On this International Day of Peace, let us dare to imagine a world free of conflict and violence

Contrary to popular belief, we do not face a choice between economy and ecology, It is often said that protecting the environment would constrain or even undermine economic growth. In fact, the opposite is true: unless we protect resources and the earth's natural capital, we shall not be able to sustain economic growth.

Having worked my way from the bottom of the ladder to the top [of the UN] certainly helped me navigate that complexity, both political and bureaucratic.

Invite politicians to dinner and let them tell the world how delicious it is. . . . They will proudly go around and say, 'I ate crickets, I ate locusts, and they were delicious.'

Over time you learn to know a bit more about yourself - you develop a certain amount of self-insight and self-awareness, and you know what you can absorb, and what you cannot; what gets to you and what doesn't. And I observe a lot. I see a lot around me. And over time you also get to understand the nature of man and the environments you are dealing with, and you can't always allow emotions and temper to flare up because you're displeased with something, or you want to change it.

We have to be very clear with the population and the countries we enter what we can do and what we cannot do.

Fierce national competition over water resources has prompted fears that water issues contain the seeds of violent conflict.