The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. Established in 1948, WHO is headquartered in Geneva, Switzerland, and works with 194 member states across six regions. The organization is dedicated to promoting health, keeping the world safe, and serving the vulnerable by coordinating responses to health emergencies, promoting health and well-being, and ensuring universal health coverage.

WHO's work is guided by the principle that all people should enjoy the highest standard of health, regardless of race, religion, political belief, economic or social condition. The organization sets international health standards and guidelines, and provides support to countries in implementing health policies and programs.

In terms of sustainability, WHO is committed to reducing its environmental impact and promoting sustainable practices in health care. The organization has been involved in initiatives to address climate change and its impact on health, recognizing the importance of sustainable development in achieving health goals. WHO supports the integration of environmental health into public health policies and practices, although specific details on its carbon footprint or sustainability certifications are not extensively documented.

WHO's efforts in sustainability are part of a broader commitment to the United Nations' Sustainable Development Goals (SDGs), particularly Goal 3: Good Health and Well-being, and Goal 13: Climate Action. The organization encourages the health sector to adopt sustainable practices and reduce its environmental footprint, promoting the use of renewable energy and sustainable resources in health care facilities.