CBFS scientist teamed up with limnologist from Germany, France, UK, Canada, Switzerland, and USA (Vermont and Ohio) to study how phytoplankton and in particular cyanobacteria are affected by climate change and land use change in Europe and North America. Data from 1971 to 2016 on 29 focal lake basins and 1567 lakes across regions were analyzed, with Oneida Lake having one of the longer time series available. On average, lakes were expected to have higher phytoplankton due to increase in both temperature and urban land use and decreases in forested land. The importance of land use changes compared to climate change varied among regions, with lakes in urban areas mostly influenced by land use. Our quantitative analyses suggest local management measures should focus on retaining nutrients in urban landscapes to prevent nutrient pollution from exacerbating ongoing changes to lake ecosystems from climate change. The article was published in Global Change Biology this week and is available open source at doi.org/10.1111/gcb.15866.