Determining how climate change will affect global ecology and ecosystem services is one of the next important frontiers in
environmental science. Many species already exhibit smaller sizes as a result of climate change and many others are likely to
shrink in response to continued climate change, following fundamental ecological and metabolic rules. This could negatively
impact both crop plants and protein sources such as fish that are important for human nutrition. Furthermore, heterogeneity in
response is likely to upset ecosystem balances. We discuss future research directions to better understand the trend and help
ameliorate the trophic cascades and loss of biodiversity that will probably result from continued decreases in organism size.