Indo-Asian News Service: Twenty five percent of Africa experiences shortage of drinking water due to global warming, which is increasing at a higher rate now than in earlier decades, says noted environmentalist R.K. Pachauri. "Climate changes due to greenhouse gas emissions will only exacerbate. More intense and larger droughts will be there. Twenty five percent of Africa and its population will experience high water stress," Pachauri said while delivering through video clip a lecture on "The environment and …