Glacial melt, as we have written many times, is a major threat in the long term to availability of water along the Peruvian coast. But in the short term it provides the water required to provide for Peru’s burgeoning cash-crop agriculture.

The Chavimochic irrigation and hydroelectric scheme is but one of several mega-projects designed to channel water to Peru’s desert plains. It has given rise to highly profitable agribusiness ventures, notably the cultivation of blueberries and asparagus, crops destined almost exclusively for export to China, the United States and European markets.

The agribusiness boom has stimulated large movements of peoples, mainly from peasant communities in the Andes, down to the coast where large new communities have grown up. Cash crop agriculture. and the packaging plants which go with it, have generated employment that, to some extent, has mitigated the acute poverty typical of many Andean communities.

Hydroelectric plants linked to irrigation schemes provide these communities with electricity, an element still lacking in many of the more remote Andean communities.

But all this is dependent on supply of water derived in large part from glacial melt. As the glaciers shrink in size, water will become an increasingly scarce commodity. Most rain falls on the Amazon side of the Andean divide. And as was the case in previous Peruvian cultures, lack of water hangs over peoples like a sword of Damocles. The benefits of short-term economic activity may prove illusory in the longer term.

The construction of projects like Chavimochic, which began back in the 1970s, has brought prosperity to modern agricultural businesses, but at huge cost to the Peruvian state which, ultimately, has had to pay the bill for the loans contracted to build them. And they have come as a boon for construction companies, such as Brazil’s Odebrecht, which have made a pile out of the contracts they have won, often (as we have seen) by bribing national and local politicians.

In Peru, there is perhaps justifiable pride in being able to harness climatic advantages (the availability of sunshine and the lack of a cold season) to diversify export production. Apparently, the blueberries produced are far bigger in size than those available from other producers, a feature that goes down well in China where they are much in demand. But this may prove to be an industry that is far from sustainable.

Glaciers continue to melt along the whole range of the Andes at a speed that is alarming to climate experts. When they finally disappear, so will the water supply that they are currently generating in such quantities. Meanwhile in the Amazon itself, rainfall is ever less plentiful, a factor that is causing the rain forest to dry up.

Peru is rated one of the countries most exposed to the effects of climate change.

A piece in the New York Times illustrates the problem of unsustainable agriculture. Though this is not a new article – it was published two years ago– the problems it highlights are just as relevant today as when they were written.