Wednesday, August 18, 2010
Does global water shortage lead to new demands for energy?
In partnership with Energie-Fakten.
Is water becoming scarce? An evening debate at the Foundation for Energy and Climate Protection Baden-Wuerttemberg was dedicated to the theme of water scarcity. Prof. Dr. Klaus Töpfer opened the debate.
Water is of great importance for industrial and emerging countries alike, but 1.2 billion people lack access to clean water and every 20 seconds a child dies because of unhealthy water. World population is expected to increase from 7 billion today to a projected 9 billion in 2050. Since water consumption is growing twice as fast as world population, these 9 billion will need today’s average water consumption of 12 billion people. It is correct that 70% of the earth surface is water, but over 97% of this is salt water in the oceans. Except for cooling purposes, it is not directly suitable for human use. The fresh water reserves are very unevenly distributed across the world. Already, the global imbalance in the availability of water has led to large migration movements and in the future, it could very well come to war over access to clean water.
Water must therefore be used more intelligently, especially in agriculture, which takes an average of 70% of water use in a country.
In Germany, water use is approximately 127 liters per person per day. But that number is deceptive, because many imported products carry already an indirect use of water through manufacturing. For example, the "production" of 1 kg of beef needs about 15,000 kg of water. Fresh water has already become an international trade commodity. Turkey has started to export water in tankers to other countries of the Middle East. But trade alone can not solve the problem. More and more countries are reliant on freshwater supplies from seawater desalination plants. These systems are predominantly based on thermal processes, while the energetically favorable alternative of reverse osmosis is still in its infancy. By far the largest sea water desalination capacity is currently operating in the Middle East, but with Malta and Spain, the EU has already two members partially dependent on seawater desalination. In many regions of the world, seawater desalination represents a new sector for energy demand that is growing fast. Because fresh water is a fundamental right and its supply is limited. Future energy concepts and technologies must therefore be focused on possible approaches for integrated seawater desalination.
Climate change could further exacerbate the water problems in many parts of the world. While the climate models generally agree on global trends, regional effects are much less understood. There can be significant regional deviations from these global trends with significant effect on rainfall. Particularly in vulnerable regions, adaptation measures need to be initiated, because water is fundamental for poverty reduction.