He said this while addressing the world's mayor conference held by C-40 in Copenhagen Denmark, said a statement issued here on Friday.
Waseem Akhter said that these problems would further become complex with the passage of time and therefore we must take this as a collective issue.
The Mayor of Karachi said that he as Mayor despite limited resources, has taken various measures to ensure healthy environment in Karachi.
He also invited all Mayors to visit Karachi and said Karachi is business and trade hub of Pakistan and said, "I as Mayor of the city would welcome investment in our city".