Water has been an essential commodity for as long as humanity has existed. So critical is water to all life that wars have been fought over its supply for millennia. And yet, much of the world still takes water for granted, even in the face of a global warming crisis.

Believe it or not, I came very close to leaving Toronto without photographing Niagara Falls. The weather forecast was for heavy rain, and I would need to go at a crazy hour to reach the falls in time for sunrise. But a break in the storm allowed me to experience a moment which will stay with me forever.

With flash floods, freak storms, and record-breaking heat waves every year, is it time to recognise that climate change is real and we all have to play our part in reducing our impact on the earth? Scott Poynton of The Pond Foundation certainly thinks so.

Exhausted from days of sleep and oxygen deprivation, I stood staring up at the summit of Kilimanjaro and wondered, for the first time, whether this would finally be a challenge too far.