Sustainable development goals aim to improve the living conditions, health, education, work conditions and ecosystems of the planet, both on land and at sea. But, as Ed Gould asks, what are they exactly and how do they function?   It was under the leadership of Ban Ki-moon, the former Director-General, that the United Nations adopted a comprehensive programme of sustainable development goals, or SDGs as they are sometimes called. They built upon a previous framework for sustainable dev