Climate change is impacting ecosystems in multiple ways, including changing the composition, diversity and abundance of biological communities. These changes in ecosystem structure impact the functions and services that ecosystems provide and therefore threaten human well-being. At the same time, biodiversity, and other aspects of ecosystem structure, are key to promoting the stability of ecosystems in the face of climate change and may further help mitigate climate change. In this cluster, we investigate how climate change affects ecosystems, identify the structural attributes that support stable ecosystem functioning and services under climate stress, and explore how ecosystem organization may feedback to mitigate climate change. We study these interactions at multiple scales, from short-term processes operating at the scale of individual cells to long-term and large-scale processes occurring across the globe. We use experiments, modelling, and comparative methods to understand how climate change has influenced ecosystems in the past and to predict its future impacts on ecosystem structure and processes.