Could Namibia Become Even Drier in the Future?

PUBLISHED 13 MAR 2018   

More than a quarter of all land on the planet is at risk of becoming significantly drier if the atmosphere warms by 2 degrees C, a new study conducted by an international team of climate scientists has revealed. This would in turn increase the risk of drought and wildfires in these regions.

 

However, according to the study, which was recently published in Nature Climate Change, keeping global warming under 1.5 degrees C would reduce the area of land surface threatened by these changes by two-thirds.

Aridity is the term used to describe the dryness of a land surface. It is a measurement that is derived from combining the amount of precipitation and evaporation. The scientists analyzed projections from twenty-seven global climate models to pin-point areas around the world that were likely to become more arid as the world becomes 1.5C and 2C warmer than it was before the industrial revolution.

Aridification poses a serious threat to humanity because it can affect water quality, agriculture and biodiversity — all of which are important to Namibia's long-term sustainability. An increase in aridity can also lead to an increase in droughts and wildfires, as we have recently witnessed in California.

"Another way of thinking of the emergence of aridification is a shift to continuous moderate drought conditions, on top of which future year-to-year variability can cause more severe drought," explains study co-author, Dr Chang-Eui Park from the Southern University of Science and Technology (SUSTech) in Shenzhen China. "For instance, in such a scenario 15 per cent of semi-arid regions would actually experience conditions similar to 'arid' climates today."


"The world has already warmed by 1C," says Dr Su-Jong Jeong from SusTech. "But by reducing greenhouse gas emissions into the atmosphere in order to keep global warming under 1.5C or 2C could reduce the likelihood of significant aridification emerging in many parts of the world."

Several regions including southern Africa, the Mediterranean, and Australia's east coast have been seen an increase in drought severity in recent times, while semi-arid regions of southern Africa, Australia, Brazil and Mexico have experienced an increase in desertification as the world has become warmer. 

According to Prof Tim Osborn from the University of East Anglia, there are five regions that would benefit the most from keeping global warming below 1.5C. These include Southern Africa, Southern Australia, Central America, South East Asia and Southern Europe, which are collectively home to 20% of the global population, effectively putting a fifth of the world's inhabitants at risk. 

Considering that Namibia is already an arid region covered largely by desert, this provides a good incentive to support clean energy initiatives, such as solar, that reduce greenhouse gas emissions responsible for global warming.

Journal Reference

Chang-Eui Park, Su-Jong Jeong, Manoj Joshi, Timothy J. Osborn, Chang-Hoi Ho, Shilong Piao, Deliang Chen, Junguo Liu, Hong Yang, Hoonyoung Park, Baek-Min Kim, Song Feng. Keeping global warming within 1.5 °C constrains emergence of aridification. Nature Climate Change, 2018; DOI: 10.1038/s41558-017-0034-4