How scarce is our water? An analysis of the present and future world water situation

If you look at the media, you come across new horror stories about water almost every day. Experts warn of a life-threatening global water crisis. Reports of droughts, wars for water, poisoned water and the end of our water resources are fuelling fears to die of thirst or of running out of water. How realistic is this news? Is this the truth or is this information the typical hype of the media where "only bad news is good news"? The presentation answers the question and gives an analysis of the global water scarcity. It describes the current water situation and makes a prediction up to the year 2050. In the first part the current water demand and water supply are presented with focus on the global water balance and today’s water scarcity. In the second part, the future water scarcity in terms of population boom, economic development, increase of living standards (urbanization, industrialization and change of diet), climate change, and non-sustainable water use is discussed. It is shown that our future water demand will increase dramatically until 2050, while our water supply will stay more or less constant. To close this gap, possible options are rather in an improvement of the water demand management than water supply management. That means that the water saving potential is much higher than the possible increase of the water supply. A key role plays the agricultural water consumption for irrigation which makes up the largest part of our water demand. Despite all the optimizations our water demand will increase until 2050. Therefore, it is very likely that in the future water and land resources for natural ecosystems will further decrease mainly due to the worldwide increase of agriculture. Additionally, adaption to climate change requires adaption to climate variability, stronger weather extremes, seasonal changes, and higher temperatures. The solution of the water problem requires the application of a wide spectrum of methods whereby the socio-economic obstacles are at least as critical as the technical challenges. The main question for the future still remains: How to share the world’s water resources in a fair way among its inhabitants?