We used biodiversity time series in the bioTIME database to dissect richness and turnover within and across communities, in space and time and across taxa. Change in community composition is emerging as the most evident way in which biodiversity is changing in the Anthropocene. Extinctions and colonizations, as well as changes in relative abundances of populations drive temporal turnover in ecological communities, and affect spatial patterns in β diversity. We found that colonizations and extinctions are accelerating but are approximately balanced. Most populations have no detectable trend in their abundances, and those that are changing are equally divided among those increasing and those decreasing in abundance. Temporal turnover in ecological communities is therefore the result of a balance between winners and losers. On average we do not detect a significant change in species richness, with many locations have decreasing and others decreasing richness trends. There are spatial patterns in this variation with the tropics and the marine realm emerging as hotspots of biodiversity loss.