| ALEXANDRIA, Egypt
ALEXANDRIA, Egypt Twenty years ago, Taher Ibrahim raced his friends across Alexandria's beaches, now rising seas have swept over his favorite childhood playground.
Alexandria, with 4 million people, is Egypt's second-largest city, an industrial center and a port that handles four-fifths of national trade. It is also one of the Middle East's cities most at risk from rising sea levels due to global warming.
"There were beaches I used to go to in my lifetime, now those beaches are gone. Is that not proof enough?" asked Ibrahim, a manager at a supermarket chain who is in his 40s.
Flooding could displace entire communities in Alexandria and the low-lying Nile Delta, the fertile agricultural heartland of Egypt's 79 million people.
The Intergovernmental Panel on Climate Change (IPCC) predicts that the Mediterranean will rise 30 cm to 1 meter this century.
More than half of Egypt's people live within 100 km of the coast. A 2007 World Bank study estimated that a one-meter sea level rise could displace 10 percent of the population.
Officials say salt water could submerge or soak 10 to 12 percent of farmland in the world's largest wheat importer.
"Climate change is happening at a pace that we had not anticipated," Suzan Kholeif of the National Institute of Oceanography and Fisheries told Reuters. "Our records are clear and in my line of work, it is already a reality."
But reliable data on local climate patterns is scarce and official responses are slow and uncoordinated, experts say.
Egyptian officials do not deny there may be risks but doubt the scale of Egypt's vulnerability, saying more research is needed.
"There are international assumptions that sea levels are rising but it isn't happening the way they talk about. We are studying all these scenarios to be prepared," Alexandria governor Adel Labib said.
More than 58 meters of coastline have vanished every year since 1989 in Rasheed, also known as Rosetta, said Omran Frihy of the Coastal Research Institute.
"There are hot spots, but that doesn't mean the whole Delta is at risk. Before we start talking about doom, we need to know where those spots are and act on protecting them," Frihy said.
Increased salinity seeping into underground waters will degrade farmland and cut production, experts say, in a country where food price rises have sparked unrest in the past.
Yet Egypt has no clear and unified climate change strategy.
"There are lots of plans but they are not integrated nor are they complete," said Mohamed Borhan, manager of a U.N.-supported project on how the Nile Delta can adapt to climate change.
"The right priorities are not set and the people working on the plans are failing in communicating," he said.
Some experts argue that uncertainty about the scale of the risk Egypt is facing makes it hard to adopt strategies.
"We are still assessing our vulnerability. There are adaptation options but we need to know what we are up against first," said Mohamed Abd Rabo, professor of environmental studies in Alexandria's Institute of Graduate Studies.
Winter storms have always flooded Alexandria's streets with sea water, but now waves crash against its courthouse on the inland side of the corniche, alarming some scientists who say water is infiltrating deeper than before.
The municipality has begun erecting coastal barriers to protect the corniche from flooding, but salt water intruding into underground reservoirs could be an even bigger concern for the city founded by Alexander the Great in 331 BC.
"Sooner or later, a disaster will happen but when, where and how, we aren't certain. But we shouldn't wait for a catastrophe to come knocking on our doors to act," Kholeif said.
Environment officials have increased inspections of industrial areas and have been pushing to cut greenhouse gas emissions in Alexandria, said Mona Gamal El Din, head of the city's branch of the Environmental Affairs Agency.
But even if industries obey regulations in Egypt, whose emissions do not exceed 0.6 percent of the global total, this would do little to reduce threats to biodiversity, Kholeif said.
A biologist, who has seen sea species disappear due to higher acidity, she said that with 108 endangered species Egypt was the Arab nation whose biodiversity was most at risk.
Taxi driver Ahmed Fattah said he doubted Alexandria itself would disappear beneath the Mediterranean but that he and his family could only wait and see.
"I worry that the government won't do anything until a crisis hits us. By then, we may be swept away by the waves."
(Editing by Alistair Lyon and Janet Lawrence)