In the speech “The route to a sustainable future”, the speaker, Alex Steffen, gave his speech focusing on one word－sustainability. He uses the waste created by humanity and unfair usage of natural resources to reach through his point about why we need “world changing”. He gives two solutions that they are still studying for in order to reach this goal. One is building up a bright green city by enhancing the living quality and the population density in a city. Another solution is about implements for collaboration, it is particularly about there will come out distinct solutions once people have their chances to cooperate and innovate. In the end, the author believes that one day the humanity will make the world better.