The God Species_ How the Planet Can Survive the Age of Humans - Mark Lynas [76]
Due to the globe-girdling reach of modern human civilization, these regional and planetary-scale changes are perhaps unsurprising, for humanity has always had an umbilical connection with rivers and fresh water. Imperial capitals throughout history have lined major watercourses, from Nanjing on the Yangtze to London on the Thames. When water became scarce or was misused—as in ancient Mesopotamia or during Central America’s Classic Maya period—great civilizations could come crashing down, leaving little trace behind as their once unconquerable cities were reclaimed by sand or forest. Today we face the danger of overusing water resources on a planetary scale, and the consequences for our advanced civilization may be just as significant in the long run.
TURNING ON THE TAP
It would be foolish to neglect the enormous benefits that water engineering and control have delivered to humanity. Our domination of the water cycle, as with our rule of the land, has given the human species in the industrial era advantages that would once have been unimaginable: unlimited clean, fresh water, literally “on tap” and delivered wherever and whenever we need it. For most of human history, and still today in poorer parts of the world, water had to be fetched and carried—usually by women—and was a precious and limited resource. Clean water could never be guaranteed, and as human populations began to rise after the Middle Ages, epidemics of waterborne diseases like cholera became a chronic danger for anyone living in the booming, crowded cities. That whole civilizations can now flourish in desert areas that experience little or no direct rainfall is a tribute to human ingenuity and the mastery of complex hydrological engineering over the vagaries of nature. That we have in large part managed to tame the water cycle—capturing water so that we can have it when we need it, rather than waiting for it to fall from the sky—is a key element of the human domestication of our planet and surely one of our greatest successes as a species.
Indeed, one of today’s most urgent challenges is to bring these advantages—of clean and plentiful water—to the entire world’s population. Anyone who cares about children should care about clean water, for every day 6,000 children (mostly under the age of five) die from preventable diarrheal diseases linked to dirty water and bad sanitation, and many more from malaria and other water-related diseases. Globally, 1 billion people lack access to an improved water supply, and 2.6 billion lack access to improved sanitation. A pledge to halve by 2015 “the proportion of people without sustainable access to safe drinking water” is one of the most important of the UN’s Millennium Development Goals, and although globally the target is likely to be met, one of the regions that is still falling behind is sub-Saharan Africa, where most water and disease-related deaths of young children occur.
But hardly any progress has been made in meeting the associated Millennium Development Goal on sanitation, and current projections suggest that two thirds of the world’s population will still not be connected to public sewage systems even by 2030: a grim indictment of our current lack of commitment in this vital area. For those more moved by economic logic than by thousands of daily avoidable childhood deaths, the benefits of investment are still overwhelming: For each $1 invested in improving water supplies, the World Health Organization estimates annual returns of between $3 and $34—rates most commercial investors can only dream of.8
Fresh water is vital not just for drinking but also for food production. The increasing use of irrigation in agriculture was one of the most important benefits of the Green Revolution, which began in the 1960s and—by bringing