Faced with the crisis related to climate change and sustainability, we need to reflect on its relation with technology. This chapter discusses the nexus of environment and technology in two ways: it links to questions regarding modernity and the Anthropocene (ecomodernism vs. less modern thinking) and it discusses some practical examples of ambiguous relations between technology, sustainability, and climate change: geoengineering as a way to deal with climate change, environmental robots for sustainability, and AI for climate. The latter topic is elaborated with a practical example of how to manage software development (sustainability budgets) and with the case of energy use of training large language models. The discussion regarding technology in the Anthropocene and in the context of modernity is further developed with the case of geoengineering of volcanos.