Data science holds extraordinary promise for better policymaking for humans and the environment while at the same time posing myriad harms. Data science helps draft solutions to many human-environment problems, including climate change, environmental degradation, and sustainable development. It also has many troubling aspects. It is reshaping many human activities in ways that can increase their negative environmental impacts. It is remaking many facets of society, including injuring privacy, increasing surveillance, and negatively affecting people’s lives. In response to these actual and potential issues, there is growing interest in developing scientific, legal, and policy mechanisms to protect sensitive environmental areas, expand open science, and address concerns around privacy, choice, and other social impacts of big data. Many of the policy dilemmas and solutions around data science are brought into sharp contrast by its application to achieving sustainable development goals worldwide.