I learned two basic lessons on Everest. First, just because something has worked in the past does not mean it will work today. Second, different challenges require different mindsets.

If we pass on an unsustainable environment to our children we have failed them.

The right to have our environment protected for the benefit of present and future generations is our most important human right.

The blues is also existential and offers a sense of mature reflection that enabled it to be the leitmotif of modern life.

The days of exploration of Shackleton and Scott are long gone. Everything has been climbed, crossed, done. Now what we're exploring are the full boundaries of human endeavour. It's not physical - it's all in the head.

I learned two basic lessons on Everest. First, just because something has worked in the past does not mean it will work today. Second, different challenges require different mindsets.

Climate change is the Everest of all problems, the thorniest challenge facing humankind.