The 40th IIASA International Conference "Worlds within Reach - From Science to Policy" will be about the impacts of major transformation of modern world, such as globalization, fundamental shifts in economic and political power, escalating environmental challenges, and deep social conflicts, on current sustainability and development challenges. In order to impose and examine options for resolving those challenges the conference aims to explore new future worlds, which are able to accommodate our collective needs and aspirations, while living within, and respecting, planetary boundaries.