What is the solution of concrete jungle?

Answer 1

If you mean the pollution and running out of coal and oil energy, I'd say the world [mostly the U.S.] needs to start converting to solar and wind energy, fossil fuels will fade, but nature energy will last as long as the sun does. Or if a natural disasture kills most of the overweight, uneducated, greedy people of this world the earth would fix itself.... I personally like plan A.