Both developed and developing countries face many environmental challenges, including climate change, improving energy efficiency and waste management, addressing air pollution, water quality and scarcity, and loss of natural habitats and biodiversity. Drawing on the existing literature, this paper explores how the Internet and ICT can help tackle environmental challenges in developing countries through more environmentally sustainable models of economic development and environmentally friendly technologies and applications. This review focuses on the role of ICTs in climate change mitigation, mitigating other environmental pressures and climate change adaptation, providing an overview and pointing to examples of current activities and opportunities in each of these areas.