Tune in to CBC Radio’s Ideas program to hear the final episode of the ideacity series. ideacity is a three day festival of talk, produced and hosted by Moses Znaimer. The focus this year was optimism and pessimism. In this episode, Andrew Sharpless, head of Oceana, speaks about caring for the world’s oceans; Edith Widder, oceanographer and deep sea explorer talks about reversing marine ecosystem degradation; and Preston Manning, envisions building knowledge and ethics for future political leaders. For more information about ideacity and future conferences, sign up for the ideacity newsletter.