Impacts of climate change on crop yields: what do we know and how do we know it? A decrease in global food availability is amongst the biggest concern about climate change and its impacts at local, national or global scales. Numerous publications have assessed the size of observed or future crop losses or gains under CO2, temperature or precipitation changes. This has been achieved through the use of experimental, empirical or modelling studies with the aim of identifying key sensitivities in cropping systems or practices that improve their robustness. These studies have provided results with large overlap but also some level of divergence due to the nature of the data, the processes taken into account or the type of assessment methods. In this presentation, I will present an overview of the impacts of climate change on crop yields worldwide with a focus on large-scale synthesis methods. On how climate change (should) modify our research activities The recent IPCC 1.5°C report, or more broadly the trove of alarming information on atmospheric and ecosystem rates of change in the recent years have sparked widespread concern in the society as exemplified by youth movements around the world. Citizens are faced with the accumulation of this evidence and the meaning of it for their lives or the ones of their children, on a daily basis. For a growing number of scientists this also results in changes in the way they perceive their own working practices or their role in the necessary transition of societies. To answer some of these challenges and make progress we have built a collective action to quantify and decrease the environmental footprint of research activities. I will present the aims and first results of our researcher-led campaign group called Labos 1point5 - in reference to the Paris agreement - which now gather over 800 scientists in a large range of disciplines in France.