Deserts are carbon-free powerhouses: Experts

They said an area measuring 800kmx800km of a desert, such as the Sahara, can capture enough solar energy to generate all the world's electricity needs and more.

This was stated in a thematic report of the United Nations Environment Programme (UNEP) on biological, economic and cultural dynamics of desert published last week, marking the World Environment Day 2006.

It was the first thematic UNEP's report on desert titled "Global Deserts Outlook" prepared by experts from across the globe and is part of Global Environment Outlook (GEO) series of environmental assessments.

In the report, the experts traced the history and astonishing biology of the deserts and assessed the likely future changes in deserts. The report said if the huge solar power potential of deserts can be economically harnessed, the world has a future free from fossil fuels. And tourism based around desert nature can deliver new prospects and perspectives for people in some of the poorest parts of the world, it said.

The report said over 500 million people live in the deserts across the world, which is significantly more than previously thought. The desert cores remain pristine in many parts of the world, representing some of the planet's last remaining areas of total wilderness.

The report, however, said the deserts are facing dramatic changes as a result of global climate change such as high water demands, tourism and salt contamination of irrigated soils.

The so-called 'sky islands'-mountain areas within the deserts which are important for people, wildlife and water supplies, are under particular threat, it said. Because of climate change, the overall temperature in the deserts increased between 0.5 and 2 degrees Celsius over the period 1976-2000, a situation which is much higher than the average global temperature rise of 0.45 degrees.

According to the report, while traditional American cities like Detroit and Chicago have seen population falls since the 1950s, desert ones like Phonix and Tucson, Arizona, have witnessed rise of populations from almost zero to between 500,000 and 1.5 million over the same period.

In some parts of the world, deserts are becoming increasingly attractive as places to live and to retire, but this often requires large pumping and water transfers, it said.

Most deserts have sunlight and temperature regimes that favour shrimp and fish farms in locations like Arizona to the Negev desert in Israel. Such ventures offer new and potentially environment-friendly livelihoods for local people and businesses.