water (read: cooled using electric power) is cycled through the mold to cool down the portion of the plastic that will become your part; the rest is usually left hot so that it is easier to separate.

These presses are hydraulic. The fluid gets hot and sometimes it too needs to be cooled. It takes anywhere from about thirty seconds to several minutes to form a part in the mold, depending on what exactly it is, its particular type of plastic (HDPE, HPE, etc), and on and on. . . .

The net result is that there is no way we locked up more carbon in that little toy than we consumed (in energy) during its production. Plus, that plastic pellet we melted used to be crude oil. How much energy went onto creating the pellets? Another one to consider -- the amount of energy used by an automobile factory: very little carbon is being locked up in metal parts, yet vast amounts of energy are used to form and assemble them.