The article is devoted to the analysis of environmental and legal problems caused by the war in Ukraine, which should be considered comprehensively, as environmental security issues can easily transform into social threats. The article proves that the pollution caused by the war has a significant negative transboundary impact, in particular, the Russian invasion has not only damaged the environment of Ukraine, but also threatened the achievement of climate goals and even the world's ability to adapt to climate change. The purpose of the study is a comprehensive study and analysis of national and international environmental, humanitarian and criminal law through the prism of modern environmental challenges and threats. In this regard, the methodological basis of the article is a set of general philosophical, general scientific, special scientific and legal methods. The paper also analyzes the impact of modern threats in the field of environmental security on the state of national security, as well as the state of implementation of measures in the field of environmental security. Based on their own conclusions and generalizations, the authors' proposals and recommendations for improving the current national legislation and greening the sectoral components of national policy are presented.