Last year on Climate Feedback, Kevin Vranes wrote about some of the unintended consequences of climate policy – namely how the Kyoto Protocol’s Clean Development Mechanism was increasing greenhouse gas emissions through the burning of HCF-23 in developing countries – as well as increasing ozone-depleting chemicals in the atmosphere.

Now, the drive to tackle climate change – and fast – has landed us back in the land of unintended consequences, though for a whole host of other reasons.

A few particularly noteworthy examples have come across my radar in the past couple of weeks.

First up, is the increasing demand from alternative energies on the world’s water supplies, a factor not helped by the complete lack of cohesion between energy, water and climate policy. A prime example, as reported by Brian Hoyle on Nature Reports Climate Change, is the extensive irrigation required for those waving fields of midwest grain that supply the ethanol for biofuels.

“At least 40 gallons [of water] go into every mile travelled by an ethanol-powered vehicle” according to Michael Webber of the Center for International Energy and Environmental Policy, University of Texas-Austin.

And gas-electric hybrid vehicles fare little better. “We need to move from our old way of thinking — miles per gallon — to gallons of water per mile," says Webber.

Not only do these golden fields of corn pose a threat to water supplies, the massive amounts of fertiliser used in growing them are increasing nitrogen run-off into the Gulf of Mexico and worsening the existing ‘dead zones’ in the Gulf associated with fish kills. The paper, published in Proceedings of the National Academy of Sciences , notes that this is in direct conflict with existing policy targets to reduce the oxygen-depleted area in the region.

And on an unrelated topic…the trail of unforeseen outcomes continues overseas…as highlighted last week in The Washington Post, which reported the toxic waste being left behind by solar energy companies in China, posing a severe threat to human health.

As much as climate policy is urgently needed, it seems it would be worth remembering that climate is not the only sustainability issue.

Olive Heffernan