Digital technologies have substantial environmental impacts. The EU’s 2022 Digital Services Act (DSA) requires the largest platforms and search engines to regularly assess “systemic risks” to various social interests – including public health, physical wellbeing, security, and fundamental rights – and to reasonably and proportionately mitigate these risks. Climate change and other escalating environmental crises severely threaten these interests. Accordingly, this policy brief argues that the DSA requires these companies to take reasonable measures to reduce their environmental impacts. This should notably include following best practices to minimise energy and water usage, including “sustainability by design” obligations to pursue less energy- and resource-intensive technologies, design choices, and business practices wherever possible. It should also include measures addressing platforms’ indirect environmental impacts, such as the facilitation of environmentally-damaging behaviour by third-party businesses. Since the DSA’s risk mitigation obligations apply specifically to the largest platforms – which exercise significant influence over broader technological and commercial ecosystems – regulatory pressure on these companies to take such measures could have outsized environmental benefits. This policy brief by Rachel Griffin, PhD candidate at Sciences Po Law School, offers a legal analysis of the DSA’s relevance to environmental policy and explains why environmental risks are within its scope. It then outlines appropriate measures to mitigate platforms’ direct and indirect environmental impacts. It concludes with recommendations for platform companies, regulators, and civil society on how to realise the Digital Services Act’s potential to help secure a more sustainable tech industry.