"The combined impact of climate change, land mismanagement and unsustainable freshwater use has seen the world’s water-scarce regions increasingly degraded. This leaves their soils less able to support crops, livestock and wildlife. This week, the Intergovernmental Panel on Climate Change (IPCC) will publish its special report on climate change and land. The report, written by hundreds of scientists and researchers from across the world, dedicates one of its seven chapters solely to the issue of desertification."The 30 year climate map illustrates the geographies involved (plus see also Koppen climate maps)... In this light, it's worth inverting the issues and seeking opportunities in such drylands. The big technological achievements of the past half-century are solar power and desalination. But there's more, including much greater sophistication around water use, shades of greywater, cycling, and design and landscaping for water retention. Furthermore, reforestation, for instance in the Sahel, has been done with hardier plant varieties and is increasingly including soil modification or assistive techniques to both preserve water and make maximum use of every little bit. On arid but foggy coasts (e.g. Atacama, Namibia, etc) inexpensive materials are boosting the effectiveness of fog harvesting. And we can learn from classic desert cities and ancient techniques (e.g. Petra, the medinas, etc) about greening the desert. In any case, when you stitch all the existing and emergent ideas together, I believe there's a blossoming new category of "oasis cities" in arid regions.
22 November 2019
The WEF writes about Desertification: what is it and why is it one of the greatest threats of our time?
04 November 2019
The BBC spotlights Concerns over increase in toxic brine from desalination plants...
"Desalination plants around the world are pumping out far more salt laden brine than previously believed [...] The salty effluent is a by-product of efforts to extract fresh water from the sea. [...] The brine raises the level of salinity and poses a major risk to ocean life and marine ecosystems. [...] There's been a major expansion of desalination plants around the world over the past few years, with almost 16,000 now operating in 177 countries. It's estimated that these plants produce 95 million cubic metres of freshwater per day from seas and rivers -- equivalent to almost half the average flow over Niagara Falls. But the success of the technology is coming at a price. This new study estimates these plants discharge 142 million cubic metres of extremely salty brine every day, a 50% increase on previous estimates."All challenging and yet therein also lies opportunities, including the mining and refinement of salts, minerals, and metals.