Foresight Workshop addressed science needs in implementing Sustainable Development Goals International researchers from the natural, social and engineering sciences and key practitioners and stakeholders came together to anticipate potential challenges for the implementation of the Sustainable Development Goals (SDGs) during a foresight workshop called “Science needs in the context of tough choices in implementing the new SDG framework.” The workshop took place from 18 to 21 April in Italy. It was organized by the German Committee Future Earth (Deutsches Komitee für Nachhaltigkeitsforschung in Future Earth) in cooperation with Future Earth and the Sustainable Development Solutions Network . The event was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation). The aim of this first foresight workshop was to develop a scientific framework that will allow researchers to quantify potential comprehensive solutions for sustainability in the coming years. Such a framework could help decisionmakers develop societally, economically and environmentally efficient instruments and achieve more policy coherence in the realm of sustainability. Because the SDGs have such a broad scope, they open up many possibilities for incoherent policy due to complex dependencies between the goals and targets. In many cases, it may be necessary to prioritize one goal over another, and conflicting issues may lead to tough choices. The foresight workshop addressed the need for a better understanding of the key interlinkages, synergies and tradeoffs embedded in the SDGs to contribute scientific knowledge for policy decisionmaking during the implementation of these goals on a national, regional and global level. More specifically, it focused on the central question: Can we establish a foresight process that enables such issues to be identified more quickly as they emerge, so that solutions requiring new and more indepth upstream fundamental research can be explored in a more timely manner? About 40 leading researchers from around the globe and stakeholders, including decisionmakers and practitioners from the United Nations, participated in the fourday foresight workshop (see list of contributors ). The interdisciplinary team brought together different views on identifying potential technical and political challenges to the implementation of the SDGs. Through several keynote talks, panel discussions and breakout groups, participants engaged in finding answers about how to establish a foresight mechanism that incorporates codesign between the science and policy communities. They drew on three nexus topics as a concrete starting point. For these important areas where tough choices will be likely, upstream research questions of high priority were identified to address challenges and research needs for SDG implementation over the next several years. Socioeconomic & biophysical dynamics of the humanity nature nexus: This topic addresses the economic paradigms, systems and business models that enable transitions to and preservation of a sustainable future. In this area, workshop participants identified research questions aggregated in five research clusters, two of which are listed below: ● Codesigning sustainable pathways that embrace biophysical and social systems dynamics ● Harnessing the power of businesses and providing SDGcompatible business model designs Food security & sustainable production and consumption ocean and land: Since this topic is interrelated with at least five of the SDGs, attaining a policy coherence will be challenging. In this regard, participants posited high priority research needs in several areas, including the following: ● Integrating environmental and ecosystem services into agricultural decisionmaking ● Informing a global regulatory framework to ensure food security