Prince Abdulaziz bin Majed bin Abdulaziz, Governor of Madinah region opened here today the activities of Enviro Cities 2012 International Conference, under the title "Climate change and the role of cities", organized by the Secretariat of Madinah region in cooperation with the Environmental Center for Arab Towns and Dubai Municipality. Attended by 250 specialists, the 3-day conference is also organized with the support of the Arab Towns Organization and the participation of 19 speakers from eight countries in the field of environment.