For the past 38 years, Professor Primack, his students and colleagues have been studying long-term research plots in species rich rain forests on the tropical island of Borneo. In a recent article in Nature Communications, Primack and numerous colleagues show that these forests are increasing over time in tree biomass, and are therefor absorbing some of the atmospheric carbon dioxide that contributes to climate change. However, when forests are damaged by human activity, then the forests decline in biomass. These forests will continue to increase in scientific value in coming decades as the intensity of human impact on the environment increases. This article has also been featured in a Nature Communications online collection titled Forests in the Anthropocene.