Query: CO2 is not powerful in that sense, the only thing it does in the system is make the planet greener.

Relevant passages:
City <=SEP=> A city is a large and permanent human settlement . Although there is no agreement on how a city is distinguished from a town in general English language meanings , many cities have special administrative , legal , or historical status based on local law .   Cities generally have complex systems for sanitation , utilities , land usage , housing , and transportation . The concentration of development greatly facilitates interaction between people and businesses , sometimes benefiting both parties in the process , but it also presents challenges to managing urban growth .   A big city or metropolis usually has associated suburbs and exurbs . Such cities are usually associated with metropolitan areas and urban areas , creating numerous business commuters traveling to urban centers for employment . Once a city expands far enough to reach another city , this region can be deemed a conurbation or megalopolis . Damascus is arguably the oldest city in the world . In terms of population , the largest city proper is Shanghai , while the fastest-growing is Dubai .

Orbital ring <=SEP=> An orbital ring is a concept for a space elevator that consists of an artificial ring placed around the Earth that rotates at an angular rate that is faster than the rotation of the Earth . It is a giant formation of astroengineering proportions .   The structure is intended to be used as a space station or as a planetary vehicle for very high speed transportation or space launch .   The original orbital ring concept is related to the space fountain and launch loop .

Captain Planet and the Planeteers <=SEP=> Captain Planet and the Planeteers is an American animated environmentalist television program created by Ted Turner and Barbara Pyle . The series was produced by Turner Program Services and DIC Entertainment and it was broadcast on TBS from September 15 , 1990 , to December 5 , 1992 . A sequel series , The New Adventures of Captain Planet , was produced by Hanna-Barbera and Turner Program Services and was broadcast from September 11 , 1993 , to May 11 , 1996 . Both series continue today in syndication . The program is a form of edutainment and advocates environmentalism and is famous for having a number of famous actors providing voices for the villains .   In February 2009 , Mother Nature Network began airing episodes and unreleased footage of Captain Planet and the Planeteers on its website .

Marvel Universe <=SEP=> The Marvel Universe is the shared universe where the stories in most American comic book titles and other media published by Marvel Entertainment take place . Marvel superheroes such as the Avengers , the Fantastic Four and the X-Men are from this universe .   The Marvel Universe is further depicted as existing within a `` multiverse '' consisting of thousands of separate universes , all of which are the creations of Marvel Comics and all of which are , in a sense , `` Marvel universes '' . In this context , `` Marvel Universe '' is taken to refer to the mainstream Marvel continuity , which is known as Earth-616 or currently as Earth Prime .