Water scarcity problems are likely to worsen because of climate change, and the world is not doing enough to address the challenges, according to the head of a United Nations panel of climate scientists.

The latest report from the U.N. Intergovernmental Panel on Climate Change (IPCC) predicts a rise in global temperature of between 0.3 and 4.8 degrees Celsius (0.5 to 8.6 degrees Fahrenheit) by the end of the 21st century.

Global warming will bring more severe weather events, including droughts that will cause serious water shortages and affect agricultural output and food security. The scarcity of water in some regions could lead to conflict between communities and nations.

"Unfortunately, the world has not really woken up to the reality of what we are going to face in terms of the crises as far as water is concerned," IPCC Chair Rajendra Pachauri told delegates at a conference on water security.

Pachauri explained that agricultural activity will be significantly affected by water shortages. For instance, demand for animal meat has been growing, but caring for livestock is highly water-intensive. Dramatic changes in the water cycle brought about by climate change mean that water supply will be unable to keep up with the demand.

It's essential to make use of new technology to help use water more efficiently, particularly in agriculture where there is a lot of waste, Pachauri said.