It is by now a commonly accepted fact that the next world war, if it comes, will be fought over water. While our planet is 70 per cent water, scientists say that it will not be enough in the future to sustain the billions.
Humans are drawing down the resource too quickly for it to be replenished, which could lead to conflict and natural catastrophes, experts said recently at the 15th Isaac Asimov Memorial Debate, held at the American Museum of Natural History in New York City. Scientists, however, have a few crazy tricks up their sleeves to deal with the coming water crisis, from bagging water-rich comets to building water-filtration plants on Mars, researchers said.
Scarce resource
Scientists now think Earth first received its cache of water a few billion years ago, when the solar system was still forming. At that time, the snowball planets Uranus and Neptune switched places, sending a whole bunch of icy debris in their orbits careening straight towards Earth, said Heidi Hammel, executive vice-president of the Association of Universities for Research in Astronomy.
Humans are drawing much of that drinkable water out of the ground at an unprecedented rate. For instance, the groundwater in the aquifer under the Gaza Strip will be completely used up in two years, said Charles Wald, a retired US Air Force general. When people run out of water, things get ugly, Wald said at the Asimov debate, adding that the conflict in Darfur, Sudan, was largely between pastoralists and nomads over water rights.
Recycling in space
For instance, NASA is always working to devise more efficient ways to recycle water on spaceships. After all, reusing water means spacecrafts don’t have to lug the precious resource into outer space, Stofan said. On Earth, people already treat a small fraction of used water, called wastewater, but most of that water either gets washed into the ocean or is used for non-essential purposes, like watering golf courses. In the future, wastewater treatment could ramp up, and people may one day drink water that someone else peed in, experts said. “We’re going to have to use wastewater and recycle everything we have,” Wald said.
Radical solutions?
To solve these problems, scientists have proposed all of the usual solutions — more targeted irrigation, water recycling, desalination plants and smarter crop use.
Scientists have also developed novel ways for farmers to monitor their water usage. For instance, Nasa can now monitor exactly how much moisture is in soil with incredible resolution, thanks to a satellite called the Soil Moisture Active Passive. This technique could provide farmers with a much more accurate, real-time measurement of how much water their crops need, Ellen Stofan, chief scientist at Nasa, said at the debate. But for the long term, scientists have much more ambitious ideas. And they’re taking these ideas very seriously.
Grab a comet, drain Mars
NASA scientists, for instance, have proposed sending a rocket ship to an icy comet and bagging it; the comet would then be stored for future water harvesting. NASA is also actively working on a system that could filter water from beneath the surface of Mars, which likely has liquid water a few kilometers beneath its barren surface, said a scientist.
Though these ideas may sound far-fetched, many experts see them as more permanent solutions that will take 30, 40 or 50 years to develop. Addressing water scarcity in the long term will require “some space solution, no doubt about it,” Wald said.
