This rapid review synthesises the literature on the environmental risks of four different aspects of digital transformation in developing countries: ICT adoption, digitally-enabled energy efficiency, ride-hailing apps, and big data use. The overall message which runs throughout the diverse literatures and results is that it is not digital technologies that create environmental risks or opportunities, but how they are used. Efficiency gains derived from digital transformation may yet lead developing countries down existing unsustainable development paths if not accompanied by careful, context-dependent policy. For policy-makers seeking to mitigate environmental risks, this means putting the context of digital use at the centre of analysis rather than the technologies themselves. However, the research literature covers more specific aspects of digital transformation. In practice, this report defines digital transformation as: ICT adoption, digitally-enabled energy efficiency, ride-hailing apps, and big data use. These topics were chosen after an initial scoping review of available literature, and because they exemplify a range of the different types of potential digital effects. The literature on the environmental risks of digital transformation is huge and conflicting. This is problematic because it could be easy to cherry pick preferred research results. Several studies noted that there is less research on developing countries than developed countries, but the evidence base is still large. As an evidence review, this report focused on the academic literature, but there is also a large grey literature. Some of the literature has a gender aspect, not covered in this report.Foreign, Commonwealth & Development Office (FCDO)