 Researchers have created a new computational model to investigate how various marine species will relocate in response to climate change over the next century. As ocean temperatures rise and marine species move to new geographic regions, the model predicts that biodiversity will increase in some areas, bringing together species that have never before shared a habitat. This study highlights the urgency of mitigating climate change and suggests regions that warrant particularly intensive conservation efforts. To construct this model, the researchers started with the present-day geographic ranges of 13,000 marine species 12 times more than any previous study. They also mapped the predicted changes in sea surface temperature over time under two climate change scenarios. These two data sets were then combined to determine where and how quickly the studied organisms will migrate, assuming that the marine species will relocate to avoid dramatic changes in the temperature of their environment. The results show that biodiversity will decrease in many areas, particularly the tropics, but increase in others. In areas of increased biodiversity, the arrival of new species will strongly affect the original inhabitants, providing new prey, predators, and competitors. Ultimately, many of the oceans' communities will become more similar to one another, increasing their vulnerability to the effects of ecological changes. For example, because diseases spread easily among similar communities, this community homogenization will increase the amount of damage that a single disease can inflict on the ecosystem as a whole. In the future, the results of this study may help conservationists and policymakers identify areas where managing the interactions between invading species and native species may be particularly challenging. International collaboration will be critical because the relocation of, for example, fish stocks, emblematic species, and nuisance species will cross jurisdictional borders. Therefore, the management and conservation of these species will need to shift from the traditional, local, or national-scale focus to more global efforts.