The document discusses the concepts of environment and sustainable development. It provides definitions of sustainable development from the Brundtland Commission report in 1987. The key principle of sustainable development is integrating environmental, social and economic concerns into decision making. Bangladesh faces many environmental challenges including degradation of natural resources, pollution, and climate change impacts. The country has developed policies and strategies to protect the environment but continues to face threats such as habitat loss, species extinction, and degradation of forests and biodiversity hotspots. Regional cooperation is needed to address issues like protecting the Sundarbans mangrove forest from climate change impacts.