A future of floods and droughts as climate changes. World Bank
Rainfall varies naturally from year to year and from decade to decade, influenced by the El Niño-Southern Oscillation (ENSO) and other climate drivers.
In addition to natural climate variability, climate change caused by greenhouse gas emissions will have an increasing impact on the water cycle. According to the Intergovernmental Panel on Climate Change, the contrast in precipitation between wet and dry regions and between wet and dry seasons will increase during the 21st century.
Wet areas will become wetter, and dry areas drier. The extent and speed of these changes will depend on whether we achieve the target of keeping temperature increases to less than 2°Celsius above the pre-industrial era.
Temperature increases above the 2°C limit will mean more water stress. Scenarios by the World Bank suggest that in a 4°Celsius warmer world, roughly 1 billion people living in monsoonal basins and the 500 million people living in deltas are especially vulnerable. Poorer countries, which contributed least to the problem, will be most affected. http://www.worldbank.org/en/topic/water/overview
Population increase, rising water usage by sectors like agriculture and pollution add to the challenges of water management regardless of the amount of rainfall.
Too little precipitation leads to droughts. These affect more people than any other kind of natural hazard owing to their large scale and long-lasting nature.
During the 21st century, drought in East Africa in 2004 and 2005 resulted in widespread loss of life and food shortages. A drought in 2010-11 contributed to famine in Somalia which was responsible for approximately 258,000 excess deaths. according to the Famine Early Warning Systems Network.
The 2011–2015 period featured multi-year droughts, including Brazil, Southwestern United States of America (USA) and eastern Australia.
The arrival of El Niño in 2015 brought significant droughts to many parts of the world. These included southern Africa and Ethiopia, Indonesia – which also suffered from severe forest fires – the islands of the western South Pacific, Central America and the Caribbean, and parts of the Indian subcontinent.
2015 at a Glance