He also says drinking water and ice is finally reaching some of the ravaged coastal areas and other critical supplies are on their way.

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To put that figure in context, Iannelli says that the energy required to pump freshwater from underground (which, he says, is the most common source of drinking water in the West) typically produces just over 1.5 tonnes of CO2 per million gallons.

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Drinking water protection is also a concern in some areas, he said.

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He says that while it is unlikely that residents will be using the river directly for drinking water, it may pose a problem for water companies.

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'The Icefield is said to feed up to 80 per cent of Canada's drinking water, ' he says, 'but most of this glacier's volume has been lost since the 1920s.

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"Cholera can be treated quickly and people can get better quickly but the challenge is ensuring they don't get re-infected and clean drinking water needs to be available, " he said.

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