Solar energy, ecotourism and even fish farms can create new jobs in arid regions of developing nations as global warming strains scant water supplies, a UN report said on Tuesday.

A four-year study of drylands in eight countries, ranging from China to Tunisia, showed that people could shift to less water-intensive farming and set up new businesses, sometimes helped by microcredits, to cope with climate change.

"We have to think outside the box, look at options where dependence on water resources is much lower," said Zafar Adeel, a co-author and director of the UN University's International Network on Water, Environment and Health (INWEH)

"Agriculture takes up to 70 to 90 per cent of freshwater supply in drylands," he told Reuters by telephone, quoting from a 42-page study entitled People in Marginal Drylands issued at a conference in Turkey.

One project near the Cholistan desert in Pakistan showed that largely untapped brackish water could be used for farming fish, a new source of protein for local people that could also be sold in local towns.

Ponds used for "arid aquaculture," using inland fish able to withstand high salt levels, produced more food than if the same volume of water was used to irrigate fields.

"If you can use the water for different purposes you multiply the benefits," Thomas Schaaf, a co-author and head of the Ecological Sciences and Biodiversity section at UNESCO, told Reuters. Pond sludge could be used as fertilizer.

Chickens rather than cattle to preserve vegetation

In a dryland region of Inner Mongolia in China, a shift to chicken farming from cattle herding boosted incomes and helped preserve vegetation from over-grazing.

"Instead of putting grasslands into cattle meat it was much better to put it into chicken meat," said Richard Thomas, deputy head of INWEH.

A project in Tunisia is developing ecotourism on the fringe of the Sahara desert. In Jordan, people are making "dryland soaps" based on olive oil and fragrances from local aromatic plants such as lavender, geranium, pomegranate and mint.

In Egypt, solar panels are used to power a desalination plant, bringing drinking water from underground.

As a spinoff, Egypt has started manufacturing solar-powered desalination units for use elsewhere — along the coast, salty water from the Mediterranean often seeps into groundwater.

Adeel said the examples were meant to help counter excessive pessimism about desertification blamed on global warming.

"When you paint a very gloomy picture the response is a non-response or paralysis at a policy level," he said. "We hope … some of these success stories lead to a larger-scale national response."

From 2009, projects will be launched in Burkina Faso, Bolivia and India.

According to UN data, drylands cover 40 per cent of the global land area and are home to nearly a third of the world's poplation, 90 per cent of whom live in developing countries.

The UN Climate Panel has forecast that global warming, blamed mainly on human emissions of greenhouse gases, will strain water supplies and cause deserts to spread.

With files from Reuters