CAIRO, Egypt - Climate change is likely to reduce agricultural production and exacerbate water shortages in the Middle East, threatening the region's poor, the UN Food and Agricultural Organization warned Monday.

Many countries in the Middle East already suffer from a shortage of arable land and limited access to water necessary to irrigate crops. But climate change could bring higher temperatures, droughts, floods and soil degradation, according to a new report released by the agency.

"Changes in temperature, rainfall and climatic extremes will only add to the stress on agricultural resources in a region where land availability and degradation, food price shocks and population growth are already a major concern," said the report, which is being discussed at a regional conference in Cairo.

Among the problems climate change could cause is an increased risk of conflict over the scarce resources, the report said.

Hunger and malnutrition caused by climate change will most likely affect those who are already poor, malnourished or dependent on local food production, according to the report. An additional 155 million to 600 million people may experience an increase in water stress caused by a rise in temperature by a few degrees, it said.

Many of the region's irrigation systems are already under considerable environmental strain due to salinity, waterlogging and overuse of groundwater.

Shifts in rainfall patterns will affect crops, particularly rice, in many countries, the report said. Yemen is particularly at risk given its existing low income levels, rapidly growing population and acute water shortage, the report added.

Many Mideast countries are already wheat and rice importers, and climate change may increase their reliance on imports at a time of rising prices.