Through integrative assessment, experts evaluate the state of knowledge and its limits on complex problems relevant to societies. Over decades, assessment by the Intergovernmental Panel on Climate Change and many others has bolstered understanding of the climate problem: unequivocal warming, pervasive impacts, and serious risks from continued high emissions of heat-trapping gases. Societies are increasingly responding with early actions towards decarbonizing energy systems and preparing for impacts. The emerging era of climate solutions presents compelling assessment opportunities. They include learning from ongoing real-world experiences and helping close the gap between aspirations and the pace of progress. In this presentation, I will consider past experiences and future possibilities for core challenges in assessment: (1) integrating diverse evidence, especially quantitative and qualitative understanding; (2) applying rigorous expert judgment; and (3) deeply embedding interactions between experts and decision-makers. For climate and broader global change, integrative assessment can support decisions about contested and uncertain futures. I will reflect on practices for advancing transparent assessment with traction. Examples will span climate risks and portfolios of mitigation and adaptation responses.