Aspects of the present disclosure relate to sustainability-aware computing device behavior management. In examples, a sustainability platform obtains sustainability information associated with an energy grid, as may be provided by a data provider. The sustainability platform may provide a sustainability forecast, which may be received and cached by a computing device. The computing device may use the sustainability forecast to manage various device functionality, such that functionality may be performed during one or more times that are identified to have a comparatively lower environmental impact, thereby deferring device energy consumption during a time forecasted to have a higher environmental impact. The sustainability forecast cached by the computing device may be updated on a periodic basis or in response to determining that the location of the computing device (and, potentially, the associated energy grid) has changed, among other examples.