‘Carbon footprint’ – the legacy of carbon released into the atmosphere that we leave to our descendants, the people and the planet of future times – is a term we have become familiar with over the past three decades as the science of climate change has moved out of the labs and pressure group handouts into common civic understanding, if not yet common civic action. It perfectly captures the idea that long after we have passed by, the impact we made on the planet and its biochemical systems remains.
The haunting metaphor of the ‘footprint’ – which brings to mind those massive dinosaur prints preserved in stone as a record of their time, millions of years ago – has also been applied to the legacy of a variety of other aspects of human consumption and waste, not least our use of water. New Scientist recently covered current thinking on the ‘water footprint’ in a two page interview with Arjen Hoekstra, a Dutch professor of water management (click here ).
Of course, here in Scotland, we have no shortage of water, so it’s hard for us to imagine that however much we use we are going to have a negative impact on human life in the future, but our ‘water footprint’ is not just what we consume in our own homes, gardens and work. A large part of our ‘footprint’ is elsewhere, left by the production in other parts of the world of the goods we consume here. Three quarters of the water footprint of people who live in the UK is outside the UK, in the countries where the goods and food we consume originate. Whereas our water cycle as an island on the edge of the Atlantic ensures that whatever we put back into the rivers and water table from our use of water will eventually fall back down on us (in fact climate change projections suggest parts of the UK will be wetter longer term in the future), in many parts of the world, water reserves used in agriculture are not being replenished. Around 90% of humanity’s global water footprint comes from food production and around a third of that comes from animal feed production. So next time you’re checking those food miles, and the contribution they make to your carbon footprint, just add in your water footprint as well.