DURHAM, N.H. --The entire water cycle of the globe has been changed by human
activities and even more dramatic changes lie ahead, said a group of experts at an
international conference in Amsterdam on global change this week.
"Today, approximately 2 billion people are suffering from water stress, and models predict that this will increase to more than 3 billion (or about 40 percent of the population) in 2025," said Charles Vorosmarty, a research professor in the University of New Hampshire's Institute for the Study of Earth, Oceans, and Space.
There will be winners and losers in terms of access to safe water. The world's poor nations will be the biggest losers. Countries already suffering severe water shortages, such as Mexico, Pakistan, northern China, Poland and countries in the Middle East and sub-Saharan Africa will be hardest hit.
"Water scarcity means a growing number of public health, pollution and economic development problems," said Vorosmarty.
"To avoid major conflict through competition for water resources, we urgently need international water use plans," added Professor Hartmut Grassl from the Max-Planck-Institute for Meteorology in Germany. "I believe this should be mediated by an established intergovernmental body."
The water cycle is affected by climate change, population growth, increasing water demand, changes in vegetation cover and finally the El Nino Southern Oscillation, bringing drought to some areas and flooding to others. Surprisingly, at the global scale, population growth and increasing demand for water -- not climate change -- are the primary contributing factors in future water scarcity to the year 2025.
"But at the regional scale, which is where all the critical decisions are made, it is the combination of population growth, increasing demand for water, and climate change that is the main culprit," said Vorosmarty.
According to El Nino expert, Professor Antonio Busalacchi from the University of Maryland, the two major El Nino events of the century occurred in the last 15 years and there are signs that the frequency may increase due to human activities.
"In 1982-83, what was referred to as the "El Nino event of the century" occurred with global economic consequences totaling more than $13 billion," said Busalacchi. "The recently concluded 1997-1998 El Nino was the second El Nino event of the century with economic losses estimated to be upward of $89 billion."
By Sharon Keeler
UNH News Bureau