THE Okavango Delta is unlikely to dry up in a lifetime, but new research showed the world’s only inland delta was likely to get smaller, University of Cape Town (UCT) Climate System Analysis Group research associate Piotr Wolski said on Thursday.
The delta is Botswana’s major tourism revenue source, bringing in millions of dollars a year.
Dr Wolski was speaking after UCT released the results of research in which he and UCT climatologist Bruce Hewitson collaborated with researchers from the US’s Lawrence Berkeley National Laboratory and the United Nations Development Programme on how human-induced climate change had affected recent flooding in the delta, and the ecologically and geographically unique river basin.
It is often difficult to directly link specific events to climate change.
The annual Okavango floods of 2009, 2010 and 2011 were "pretty dramatic", reaching extents last seen decades ago, and while deaths were minimal, villages and houses were flooded, bridges closed or washed away and water and electricity supplies interrupted, raising the question of whether they were caused by human-induced climate change, Dr Wolski said.
The researchers used computer modelling to come up with an answer and found the global increase in greenhouse gas emissions had "substantially reduced the chance of floods".
The study, which claims to be the first of its kind carried out in Africa due to the unique set of computer simulations created, compared a changed climate with an unchanged one.
"The air is warmer in the climate we are experiencing and the river takes a long time to flow down to the delta, so you get more evaporation occurring before the river even reaches the delta, and thus fewer high floods," said Dr Wolski.
Read more http://www.bdlive.co.za/national/science/2014/03/27/okavango-delta-unlikely-to-dry-up-in-a-lifetime-research-shows