domingo, 29 de maio de 2011

A solution to reverse Africa's growing deserts

Groasis, an ingenious passive 'water incubator' collects dew drops, making reforestation in barren lands possible.

Fri, Apr 16 2010 at 4:33 AM EST

Photo: Pieter Hoff/Groasis
I've often said that the most sophisticated "green" technology on the planet is the humble tree. Trees sequester carbon, fix nitrogen into the soil, create organic compost, prevent erosion and encourage rain, while providing sustainable crops, shape, lumber and even fuel. The single most important activity on the planet (I believe) is planting trees, a fact backed up by the latest McKinsey study on abating the effects of global warming. But there is a problem.
 
Reforestation efforts in denuded lands such as Africa, Mexico, India and China have never been taken seriously as a means to abate climate change because young saplings are very difficult to establish. They take a lot of water and require regular maintenance — two things that are in scarce supply in precisely the regions where they are needed most.
 
But what if there were a device that eliminated those risks? A device that requires no power source, has no moving parts and literally conjures water out of the air? It sounds like a miracle, but that miracle may be upon us with the advent of the Groasis Waterboxx.
 
This simple passive water-harvesting device takes advantage of one attribute that most deserts have — a major temperature differential between night and day.
 
Dew is created at night when the tiny amount of moisture in the air condenses on semi-permeable surfaces like leaves. As soon as the sun rises, the dew quickly burns off and returns back to the air. But the ingenious little Waterboxx channels the dew to a collection tank where it helps the young roots of a sapling get established. 
 
Eventually the roots become strong enough to seek their own water deep underground.
 
Pieter Hoff, the Dutch inventor of the Waterboxx, recently completed a study in a desert in Morocco. The results were astonishing. With next to no care whatsoever, 100 percent of the trees in a Groasis Waterboxx survived, and nearly 90 percent were thriving. Contrast that with a standard tree-planting effort in which only 10 percent of the trees survived.
 
Likened to a "water battery," the Waterboxx is a passive drip irrigation system, slowly wicking a trickle of the water it collects into the tree's fledgling root system. 
 
While there is no doubt that our #1 environmental priority is to prevent further deforestation — the leading cause of greenhouse gas emissions — the Groasis provides a glimmer of hope on the horizon for preventing climate change (while restoring water supplies and building soil fertility) in regions that seem beyond hope. 
 
Note: The current Waterboxx is made out of polypropylene, but the company is working on a biodegradable version that decomposes as soon as roots have been established.